• No results found



Academic year: 2020



Loading.... (view fulltext now)

Full text


Agrawal. World Journal of Pharmaceutical Research


Dr. Teena Agrawal*

Banasthali Vidhyapeth, Niwai.


Plant Pathology is the sciences of the culmination of the plant dieases study and there management. A number of the books have been written on the plant pathology, however some of the books have the much enlarged kinds of the description of the diseases, but in this book i have try to summaries the some of the main diseases of the plant diseases, however the world of the plant pathology is so long and deep that many edition of the book are very less. However the book is very valuable for the students of the B.SC as well as the M.Sc students who needs the short matter in good way.


Agrawal. World Journal of Pharmaceutical Research


Chapter Title Page No.

Chapter: 1 History of plant pathology. 1-8

Chapter: 2 Diseases caused by the plasmodiophoromycetes. 9-12

Chapter: 3 Diseases caused by the Chytridiomycetes. 13-15

Chapter: 4 Diseases caused by Zygomycetes. 16-18

Chapter: 5 Myxomycete a amazing slime molds group. 19-23

Chapter: 6 Peranosporales: a developed parasitic fungal group. 24-30

Chapter: 7 Family Perenosporaceae. 31-35

Chapter: 8 Foliar diseases caused by the ascomycetes and the deutetromycetes. 36-38 Chapter: 9 Diseases caused by the Ascomycetes and the Deuteromycetes. 39-41

Chapter: 10 Cladosporium Diseases. 42-45

Chapter: 11 Diseases caused by the Basidiomycetes. 46-54

Chapter: 12 Cercospora diseases. 55-56

Chapter: 13 Pyrenopohra dieases on wheat and barley and oats. 57

Chapter: 14 Rice blast diseases. 58-59

Chapter: 15 Rust of Flax. 60-62


Plant Pathology Introduction




Plant pathology is the sciences which is concerned with the detailed study of the plant diseases and there chemical control, the plant diseases always cause the devastating effects and they are responsible for the changes the culture and there ways for the living. Plant diseases are the result of the unfavourable environment condition and the interaction of the pathogen negatively. The branches of the plant pathology are very valuable and they are used for the protecting of the many kinds of the food crops an civilization as well as the cereals crops for the several kinds of the beneficiation.

It is estimated that the diseases together form and they are responsible for the annual loss of the many crops of the economic crops such as the fruits and the vegetables and the many of the cereal crops and the other kinds of the pulses and the many kinds of the food crops. Generally annually in the India as well as the countries like the USA and the other European countries the plant diseases are responsible for the damage for the annual loss of the 38-40 percent diseases. Plant forms the very valuable and the important part of the earth economy and they are the basis of the many kind of the ecosystem and there life cycles, the earth basic biogeochemical cycles are based on the interaction of the plants worth the environment. All parts of the plant such as the leaves, fruits and the seeds and the stem are very valuable and they are utilised for the several purposes for the fulfilment of the various kind of the needs of the humans bong in the different civilizations as well as the world. Even the food which comes from the animals also comes from the animals which indirectly depend on the plants for their diet and their basic needs.


Plant Pathology Introduction

Plant pathology is the study of the interaction of the organisms as well as the environment which causes the diseases. It also includes the methods for the preventing of the plants diseases for the various purposes. Plants are the basis of the life and they are responsible for the food as well as the medicines, so the diseases of the fungi and the plant pathology always causes the devastating effects and they needs the different methods for the saving of the plants for the various a means for the complete aspects of the plant diseases as well as it provides the way for the solution of the treatment of the diseases by the various means.

Uncontrolled plant diseases always was the ways for the reduced growth of the plants and their products and the sometimes the complete eradication of the plants from that area. Sometimes they effects the beauty of the landscape and the places and they are responsible for the complete eradication of the existing civilization form that area, there are several examples of the plant disuses which has causes the several devastating effects and they destroy the culture growth of the area. Diseases plant are responsible for the human diseases.

In the last 100 years the plant diseases are controlled by the chemical weapons like the different kinds of the herbicides and the fungicides and the heavy toxic chemicals. Controlling of the plant pathogens is the only form the superficial aspects but also from the soil so that they can eradicate the plant pathogens completely form the soil. However the heavy chemicals are very dangerous for the growth of the crops so they need the more effective and biologically safe methods for the controlling of the diseases. The biological methods are very safe and they eradicate the pathogens by the means of roots and they eradicate the pathogens by the eco friendly manners. The major methods for the controlling of the diseases are limited to the uses of the antagonistic methods of the controlling of the dieses and the many kinds of the plant breeding approaches as well as the many new genetic engineering methods for the controlling of the diseases.


Plant Pathology Introduction

changes the complete morphology of the concerned plants and they damage the plants from the roots to the top, diseases in the plant is the any invisible and the visible changes in the cells as well as in the tissues, due to the environmental and the pathogen interaction, which are responsible for the death of the concerned tissues as well as the other part of the plant, which leads to the death of the plant or the crops. any effected part of the plants such as the roots are also becomes rotten and they are responsible for the severe damage of the roots, the roots makes them unable for abortion of the metabolites and the water from the soil, infection of the xylem vessels leads to the plugging of the xylem vessels and they cause the bogging the vessels so that translocation of the food and the metabolites becomes hampers. Infection of the eaves leads to the formation of the spots, blights, rusts and mildews, mosaics and they interferes with the photosynthesis. infection in the phloem cell leads to the plugging of the phloem cells and they leads to the cankers, many of the small microorganism like the viruses, mollicutes and the Protozoa are he pathogens which plugs the sites of the phloem’s. Infected cells almost dies, infected cells results in the formation of the hyperplasia and the hypertrophy. Which turns in to the abnormal growth which leads to the formation of the many kinds of the galls form the minute kinds to the large one galles which appears very large and them disjunction the plant completely.


Plant Pathology Introduction

(Sources clathem journal news paper).

Different types of the plant diseases: From low to the several kinds of the plant pathogenic diseases results in the infection of the crops from the roots to the top of the tree or the crops. These crops affect the cultivated as well as the many kinds of the wild types of the plants. An each kinds of the crop plants can be effected by the from few to the several thousand types of the plant pathogens.

Plant diseases have been grouped by the many ways like on the basis of the symptoms spots, blights, rusts and the smuts, rots, wilts or some times on the basis of the plant organ they effects like the roots diseases, stem diseases, foliage diseases, or sometimes they have classified as the on the basis of the plant they effected like the turf diseases vegetable dieses and the crop disease.

Plants are diseases by the several means like they are affected by the way of the biotic agents and the sometimes they are affected by the a biotic methods, so the classification of the diseases on the basis of the agents have been done like this

1) Infectious diseases or the diseases by the biotic means:

Diseases caused by the fungi, diseases caused by the prokaryotes, diseases caused by the viruses and the viroids, diseases caused by the nematodes.


