Bulletin UASVM Agriculture, 68(2)/2011
Print ISSN 1843-5246; Electronic ISSN 1843-5386
Research Concerning Cucumber (Cucumis Sativus L. Mill) Genetic Diversity
Aurel MAXIM 1), Mignon ANDOR 1), Lucia MIHALESCU 2), Ovidiu MAXIM 1), Oana MARE RO CA 2), Veronica BOLBOAC 1)
1)University of Agricultural Sciences and Veterinary Medicine,
Calea M n tur, nr. 3-5, Cluj-Napoca, 400372, Romania, email:maxim0067@yahoo.com
2)The North University Baia-Mare
Abstract. During the second part of the twentieth century the cultivated plants have been faced with genetic erosion, because of the expandinding industrial farming systems. The sustainable agriculture can not exist without a rich genetic diversity.
After the United Nations Conference from Rio de Janeiro (1992), when the Convention on Biological Diversity was adopted, a series of acts and european references that protect agrobiodiversity had emerged.
Between 2007 and 2010, at the University of Agricultural Sciences and Veterinary Medicine a program which aims to identify and conserve local vegetable varieties was conducted. Out of 290 cultivars, 171 (58.9%) were genuine local varieties.
There were collected 12 cucumber cultivars from the following counties: Salaj (7), Cluj (3), Bistrita-Nasaud (1) and Satu-Mare (1). The morphologic caractheristics proved that all this 12 cultivars were authentic and valuable local varieties.
The local varieties were agronomical, biological and biochemical characterized, both in field and laboratory. The seeds achieved from those 12 local varieties were preserved in the Suceava Gene Bank, from where stakeholders (farmers, agronomists, researchers) can obtain seeds.
Keywords: agrobiodiversity, landraces, bioconservation, cucumbers, seeds, descriptors, gene bank.
INTRODUCTION
Biodiversity conservation in the agricultural landscape is a challenge during our time, challenge that arises from the need to understand the functions of agrobiodiversity – environmental and social – and their contributions for ecosystem and society [Hajjar et al., 2008].
Along his existence, the man used about 10.000 species of cultivated plants. Acording to FAO statistics, 90% of nowdays food output is ensured by about 120 species of cultivated plants. Besides the drastic reduction in specific diversity, the advent of industrialized agriculture has generated a strong proces of genetic erosion. The old cultivars and landraces of cultivated plants were the most affected in favour of modern cultivars. In the Directive 2008/62/CE, local varieties (landraces) are defined as ”a ensemble of populations or clones of a plant species that have naturally adapted to the environmental conditions of their region”
[Maxim, 2010].
As the definition sugests, landraces are characterized by high heterogenity. They have the advantage of being much better adapted to biotic and abiotic stress conditions (diseases, pests, drought, low nutrients etc.) and have excellent taste qualities, wich can justify a higher selling price compared with modern varieties. As a result of these features the crops need small inputs, wich coresponds to the concept or sustainable development. Landraces have an invaluable genetic potential for obtaining new varieties of plants and are best suited for crop
cultivation in ecological systems. Also, for long term food security in the context of global warming, rich genetic diversity will be required [Marin, 2009; Str jeru i colab., 2009;
Sanchez i colab., 2008].
In the EU, Romania is occupying the 6th place considering the area planted with vegetables after France, Spain, Poland, Italy and Germany with an area of 221.410 ha.
Growing vegetables in ecological systems is increasing continuously. In 2009 the area was with 15.7 % biger than in 2008 and the local varieties of vegetables are very well suited to this kind of crop systems.
Cucumbers are annual plants originating from India. The wild relative of cucumber - Cucumis hardwickii royale - is still found in the spontaneous flora of Himalayas’ subtropical valleys. Archaeological research indicates that the species was tamed 3000 years ago in the Indus Valley, then spread to China, Egypt and Syria. In Central Europe, cucumbers are cultivated for about 2000 years, according with archaeological data from Poland and Hungary.