Plant Pathology Introduction

2) Diseases caused by the various abiotic means

Like the ph, drought, salinity and the pressures and the different kinds of the population, nutrition deficiencies mineral toxicities, diseases by the soil acidity.

Fig. 2: Different kinds of the plant pathogens (sources agriculture information bank).


Plant Pathology Introduction

Theophrastus wrote the two books on the plant pathology, one of them was the nature of the plants, in this book he describes the all the aspects of the plants world like the morphology, anatomy and the embryology, the another books was the reasons of the vegetable growth, in this books he includes the methods for the propagation of the plants, culture practices and the environmental condition for the propagation of the plants. In this book he mentioned the some of the plant diseases. Theophrastus has been considered as the father of the botany. The theory of the plant diseases and the description of the plant of the Theophrastus were based on the old beliefs and the old theories of those times. The control of the epidemics of the plant dieses was also not possible at that time, since there was lacks of the proper scientific knowledge, so the exact control measures for the control of the plant diseases was not acknowledge at that times. Efforts for the control of the plant dieses were also not possible due to the lacks of the knowledge and the lacks of the proper scientific knowledge of the plant diseases. However there are some reports of the control of the plants diseases by the chemical means, in this case the homer utilises the sulphur for the control of the plant dieses and the Theophrastus utilises olive oil for the control of the plant diseases from the extract of the olive oil.

However in much old belief system they were based on the belief on the god and the many other kinds of the Devi and the Devta of that community and that locality of that era.

Hover the exact era of the plant pathology was began from the 1200AD form the mistletoe research on the plant pathology. Peoples suffer from the hungers and the malnutrition’s due to partially to diseases destroy their crops. However they have not any options except to prey with the god to eradicate the dieses and to reduce the dieses form the society and from the field. In the mid 1600 century, there was the observation of the French farmers that wheat rust dieses was very severs in the place where the Barbary bushes grows nears by, the farmers observation was that the rust was produced in the Berbarry plants and from there it moves in to the wheat. So they ask the French government at that time to cut the berbarry bushes and passed the legislation to cut the bushes and to control the diseases.


Plant Pathology Introduction

peoples who in just the grain infected by the ergot. Later on research in the field of the microscope and in the field of the other branches of the sciences emerged to start and they start the branches of the plant pathology like in the files of the virology, Nematology, bacteria.

It was not until the discovery of the concepts of the origin of the species of the charales Darwin of the system nature in which they uses the all the principles of the nature and the natural selection and they revised the all existing principles, these theories of the Charles Darwin was the changing point of the all the principles of the file sciences.

The discovery of the microscope and there modification also embarks the era of the new plant pathology.

In 1729 the Italian plant pathologist Micheli, describes the new genera’s of the fungi and illustrated their reproductive structures. In 1755 the Frenchmen Tillet working on the smutted wheat, and they found that they can increase the number of the wheat plants by the means of the covered smut. He also noted that he can reduce the number of the wheat smut by reducing the smut by the way of the treating the smut by the means of the copperier sulphate. From the 1850 to the era of the 1900 that was the era of the development of plant pathology.

In 1800 centuries the diseases of the late blight of the potato was the very important dieses in the changing the pathway of the plant pathology.

In addition to that there was many more discovery were made according to the time in the field of the plant pathology.


Plant Pathology Introduction

the unfavourable conditions as well as they are the reasons for the fungi, bacteria and parasitic plants.

During the years of the Pasteur and the koches several scientist also work on the another and the several aspects of the plant pathology.

In the 19 the centaury the several other plant pathogens also known to causes the plant diseases such as the viruses, bacteria, nematodes and the prions the complex etiology of the plant pathogens was always the subject of the great concern and the great research. Among them the nematodes causes the reasons of the plant Nematology which is the very interesting branches of the plant pathology, since nematodes forms the complex reservoirs in the soil and they indirectly damage the crops.

Human are depended on the plants for their basic needs, the basic needs are the food, clothes and the medicines, the damage of the crops in any ways results in the heavy loss of the crops, which result in the damage of the millions of dollars annually in the India as well as the other parts of the world.

The death of the Irish civilization due to the famous famine of the potato, it was the Irish famine, was the significant step in the field of the plant biology.

Plant pathology goes in to the many ways in the 20 century however recently the era is the experimental plant biology and the basic focus is to develop the strategy for the control of the plant pathogens by the means of the chemical as well as the biological methods.


Diseases Caused by the Plasmodiophoromycetes



The members of the plasmodiophormycetes are the members or they are the endoparasites of the vascular plants and the stremanoplies, they are the necrotrophic endoparasite. They cause the abnormal enlargement of the cells as well as the abnormal division of the cells, the term has been known as the Hyperplasia. The result is the abnormal enlargement of the cells or the tissues, of the vascular plants due to the infection there is disruption of the vascular bundles or the vascular

elements. General stunting of the plants is the very valuable features and the shorting

of the tree is also the another significant part. The occurrences and the geographical distribution of the parasites of the plasmodiophormycetes concise with the hosts, some of the species are related to the aquatic plants such as the members of the stroamtophiles such as the diatoms, vaucheria, water molds Saproleginia, Achlya, Pytium. Some of the other species of the class parasite the some other members of the

aquatic plants such as the callitrichae, Isoetes, Zostera, Juncus. Some of them are based on the cabbage, sugarcane and the grasses, potato, Nasturtium, and veronica.

Plasmodiophora parasitca is the main fungus which parasites the crucifers, it is the

reasons for the club roots diseases of cabbage. The diseases are also known as the finger and toe diseases of the crucifers. Many other species of the plasmodiophormycetes are also the great vectors of the many of the diseases of the viruses induces disuses Myxomycetes members in many aspects and in many ways. Plasmodiophormycetes proceeds the multinucleate mycelium known as the plasmodia, however this plasmodia is totally differ from the plasmodia of the other. The life cycles of the plasmodiophormycetes involves the two phases one is the primary plasmodium which forms the zoospores, the thick walled resting spores capable for the perrenation and the survival.

Three plasmodiophormycetes causes the following three common diseases of the plants.

1) Plasmodiophora: causes the club roots of the crucifers.

2) Polymyxa: causing the root diseases of the cereal and the grasses.


Diseases Caused by the Plasmodiophoromycetes

The pathogens are the obligate parasites, some of the species of the palsmodiophoromycetes can survive in the soil for the long time. They can multiply and grow within the hours; the growth of the propagation of the species is very tremendous in the host and the other organisms. In some of the spices the pathogens invades and grow and it forms the enlarge cysts which is clear visible and they forms the galls, the pathogens spread by means of the spores form one plant to plants.

Polymyxa and the Spongospora in addition to the diseases, they cause and they are

responsible for the transmission of the plant viruses in to the host plants. Polymyxa graminis is the vectors of the many kinds of the viruses form the host plants.

Polymyxa betae is also the another reasons for the transmission of the beat necrotic

yellow vein viruses. Spongospora is also the reasons for the potato top, mop viruses.

Clubroot diseases of the crucifers: The clubroots diseases of the crucifer like the cabbage and the cauliflower are widely distributed all over the world, in India as well as other part of the world the cases of the clubroot diseases can be found.

Clubroot diseases of the crucifers may cause the serious damage to the host crops and the host plants. The pathogen of the clubroot dieses remain in the field forever and they generally not disintegrated, they effects the field productivity and the perrenation nature of the pathogen is responsible for the long survival of the pathogen in the soil.


Infected plants have the pale green to yellow colour appearance,

Later infected plant shows the wilting and the whole of the plant becomes the


Young plant is killed by the infection of the fungus.

The old plants have the reduce growth and they are incapable of producing the

head on the plants.


Diseases Caused by the Plasmodiophoromycetes

Pathogen: The pathogen is the Plamodiophora brasicae, the body is the plasmodium, the plasmodium gives rises to the zoosporangium,or to the resting spores. The resting spores on germination produce the zoopsores.

Development of the diseases: The single zoospores produces from the resting spores penetrates the root hairs and they develop the plasmodium, after few days the

plasmodium cleavage into the multinucleate portion and each develops in to the

zoosporangium, each zoosporangium contains the 4-6 secondary zoospores, the

zoospores are discharged outside the host wall by the means of the pores, some of the

zoospores fuses in to the zygotes, the zygote cause and infection and they produce the

plasmodium, theses zoospores penetrates in to the host tissues by means of the pores

and they penetrated by means of the wound. Form theses points they spread in to the

cortical cells, after that the plasmodium spreads in to the whole of the cortex and the

vascular tissues.

As the plasmodium lives in the cortical tissues, they abnormally induce the cell to become enlarge and they form the hypertrophy, some of the cell divide and they forms the hyperplasia.


The plasmodium infected cells or the roots are not able to utilise and they are full of the contamination. They interferes the translocation of the nutrient and the other water translocation in the body. The result in the general stunting and the reduced growth.


Diseases Caused by the Plasmodiophoromycetes

Figure 2: Diseases cycles of the club root diseases (sources: vegetable md online cornell university).

Control measures

 Avoidance e of the cultivation of the crucifers crops in the field.  A PCR based assay is based which identify the zoospores in the field.  The ph of the soil should be adjusted.

 Soil fumigant can be used for the treatment of the soil.

 The clean clubroot free seedling can be grown for the eradication of the diseases.

Some of the Varity of the crucifer are resistant, so there cultivation can reduce the growth of the pathogens in the fields.


Diseases Caused by the Chytridiomycetes



The members of the chytridiomycetes are commonly known as the chytrids, they lack the true mycelium, the mycelium is in the form of the irregularly branched of the thallus is made up of the chitin, the thallus entry lives in the host tissues. On maturity of the vegetative body are transformed in the resting body or the sporangia.

Chytridiomycetes are the soil inhabitation fungi, they generally harbours the soils as well as the water. Since the members produce the zoospores, so in the stages of the life cycle they acquire the water for the propagation of the species. The class chytridiomycetes contains the three basic plant pathogenic genre, theses genera follows as the Olpidium, Synchytrium, Physioderma, they causes the following dieses respectively Olpidium infects the roots of the many kinds of the plants, Syncytrium which causes the black wart of potato. Physioderma which causes the crown wart of alfalfa.

The fungi survive in the soil as the resting spores, or in some of the case they can be found in the host tissues or in the host thallus. The resting spores germinate to produces the zoospores. The phylum chrtirdiomycota contains the single class termed as the chytridiomycetes; the members of the chytridiomycetes are good that they produce the motile stages in the life cycles. Some of the other features of the chytridiomycetes are as follows,

1) The coenocytes structures of the mycelium.

2) The diploid mycelium converts in to the resting body, that is called as the resting mycelium which helps in the perrenation of the mycelium.

3) The cell wall is made up of the chitin and the glucan.


Diseases Caused by the Chytridiomycetes

Most species complete their life cycle in few seconds and in the few hours within the day.

Since many of the species are minute, so they can be seen by the way of the

microscopy. There are considerable variations in the thallus structures and the

asexual as well as the sexual reproductive structures. The simplest forms are the

endobioitc forms, which lives in the tissues of the host cells. Some of the species are

the epibiotices, since in some of the stages they lives outsides the body of the host.

In eucarpic forms, the Rhizoids agree hairs like structures, through which the rhizoids are attached and seem part of the body are utilised for the formation of the fruit body.

Sexual reproduction in the chytrids has been reported by the variety of the methods such as the Planogametic copulation, this is followed by the isogamous planogmates conjugation. Another methods are the copulation of the anisogamous planogmates copulation, fertilization of the nonmotiles gametes by the motile’s gametes, by the gametagial copulation, soamtogamy.

Asexual reproduction occurs by the means of the zoospores’ rather than any other things. The zoospores are discharged from the sporangium by the means of the papillae.

Traditionally the class has been divided in to the orders on the basis of the morphological features of the sporangium and the other somatic reproductive structures. Chytrids has been described as the sister groups of all other fungi in the plant kingdom.

Orders: Spizelllomycetales: The order was established by the Barr in 1980, the members are the free living and the plant parasites, they are typically saprobes as well as mild pathogens.

Genus Rozella, Genus Olpidium

Order: Neocallimasticlaes: They harbours the rumen and the caecum of the herbivores animals. The five genera are the Neocalliamstix, Orphinomyces, Piromyces. The members are the obligate anaerobes. The famous genus is the


Diseases Caused by the Chytridiomycetes

Order chytridiales: The members are the soil inhabiting and the soil inhibiting fungi, some parasites the protozoa and algae, some of the better known genera are the Chytriomyces, Polyphagus.

Rhizophium, Endochytrium, Synchytrium, Cladochytrium, Nowakowskiella Order

balstocladiles, the members are the chiefly soil inhabitating and they are the typical aquatic. Some of the members are as follows Allomyces, Genus Blatocladiella, Blastocladia, Coelomyces, Catenaria.

Order Monoblepharidles: The members are of typical of the fresh water and they acquired the soil as well as the other parts.

Late blight potato diseases: The genus consists of the 100 species, which are parasitic on the crop plants. These are endobiotic and the Holocarpic fungi, the sporangia are the in opererculate. In synchytrium the thallus is colonial, the Thallus divided in to the several spores which are incorporates in the sorus

The fungus causes the hypertrophy and the hyperplasia which causes the abnormal enlargement of the plant tissues.

Sometimes the galls formation also occurs, and they are responsible for the destruction of the tissues. Asexual occurs by the means of the zoospores’ and the sexual reproduction occurs by the zoospores which fuses and produces the zygote, the zygote is the means for the perrenation of the new generations.