Cucumber plants are monoecious (the male and female flowers on same plant) and they autopollinate. However cross-pollination is prevailing, that female flowers are fertilized with pollen from different plants of the same variety or plants of other varieties. The main pollinators are bees. To ensure the purity of variety it must be kept a distance of 400-1000 m between varieties. In the early stages of development the plants will have more male flowers then female flowers. The ratio between the two types of flowers is influenced by the duration and intensity of sunlight. Thus, long days and high sunligh intensity will promote male flower appearance, while short days and low light intensity stimulates the female flowers. Recent research shows that the largest number of female flowers are recorded on days with 11 light hours [Dominique, 2002].
MATERIALS AND METHODS
The 12 varieties of cucumbers were collected from four counties, from food markets or directly from vegetable seed producers. Most seed samples were collected from Salaj county (7), followed by the counties of Cluj (3), Bistrita-Nasaud (1) and Satu Mare (1). The localities altitude varies from 126 m (Satu Mare, Satu-Mare) to 465 m (Preoteasa - Salaj).
Following research conducted in the experimental field, it was found that 100% of the cultivars are genuine landraces - Table 1.
Tab. 1 Data concerning cucumber varieties (Cucumis sativus L. Mill) studied at
USAMV Cluj-Napoca in 2009 No.
crt. Variety
code County City Latitude Longitude Altitude
(m)
1. BN 361 Bistri a-N. M lu 47.17° N 24.07° E 250
2. CJ 359 Cluj Iclod 46.98° N 23.8° E 250
3. CJ 365 Cluj Ocna Dej 46.05° N 23.48° E 320
4. CJ 366 Cluj Ocna Dej 46.05° N 23.48° E 320
5. SJ 331 Salaj Preoteasa 47.12° N 22.73° E 465
6. SJ 333 Salaj Preoteasa 47.12° N 22.73° E 465
7. SJ 334 Salaj Preoteasa 47.12° N 22.73° E 465
8. SJ 335 Salaj Rona 47.08° N 23.28° E 270
9. SJ 368 Salaj Crasna 47.17° N 22.9° E 320
10. SJ 372 Salaj Crasna 47.17° N 22.9° E 320
Presented below are the basics of descriptors accompanying cucumber seeds in the Gene Bank of Suceava: code sample, observations on the plant (type of plant growth, plants type in terms of reproduction, resistance to aphids attack (Cerosipha gossypii), resistance to mite attack (Tetranichus urticae Koch), observations on the leaf (leaf margin size, intensity of green color of leaves), observations on the fruit – fruits length (cm), fruits width (diameter) - cm, the predominant shape of growth at the end of the fruit (calyx), the color of thorns, the predominant color of the fruits’ skin at physiological and consuming maturity, parthenocarpy, seed weight (100 seeds) - grams.
Overall, the crop technologies were the classic ones. No phytosanitary treatments were applied. Each variety was grown both in field and greenhouse. Resistance to pests (aphids, mites) was studied only in greenhouse. In 2009 the weather conditions were not favorable for mildew attack (Pseudoperonospora cubensis) and angular staining (Pseudomonas lacrymans).
The attack was sporadic in all varieties and could not draw conclusions about the resistance to these diseases.
Together with local varieties five cultivars of cucumbers (Pasalimo, Alibi, Mathilde,
Marketmore, Corni on) were also studied,
where stakeholders (farmers, agronomists, researchers) can getseeds.
RESULTS AND DISCUSSIONS
Based on morphological characteristics of plants was found that all 12 cultivars of cucumber are genuine local varieties.
The color of the cucumber fruit was determined at consumption and physiological maturity.
Tab. 2 The predominant color of the fruits skin at consumption maturity
White Yellow Green Other colour
number % number % number % number %
- - - - 11 91.7 1 8.3
The predominant color of the fruits skin at consumption maturity was green in 11 of the 12 studied varieties (Table 2). At physiological maturity the predominant color of the fruits skin was brown in 7 of the 12 local varieties and other color in 5 local varieties (Table 3). Tab. 3
The color of the fruits skin at physiological maturity
White Green Brown Other colour
number % number % number % number %
- - - - 7 58.3 5 41.7
To each variety of cucumber the resistance at mites attack by using 3 scales categories:
low, medium and high was measured.