Diseases Caused by Zygomycetes



Zygomycetes are the fungi having the well developed mycelium, the mycelium has not the cross walls, the spore are nonmotiles, they are produced in the sporangia, the main features is the resting spores known as zygospores, the zygospores are produced in the non-motiles sporangium, the two sporangium can be similar or they can be dissimilar, heterothallism can be seen in theses fungi, Zygomycetes are the typical terrestrial fungi, the spores of the fungi can be seen floating in the air, they are weak parasites or they can be saprophytes. Generally they cause the soft rots or the many kinds of the diseases on the vegetables or many other plants of the commercial values. Some of the species are the typical parasites of the humans.

Three genera of the zygomycetes are responsible which causes the diseases, these are the Choenophora, the genus causes the diseases in many kinds of the cucurbits, after the time of the fertilization and they invades the fruits and flower together.

The another genera are the Rhizopus and the Mucor( most famous fungi) they causes the Molds and the soft rots of the fungi, theses fungi are commonly known as the bread Molds.

Plant pathogenic Mucors are the weak parasites. They generally grow in the form of the saprophytes and in the form of the weak parasites, even they infect the living plant tissues but the basic mode of the nature of the fungi is saprophytic.

Rhizopus soft rots of the fruits and vegetables: Rhizopus rots of the fruits occur on the


Diseases Caused by Zygomycetes

whole of the tissue become softy and pulpy. The whole of the mycelium remain collected beneath the surface and the sporangiophores, the sporangiphores gives rises to the sporangia. The effected tissue initially gives the some bad smell, later on whole of tissues disintegrates by the cultivation of the differ types of the bacteria and the other microbes. If the infection is very high, than they swap the slimy water from the tissues and disintegrates them.

The mycelium of the fungus produces the long, septate sporangiophores, which bear the terminal sporangia. The sporangia contain the thousands of the spores in it. The mycelium grows and they produce the stolons, theses stolen are the points of the attachment of the mycelium from the substratum. Adjacent hypae produces the progametangia, theses progametangia come close together, the wall of the progametangia fuses, before that the tip of the progametagia separate from the rest of the gametangia by the septa formation. The progametangia fuses and they form the zygopsores. The zygopsores are the resting phase; it is the method of the perrenation of the fungi. After germination it produces the prosporangium, the prosporangium produces the several spores, by which the fungi disseminates the spores.

Diseases cycle: The fungi propagates by the means of the spragiophores, afters the getting the appropriate kinds of the host,they propagate and they lend on the exact cells and starts propagates, they produces the Pectolytic enzymes, theses enzymes produces the lytic cell wall are responsible for the degradation of the whole of the tissues.Later on the whole of the mycelium start penetrating the whole tissue and they invades the all the parts, they produces the sporangia, spores and the other contents after the maturation the fungi produces the progametangia, theses progamtangia fuses from the tips and they produces the zygospores, these are the resting body and they are the means of the perrenation of the fungus at the adverse condition.


Diseases Caused by Zygomycetes


The diseases resistance variety should be used and propagated.


Myxomycetes A Amazing Slime Molds Group



The members of the Myxomycetes are commonly known as the slime molds. Theses organism exhibit the phagototrophic mode of nutrition in the life cycle. They produce the following life stages in the life cycle multinucleate somatic phase called as the plasmodium, a resistant phase called as the sclerotium, the uninucleate cells which are flagellate (used in fusion). There occur two types of the cell division, one of them was the centric cell division, and another cell division is the centric, Myxomycetes is the cosmopolitan group, they can be found in the Varity of the habitat, even in the lawn, flower bed, generally they are found the moist temperate forest. Myxomycetes have prove very valuable not only for the mycologists but also they are very valuable for the cytologists, genetics, molecular biologists, biophysicists and the biochemists. The members of the Myxomycetes are very useful, since they show the early evolution of the life, the life cycle of them any of the fungi are very interesting and they destroy of the host in severe way, in some of the cases they reside in the host tissue. Overall the Myxomycetes is very important group of the fungal kingdom.


Myxomycetes A Amazing Slime Molds Group

fecal matter. Slime molds are very common on the dung while some of the fungi are also found on the dung substrate. Another habitat of the fungi is the dead branches of the living tree. Some of the genera are like the stemonits are found on the fence and the rotting chamber in the house, fences.

Slime molds virtually have not any economic significance. However they are valuable in the food webs, however it has been reported that the scelrotia or the fruits of the Enteridiun lycoperdon has been eaten as the coked food in some of the place of the

Mexico tribal area.

Myxomycetes have been studied by many peoples, the first recognizable literature of the Myxomycetes have been provided by the Apnkow in 1654. However it was the Antony de bary who gives the more detailed account of the life history of the Myxomycetes in 1858. Debary differentiates the true slime molds from the cellular slime molds on the basis of the formation of the plasmodium. basey, kudo and debary has find put that the slime molds have the protozoan ancestor. Myxomycete have been termed as the slime molds and they have the phagoptrophic mode of the nutrition. In the life cycle of the Myxomycetes, there occurs three stages, theses are enlisted as 1) Three types of the uninucleate cell among them one was the flagellates,

2) A multinucleate somatic phase, known as the plasmodium. In this protoplasm one can see the scuttle moving cytoplasm.

3) A resisting stage consisting of the scelrotium.

Additionally Myxomycetes exhibit the two kinds of the cell division, one of them is the centric kind of the cell division and another kind of the acentric kind of the cell division.

The plasmodia and the sporophores of the spices often appear in the lawns.


Myxomycetes A Amazing Slime Molds Group

the thread like structures this are known as the capitiltium. The order have been described as the monophyletic, however the true phylogenetic relationship of the orders has never been reported.

Spores: Spores of the endopsorous Myxomycetes are liberated from there sporophores by a Varity of the factors, including the wind, water, the activities of the animals, theses spores are globose with a definite rather thick wall, the surface of the spores are smoothly, thick walled, reticulate and they are lanceotalete. The spores of the Myxomycetes are appears to be the unexceptionally resistant towards the unfavourable conditions.


Spores dispersal: The dispersal of the spores occurs by means of the air currents, more recently the role of the arthropods also have been seen in the case of the dispersal of the spores.

Figure 1: Myxomycetes life cycle (sources driftless praries).

Spores germination, myxoamoebae, swarm cells


Myxomycetes A Amazing Slime Molds Group


amoeboid structures. The mitotic divisions are the intranuclear and they do not follow the other pattern involving the centrioles.

Figure 2: Myxomycetes life cycle pattern (sources: peoi).

The plasmodium often has the multinucleate mass of the protoplasm; the streaming of the protoplasm in to the plasmodium is the features of the very taxonomic values. Three basic kinds of the plasmodia are described in the Myxomycetes, theses are enlisted as the smallest types the protopalsmodium, like the species of the Licea. the another kinds of the aphanopalsmodium, examples are the stemonitales. The third one is the phaeroplasmodium, they are represented by the physarales. The fourth types of the mycelium was found in the Trichalies.

Scelrotia: In the normal phase the plasmodium gives rises to the Sclerotioum, that can be dormant for the long times. Sclerotia can be indices in to the mycelium by the way of the germinations.



Myxomycetes A Amazing Slime Molds Group

1) Liceales 2) Echinostellies 3) Trichiales 4) Physlaresles 5) Stemonitales 6) Ceratiomyxelss.



Peranosporales: A Developed Parasitic Fungal Group



Members of the perenosporales are the most specialised form of the oomycetes. The order is the very large and they include the members which are aquatic, terrestrial and the amphibious in form. The members are the highly specialised obligate parasites. Many of the species are the destructive parasites of the host plants and the crop plants. Majority of the species causes the great epiphytotices in the crop damage. The damping of diseases of the fungi, the white rusts of crucifers and downy mildew of the cereals all belongs to these orders. The control measures of theses pathogens are still is a very big problem and they are the challenge for the plant pathologists.

The mycelium of the perenosporales is well developed. The hypae is the coenocytic and they are the branched, the hypae of the parasitic species are intracellular as well as the intercellular. The haustoria of the various shapes and they grows between the two cells. The haustoria of the parasitic perenosporales is the features of the taxonomic values, the shape of the haustoria has been utilised for the identification of the species, like the haustoria of the Albugo candida are spherical in shape, the haustoria of the Perenospora pisi are the slightly elongate, the Phytopthora infestens have the elongate kind of the haustoria.

Asexual reproduction: This mode of reproduction in the perenosporales is quite similar with the other orders like the saproleginiales, Leptomitlaes. The asexual reproduction occurs by the way of the sporangia, the sporangia produce the zoospores, they are quite differing from the rest of the sporangia of the other members. In some of the genera of the perenosporales, the sporangium have the multiple division and they forms the zoospore whereas in some of the members the whole of the sporangium converts in to the whole of the spores and they are utilised for the reproduction.


Peranosporales: A Developed Parasitic Fungal Group

The classification of the oomycetes is based on the characters of the sporangia and the spragiophores. The well defined families of the perenosporales are as follows; these are the pythiaceae, perenosporaceae, albugoginaceae. These families are formed on the basis of the morphology of the asexual bodies. The sporangia and the sprangiophores.

Members of the Pytiaceae generally bears the sporangia on the directly on the Hypae, in this case the fertile hypae are totally different form the rest of the somatic hypae.

The sprangiophores are of the indeterminate growth and they are arranged like the tip has the young ones and the base has the oldest kind of the sporangium.

The sporagiophores of the perenosporales are of the determinate growth and they bears the branched types of the sproangiophores, in that prospective the two of the sprangiophores are of the different from the rest of the Pythiaceae.

Species of the albugoginaceae are of slightly differ from the other group, like they have the short chains and they have club shaped sporangium that bears chains sporangia on the tip. The sporangiophores are of the indeterminate growths in this respects they differ from the other group.

Family: Pythiaceae: This family includes the aquatic, amphibious, terrestrial fungi,

the terrestrial fungi causes the serious loss of the economic crops. The mycelium is well developed; haustoria are produced in some species. The morphological differtiation of the hypae from the rest of the sexual hypae is same; there is not any morphological differentions in the mycelium.


Peranosporales: A Developed Parasitic Fungal Group

Figure 1: Life cycle of Phytiaceae (Sources: wikibooks).

The sporangia reproduce by means of the asexual as well as the sexual means, the germination of the sporangia is by the germ tube, or in some of the cases they liberate the zoospores in the natures. The germination of the sporangia whether it is by the germ tube or it is by the zoospores are governed by the environmental factors.

Sexually the oomycetes have the oogamous kinds of the reproduction and they forms the oospores, in some of the species the oospores produces Parthenocarpy.

Genus Phytium, the damping off diseases: The members of the genus Phytium are the soil inhabitating microorganisms. They occur all over the world. They are generally found in the soil, they are the severes plant pathogens in the cultivated soil and they cause the devastating effects of the serious agronomic ally important crops.


Peranosporales: A Developed Parasitic Fungal Group

seedlings near the soil line and they damage the seedlings form the soil line. Due to infection the seedlings are not able to survive and they fall of from the soil.

The species of the Phytium are responsible for the pre emergences and post emergences of the seedlings from the field. The post emergences damping off the seedlings are the main reasons for the disintegrating of the plants in the field. This condition of the damping off can be seen in the green houses and in the orchard, where the Phytium species destroy of the main crops from the field.

The young mycelium of the Phytium survives in the soil as saprobic fro the long times and parasitically in the living hosts and the produces the diseases. In host tissues the hypae are the intercellular as well as the intracellular. In this case no haustoria are produced. Soft fleshy parts such as the squash, cabbage, beans and potato are rotted by the Phytium fungi. The genus contains the about the 120 species, majority of the species of the Phytium are soil inhabitation. The taxonomy of the genus is depend on the zoosporangia and the oogonia morphological value, however there is a huge plasticity in the characters of the morphology, so now a days the emphasis is on the other characters such as the serum and the nucleic acid, like the molecular approaches for the correct identification of the fungus and their species.

The mycelium of the Phytium debrynium consists of the slender coenocytic mycelium, without the septa and the other features of the ascomycete’s fungi or the basidiomycetes fungi. The mycelium lives in the soil as the saprophytic and in many cases they lives as the parasitically on the young seedlings.


Peranosporales: A Developed Parasitic Fungal Group

The oospores are the final structures by which the fungi perennates and they are the means of the propagation of the fungi, the oospores germinates by the way of the germ tubes and after germination they produces the zoospores,the new zoospores after germination starts the new infection.

Genus Phytopthora: The genus Phytopthora is very widely distributed and highly pathogenic genus of the perenosporales, the Phytopthora is different from the rest of Phytium by the means of the sporangia germination and the way of the arising of the

germ tube form the mycelium. The systematices of the Phytopthora genus is based on the morphological features of the zoosporangia, gamantangia and the zoospores liberation. About 50 species of the fungi have been recognised by the various means, however the number of the fungi can be more, it is based on the several kinds of the morphological feature as well as the taxonomy of the antheridia as well as the oogonia and the other reproductive features. Erwin 1983 describes that the number of the species of the Phytopthora are much more than the previously described, Lucas et al describes the new techniques and they utilises the new techniques for the analysis of the new species of the genus Phytopthora.


Peranosporales: A Developed Parasitic Fungal Group

Figure 2: Life cycle of the Phytopthora species (sources : wikibooks).

The mycelium of the fungi survives in the soil in the form of the remnants, the oospores of the fungi are the resistant structures and they are the means of the survival of the fungi in the hard conditions or in the tough conditions. A typical heterothallism can be seen in the fungi mycelium and in the groups, and they are responsible for the producing of the characters.