The resistance at common mite attack (Tetranichus urticae Koch) was high in 9 varieties (75%) and medium in 3 of the varieties (25%) - Table 4.
To assess the resistance to aphids attack (Cerosipha gossypii), local varieties of cucumbers were placed in the following three categories of resistance: low, medium and high.
Fig. 1. Cucumber local varieties (UASMV Cluj-Napoca, 2007-2010)
Out of the 12 local varieties of cucumbers, 11 had a high resistance at aphids attack (Cerosipha gossypii) and one variety recorded a medium resistance (Table 5).
Cucumber production per hectare was determined for each variety at consumption maturity. The production was between 10 - 60 tons per hectare.
The production of cucumbers of local varieties ranged between very wide limits: 10 t/ha (CJ-359) and 56.1 t/ha (CJ-365), while the average production of the approved cultivars ranged between 15,8 t/ha and 18 t/ha (Table 6).
Tab. 4 The local varieties behaviour to common mite attack (Tetranychus urticae Koch) in greenhouse
Specification Resistance to common mite attack
(Tetranichus urticae Koch)
Tab. 5 The local varieties behavior to aphids attack (Cerosipha gossypii) in greenhouse
Resistance to aphids attack (Cerosipha gossypii)
Low Medium High
Specification
no. % no. % no. %
Landraces - - 1 8.4 11 91.6
Approved cultivars - - 2 40 3 60
Tab. 6 Production of cucumbers (Cucumis sativus L.) per hectare (tons)
Production per hectare (tons)
10-20 21-30 31-40 41-50 51-60
Specification
no. % no. % no. % no. % no. %
Landraces 2 16.7 6 50 2 16.7 - - 2 16.6
Approved cultivars 2 40 1 20 1 20 1 20 - -
Individual description of the 12 local varieties of cucumbers was based on characterization descriptors and the used terms were taken from these descriptors. Fig 1 presented overview and detail images selected landraces.
CONCLUSIONS
Preserving local varieties of crop plants are sine qua non condition of sustainable agriculture.
Between 2007 and 2010, at USAMV Cluj-Napoca were studied 290 peasant vegetable cultivars (tomatoes, cucumbers, carrots, parsley, lettuce) and among them were identified 171 (58.9%) valuable and genuine local varieties.
The 12 varieties of cucumbers were collected from the following counties: Salaj (7), Cluj (3), Bistri a-Nasaud (1) i Satu Mare (1). According to morphological characteristics all were classified as authentic and valuable local varieties. Local varieties were characterized from agronomic, biological and biochemical point of view, both in field and laboratory. The seed obtained from the 12 landraces of cucumbers has been preserved in the Suceava Gene Bank, from where stakeholders (farmers, agronomists, researchers) can obtain seeds.
REFERENCES
1. Dominique, G. (2002). The seeds of Kokopelli. A manual for the production of seeds in the family garden. Les Presses de Provence. Avignon. France.
2. Hajjar, R., Jarvis, I.D., Gemmil-Herren, B. (2008). The utility of crop genetic diversity in maintaining ecosystem services. Agriculture, Ecosystems and Environment 123(261-270).
3. Marin, D. (2009). Conservarea biodiversit ii. Note de curs. Editura Dominoz, Bucure ti.
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5. Sanchez, E., Sifres A., Casanas, F. and Nuez, F. (2008). The endangered future of organoleptically prestigious European landraces: Ganxet bean (Phaseolus vulgaris L.) as an example of a crop originating in the America. Genetic Resources and Crop Evolution 55 (45-52).
6. Str jeru, S., Ibanescu, M., Constantinovici (2009). Landrace Inventories: Nees and Methodologies. Biodiversity Technical Bulletin no 15. European Cooperative Programme for Plant Genetic Resources. Rome, Italy.