Phytopthora differs from the rest of the fungi by the means of the sproagiospores; the

sizes and the shape of the sproangiophores are quite different from the rest of the mycelium. The formation of the sprangiospores are the indication of the differentiation of the thallus. The sprangiophores are sympodially branched and they have the indeterminate kind of the growth pattern.

The shapes of the sporangia are lemon shaped and they are totally morphologically distinct. The transfer of the sporangia a takes place by the way of the water and the air.


Peranosporales: A Developed Parasitic Fungal Group

by the germ tube in the higher temperature and they germinate by the zoospores in the low temperatures, zoospores float on the surface of the leaves water and they germ tube of the zoospores produces the approsorium from which the minute pegs’ are arises and they enter in to the leaves and the other parts by the germ tube. The germ tube enters by the stomata.

The zoospores have the very good and significant role in the dieses development. The zoospores after germination produces the profuse mycelium under the leaf surface, the intercellular Hyphae produces the branched haustoria, which help in the absorption of the nutrient form the host cells. At the favourable condition the mycelium produces the profuse sporangiospores and they produces the abundant sporangia, they start the abundant asexual life cycles.in one growing season the abundant asexual generations are produced.


Family Perenosporaceae



This highly specialised family is famous for the obligate parasitism; the members are the typical parasites of the vascular plants. The diseases of the members are commonly called as the Downy mildews. Downy mildew plants of are the typical parasites and they parasites the all of the agronomically important plants, the downy mildew is the most common diseases produced by the downy mildew fungi, some of them are as follows, the downy mildew of the grapes by the Plsmopora viticola, downy mildew of the onion as the Plasmopora destructer, the downy mildew of the lettuces, theses are by the Bremia letaceae, downy mildew of cucurbits by the Pseudoperenospora cubnensis, mildew of the grasses by the Perenospora maydis.

Plasmopora viticola has the very important history, like the history of the

Phytopthora infestens. The fungi was responsible for the development of the

treatment of the diseases by the fungicides, of the downy mildew of the grape veins, Professor millardet of the university of the Bordeaux was the person who first time watch the utilization of the chemical matters for the treatment of the downy mildew diseases of the fungi in Europe. It was the long story that how the fungi was inserted in the USA by the vector, and how the whole of the vineyards were destroy by the fungi, than accidental observation (like the penicillin of the Alexander penicillin) begins the era of the chemical fungicides. Number of the genera of the orders which are separated by the way of the branching of the sporangiospores exist in this family, here the sporagiopsores of the perenopsoracae are different from the sporangiospores of the Phytiaceae, since on the basis of the determinate growth they are separated from the sporangiopspores of the Phytiaceae.

Description of the genera‘s of the perenosporacae on the basis of the sporaniospores structures and the branching patterns.


Family Perenosporaceae

Figure 1: Sporangiophores of the Perenosporacae (sources: biology discussion).

The sproangiophores of the Perenosporaceae are different from the rest of the families of the orders in the pattern of the growth they have the determinate growth pattern, the sporangia are produced on the strigmeta and on the tip they have strigmeta are the branched and on the tip they have the sporangia. The shaped of the sporangia are lemon shaped or the oval. They are deciduous and they all are wind disseminated.


Not all the members of the family like the Perenospora and the Pseudopernospora are not germinating by the zoospores, while they are germinate by the means of the germ tube. Oospores of the genera germinate by the means of the zoopsores or by the means of the germ tube. The pattern of the life cycle of the Perenosporaceae follow the same pattern as the Phytiacae and the Phytopthora.


Family Perenosporaceae

Family Albugoginaceae: The members of the family are known as the white rusts. All the members are the obligate parasites and they infect the vascular plants. There are several species of the Albugo but the Albugo candida is the only one species which infect the crucifer’s plants. Some of the other species of the Albugo are as follows, A. ipomoeae panduraane on the sweet potato, A.portulaceae on portulacae. A occedentalis on spinach, A.bilti on various members of the amaranthaceae.

In A. candida the mycelium is intercellular, and they feeds by means of the haustoria they penetrates the host cell wall by the means of the minute perforations and they extend and form the knob like haustoria. The mycelium grows in the host tissues and ramifies beneath the host cells. The sporagiopspores are produced on the mycelium at the time of the reproduction; on the tip of the branches one can see the sporangia, the sporagiophores forms near the close proximity beneath the surface and aggregates there. Albugo germinate by the means of the germ tube as well as by the way of the zoopsores, the germination depend on the temperature conditions and the other factors of the environment. The sexual reproductions of the Albugoginaceae is same like the other members of the perenosporales, the reproduction occur by the means of the antheridia and the oogonium, the matures oospores are main body, they are the means of the means of the presentation of the species in the adverse conditions. Germination occurs by the germ tube or in some of the case by the means of the germ tube.


Family Perenosporaceae

composition of the oomycetes. Most of the species are of the aquatic forms and they are found in the forms of the saprobes. They have the major role in the aquatic ecosystem; they have the role in the degradation of the various kinds of the aquatic substances.

The majority of the oomycetes are the facultative or the obligate parasites of the higher plants, some of the diseases of the oomycetes are of the great economic values, they causes the serious diseases of the angiosperms and they are responsible of the major diseases of the angiosperms which causes the serious and heavy loss of the angiosperms.

Some of the examples of the heavy losses of the dieses are as follows as, late blight of potato, avocado root rot, root and fruit rots of the citrus, downy mildew diseses of the cucurbits, grapes, onion, lettuces, white rust of the crucifer, two of the devastating pathogens are the, one of them is the late blight of potato, downy mildew of the grapes, the causal organism are the Phytoptora infestens and the Palsmopora viticola.[1][2][3][8][9]

The members of the oomycetes have the branched mycelium, the mycelium is the uniseptate, holocarpic forms, filamentous species formed of the profuse mycelium, coenocytic mycelium, septa are absent at the base of the reproductive organs, sometimes the hyphe of the aquatic forms of the oomycetes forms the extensive growth and they cover the whole of the mycelium, hyphae grows in the host in the forms of the intercellular as well as the intracellular forms. Hyphe of the intracellular forms tends to grow profusely and the collects in beneath of the tissue. The members of the obligate parasites tends to grow and they forms the haustoria in the leaf and the other part where the mycelium resides.[1][2][3][8][9]

Cell wall of the oomycetes have the cell wall composition made up of the glycan or the glucose or the cellulose, the cell wall of the oomycetes are made up of the beta 1,3 glycans.[1][ 8][9]


Family Perenosporaceae

of the gametangia, the one of them is the thread like male organ, this is termed as the antheridia, the female organ composed of the globose organ termed as the oogonia.

They can be developing from the same mycelium or from the other mycelium. On the meiosis the female gametangia forms the oospheres in the oogaonia, the oospores has the peripherals oospores and the periplasm, on the fertilization the fertilization tubes arises and they forms the connect ion between the male and the female reproductive organs.[8][9]

Asexual reproduction occurs by means of the the two flagella these are the heterokont types, the reproduction is basically by means of the zoopsores.

In the case of the terrestrial oomycetes the, sporangia are swollen, they are lemon shape and swollen.

After the germination two kinds of the zoospores are arices, one of them is termed as the primary zoospores and another of them has been termed as the secondary zoospores. The secondary zoospores are the kidney shaped. The flagella are inserted at the laterally on the bean shaped zoospores.[4][6][7][10]

In the sexual reproduction oogamous kind of the reproduction has been seen, the two sex organs are of the two differ shaped, one of them is the anthredia and the another one is the oogonia, the resultant of the sexual reproduction is the oospores, so the reproduction is the oogamous types.[11]

Some of the orders of the oomycetes are as follows, these are the saproleginiales, Rhipidiales, Lagenidilaes, Perenosporales.



Foliar Diseases Caused by the Ascomycetes and the Deutetromycetes



Many of the ascomycetes are the foliar diseses, however some of them are the fungi which causes the diseses on the other plant parts such as the stem, flowers, roots and the seeds but this part of the fungi is basically concerned with the folia diseses, most of the foliar fungi reproduces asexually as well as sexually, the asexual means of the reproduction is by the conidia and the sexual reproduction occurs by the fruiting body, the fruiting body works as the means of the perrenation of the fungi in the duff seasons.

Some of the foliar fungi produces the ascocarps and the other fruiting body and theses structures are the basic means of the reproduction of the fungi. Common types of the ascomycetes fungi which cause the folius dieases are as follows:

The primary inoculums are the conidia and the other spores which reside on the leaves and the other fallen parts of the plants. They are the reasons for the germination of the conidia in the next seasons.

Some of the most common Ascomycetes the fungi, which causes the foliar dieses are as follows:

Cochilobolous: several species of which cause the leaf spots, blights, m and root rots

on most cereals diseses and grasses.

Blumeriella: causing leaf spot of cherries and plums.

Magnphorthae: M. Ulei: causing south American leaf blights

Dothistroma: D. pini causing needled blights of pines.

Lirula: needles blights of spruces.

Lophodermium seditiosum: causing needles blights of pines.

Mycospherella: M. Musicola; causing sigatoka diseses of banana.

Pyrenophora: causing leaf spots.


Foliar Diseases Caused by the Ascomycetes and the Deutetromycetes

The foliar symptoms of most of the deuteomycetes fungi are very similar and they follow the same cycle and same pattern of the pathogens infection and the propagations.

Most of these fungi attacks by means of the conidia, on the infected parts numerous kinds of the conidia are produced and are as folllws, the they spread on the other plants tissues by the means of the wind and the rains and by the contacts. In most of the cases the conidia rest on the other plant parts and the plant debris.

Alternaria diseases: Alternaria diseses usuaaly appears as the leaf spots, and blights.

The pathogens are also responsible for the damping off the fungi in the field. Some of the most common dieses of the Alternaria are as follows. Early blights of potato, early blights of tomato.

The leaf spots are dark brown to black often numerous and enlarging, usually the symptoms appears in the form of the concentric rings.

The appearances of the spot is like the target board like appearances, the lower leaves are attacked first, later on the symptoms are progressed on the upper parts of the plants, the leaves turns yellows and the brown and they becomes shrinks, the productivity of the leaves are also effected very much.

Alternaria may effects the whole of the plants or the other plant parts on the basis of

the severity of the infections.

The pathogens: the pathogens is the Alternaria, the species depends on the different kinds of thes hosts, like the early blights of the potato caused by the Alternaria solani, the shape of the conidia are of the great taxonomic values, they have the long septa and the many kinds of the traverse and the longitudinal septa, the beak of the conidia is also very large and pointed. The conidia are carried out by the wind and the rains and the other agents. Alternaria occurs on many kinds of plants throughout the world. There spores are present on the air and many other places.


Foliar Diseases Caused by the Ascomycetes and the Deutetromycetes

has never been seen in any other part of the plants. The sexual stages of the fungi have been transfer in the new genera’s of the ascomycetes.


Control: Alternaria diseases are controlled by the uses of the diseases resistance Varity. Sometimes the uses of the chemical sprays is the another way of controlled of the fungi. The plant debris and the other leaves should be burned and they should be eradicated, so that the harbouring of the fungi can be stopped.


Diseases Caused by the Ascomycetes and the Deutetromycetes



Ascomycetes and mitosporic fungi previously called as the fungi imperfecti. the members of the Deutetromycetes and the ascomycetes are closely resemble to each other, both of the classes produces the mycelium, which are the haploid, the mycelium has the cross walls, both produces the conidia, the conidia’s are produces in the many kinds of the fruiting body, the types of the symptoms are produces are also very common, these symptoms are the leaf spot, blights, cankers, fruit rots, anthracnose, stem rots, root rots, vascular wilts, the soft rots. The only difference between the two fungi is that ascomycetes produces the sexual spores where as the deuteromycetes new procedures the sexual spores. They reproduces by the parasexual mitosis, there is complete absents of the meiosis, so there is not the exchange of the genetic material, the members of the ascomycetes reproduce by the means of the ascospores, mycelium, conidia a and the together kinds of the fruiting body. There is a great anomaly that many of the fungi which were later were included in the deuteromycetes are now placed in the ascomycetes due to the production of the ascospores in the different kind of the fruiting body.

So at the level of the evolution it has been speculated that majority of the deuteromycetes are actually the ascomycetes fungi, which have lost of the power of the sexual reproduction at the courses of the evolution.

By the phylogenetic study of the deuteromycetes it has been revealed that the deuteomycetes constitutes the unnatural phylogenetic assemblage, which has diverted during the courses of the evolution, during the courses they ahs lost the power of the sexual reproduction and reproduce by them means of the only asexual reproduction. The DNA phylogenies shows that the deuteomycetes are splitting lines of the evolution of the ascomycetes fungi and it is the best examples of the degenerative evolution.


Diseases Caused by the Ascomycetes and the Deutetromycetes

such as the perithecia. The Glomerella fungi produces the Anthroconose diseases of the plants.

Ascomycetes produce the ascospores, the ascospores are produces in the ascus. They reproduces by the means of the conidia, the conidia are the asexual spores. The sexual stage are termed as the teleomorph. The asexual stages are termed as the anamorph.

The usual processes of the reproduction of the ascomycete’s fungi are typical and it is very similar to the all other genera’s of the ascomycetes. The male body is the anthredium and the female body is the ascogonia, the reproduction occurs by the Ascogenous hyphae.

The fruiting body is termed according to the differ terminology, these are the Perithecia, clesitothecia, Pseudothecium, sporodochia, acervuli, Apothecia.

Leaf curl diseases of the Taphrina: several species of the Taphrina causes leaf, flower, fruit deformation, on the stone fruits and the forest trees, they causes the severs damage theses damage are the on the losses of the peaches, nectarine and sometimes plums. Taphrina diseses occurs all over the world.

Some of the symptoms of the Taphrina are as follows, the defoliation of the peaches, the severs symptoms are the closing of the fruits. In many cases the whole of the leaves are deformed and curled downward.

The affected leaves produces the asexual ascospores on the leaves, later on the symptoms are spreads on whole of the plants and the other parts. The overall the whole of the plants part are affected and they losses the complete production of the crops.


Diseases Caused by the Ascomycetes and the Deutetromycetes


the tissue, at the ascus the time of the reproduction the asci accumulates and they produce the ascus and the ascus produce the ascospores,the number of the ascospores are in the 8. The asci produces the great pressure on the cuticles, as the cuticle splits, the development of the diseses occurs du e to the unfavourable environmental conditions and on the susceptible variety.


Cladosporium Diseases



The members of the Deuteromycetes produces different types of the diseases on the Varity of the hosts, one of the dieses is caused by the genus Cladosporium, the genus has the number of the species, they includes the leaf mold diseases of the tomato. The diseses is caused by the Cldosporium flavum, cucumber scab is caused by the C.cucumerium, C.carpophium, scab and leaf spot by the C. caryigenum, Blight of pea

caused by the C.caldosporodies.

Tomato leaf spot are the dieses which is caused by the differ member of the green houses and the in the field grown tomato. the tomato grows in the high humidity, the symptoms appears as the green yellowish green spots, they first appears on the old leaves, later on the progress on the young leaves also, alter the leaves spot enlarges and they fuses and they cover the entire areas, Later on all the parts of the leave s are covered by the whole of the fungus.

Peach scabs and the blights are the major reasons for the great and the severes economic losses of the crops in the different season, symptoms appears in the form of the small patches, later on the symptoms enlarges and they covers the whole of the areas, cucumber scab appears in the form of the patches and the gummosis, theses spots appears in the form of the sunken areas. Theses spots sometimes appear in the form of the oozes. Theses oozing sometimes produce the fluid, theses fluid is the main methods of the propagation of the pathogens in the adverse conditions.

The fungus overwinters in the form of the mycelium and in the form of the conidia in the plant debris and on the waste materials.

Needles casts and blights of the conifers: Several Ascomycetes fungi such as the

Elytroderma, Hypoderma, Lophoderma, Mycospherella, Lecanosticta, Dothiostroma,

Plioderma and other causes the leaf diseses on the pines. Whereas the Rhabdoclines,

Rhizosphera, Phaeocrytopus, Lirula and other infect the leaves of the other conifers

such as the Douglus fir,Spruce and balsum fir respectively.


Cladosporium Diseases

of the conidia and the spores, theses spores are the ascospores. the fungus enters in the leaves by the way of the ascospores and the conidia, theses fungus produces the yellow spots or the Hello, later on theses hallows develop in the hard parts and the hard cracks. The entire leaves are cracked and they attaches on the twig of the tree or the branches.

Sometimes the ascospores are produced in the perithecia, which are released in to the air and the way of the water they are distributed in the different conifers plant parts and on the different pines.

In most of the cases the fungi overwinters in the form of the conidia and the ascospores. Needles cast or the blights can be very destructive in the green houses and in the fresh field, they are responsible for the degradation of the pines in many areas.

Every year thousand of the tree of the pines is cut down due to the blights and the other kinds of the spots. Theses blights and the cast can be devastating in the green houses for the young seedlings.

In most of the cases the young seedlings and the pines cast and the blights can be controlled by the spry of the fungicides and the eradication of the diseased seedlings form the field.

The soil treatment of the soil is also the very useful and the important step in the eradication of the diseases.

Mycospherella diseases: The genus is charterised by the several kinds of the diseases

of the diverse natures in the different fruits and the vegetables. The anamorphs are the several kinds of the genus like the Cercospora, Septoria. The Mycospherella are the sexual stages and the other are the asexual stages, they lives on the many kinds of the s in the crops.


Cladosporium Diseases

The diseases severity affected the whole of the leaf areas, so the photo synthetic area are affected and hey reduces the whole productivity of the crops are reduced, these results in the formation of the less small banana and the tree the other parts of tree.

Symptoms: The dieses first appears in the form of the long streaks and in the form of the long spots, later on theses streaks spreads in the whole areas. Such spots lead to the degradation of the whole of the leaf area and there is the less production of the leaf productivity and the fruits.

Pathogens: The pathogens is the Mycospheralla musicola, anamorph Pseudocercospora musae. The black pathogens were discovered in the 1972. In

the1980 the black Sigatoka has the wide appearances of the sigatoka diseases. The fungi has the typical characters of the Deuteromycetes fungi, they produce the s the sporodochia and the perithecia, as the form of the asexual body. The sexual body produces the peritheica, which have the sexual hypahe. The asexual reproduction occurs by the means of the conidia. Conidia are produced by the asexual division and they are spread by the means of the air and the water to the neighbouring plants. Perithecia are produced during the warm weather, and ascospores are the basic sexual spores for the perennation and the propagation of the diseases.

Control of the diseases: The diseses are controlled by the means of the sanitation practices, as well as by the utilization of the fungicides, the quarantine department is the also another department by which the diseses can be controlled. The Zineb and the copper oxychloride mixing with the oil water fungicides give the best result for the protection of the crops from the severes diseases.


Fig. 2: Different kinds of the plant pathogens (sources agriculture information
Figure 1: Club root diseases of crucifers (sources: Ta zitter vegetable md online).
Figure 2: Diseases cycles of the club root diseases (sources: vegetable md online
Figure 1: Wart diseases of potato (sources: resnet.wm.edu - College of William


Related documents

A good number of the famous battles in the Hundred Years War started as English chevauchée raids where the French caught and forced the English to battle.. The famous

“God in the form of pure, bright white light flowing through my entire body, mind and soul is purifying and healing apus, pridhvi, vayu, tejas, akash, my home, my DNA, and all

Phulner can then replace that function so that the taint is retained and a vulnerability has been injected, because user input which has not been sanitized is outputted on the page..

(G –J) DiI-labeled EVs, isolated from supernatant of control uninfected cells, were stained with anti-gB AF647 antibodies and anti-gH PB antibodies or with their isotype controls..

These test data, and those from many other researchers, highlight the benefits to be obtained in terms of reducing sulphate attack and chloride ion penetration from incorporating

Other readings (not required): Pearson, Neil D., 2002, Risk Budgeting: Portfolio Problem Solving With Value-at-Risk (New York: John Wiley & Sons), Chapters 11, 12, and 13;

Precisamente la relación entre ―cuerpo‖ y ―tecnologías de la comunicación‖ –territorio donde se ubica este texto– hace mucho más complejo el análisis

This set comprises publication output indicators such as (1) the share in the world total, (2) subject-based publication profiles, (3) citation-based indicators like journal-