Top PDF Efficient Partitioning of Assimilates in Stress-Tolerant Groundnut Genotypes under High-Temperature Stress

Efficient Partitioning of Assimilates in Stress-Tolerant Groundnut Genotypes under High-Temperature Stress

Efficient Partitioning of Assimilates in Stress-Tolerant Groundnut Genotypes under High-Temperature Stress

Haulm weight and pod weight obtained per plot were converted into haulm yield (Hy) and pod yield (Py), expressed in g m −2 and used to determine the total biomass (Bt) given as: Bt = Hy + (Py × 1.65). The pod weight was multiplied by a correction factor of 1.65 to adjust for the differences in the energy requirement for producing pod dry matter compared with vegetative part [ 50 ]. Harvest index (HI) was determined as a ratio of adjusted pod weight to total biomass, given as: HI = (1.65 × Py)/Bt. For each plot, days to 75% flowering, days to maturity, pod yield (kg ha −1 ), kernel yield (kg ha −1 ), hundred kernel weight (g), sound mature kernel (%) and oil content (%) were recorded. Oil content was estimated with near infrared reflectance spectroscopy (NIRS) (model XDS RCA, FOSS Analytical AB, Sweden, Denmark) using whole kernels [ 51 ]. Two physiological parameters, crop growth rate (CGR) (g m −2 day −1 ) and pod growth rate (PGR) (g m −2 day −1 ) were estimated following a modified procedure given by Williams and Saxena [ 52 ]. Stress susceptible and tolerance indices were calculated to identify heat-tolerant genotypes using the following formula:
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HEAT-STRESS EFFECTS ON DRY MATTER PARTITIONING, POLLEN VIABILITY AND FRUIT YIELD IN TOMATO GENOTYPES

HEAT-STRESS EFFECTS ON DRY MATTER PARTITIONING, POLLEN VIABILITY AND FRUIT YIELD IN TOMATO GENOTYPES

Flowering and fruit setting are highly heat sensitive processes of tomato plant (Dane et al. 1991, Singh and Shono, 2003, 2005) and relate directly to yield. We observed significant reduction in pollen fertility (Fig. 5) and germination in tomato genotypes, when heat-stress was imposed at flowering stage, though the magnitude of reduction was less in heat tolerant genotypes than the sensitive one. Pollen viability (Pressman et al. 2002, Salem et al. 2007) and fertility (Dane et al. 1991, Suzuki et al. 1999) have been reported to be reliable parameters for better plant productivity during heat stress. Higher pollen fertility and viability in heat tolerant genotypes could be due to enhanced membrane thermostability of anthers and membrane integrity of pollen tube (Shivana and Cresti 1989). Wolters-Arts et al. (1998) reported involvement of lipids in directional pollen tube growth and it seems that desaturation of lipids in pollen tube is responsible for higher pollen germination and tube length in heat tolerant genotypes. Pressman et al. (2002) suggested that the effect of heat-stress on pollen viability was associated with the carbohydrate metabolism in various parts of anther during its development. The heat-stress induced decrease in the sugar concentration in pollen grains is possibly responsible for decreased pollen viability. Synthesis of low molecular weight heat shock proteins and their mRNA has been reported in pollen of Nicotiana tabacum (Shono et al. 2002). It is possible that these HSPs play a role in the tolerance of pollen grains to high temperature stress. The heat-stress induced diversion of dry matter towards vegetative (stem, roots) instead of
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Assessment of Groundnut under Combined Heat and Drought Stress

Assessment of Groundnut under Combined Heat and Drought Stress

Plant responses to high temperature vary with plant species and phenological stages (Wahid et al. 2007). Reproductive processes are markedly affected by high temperatures in most plants, which leads to reduced crop yield. For example, both grain weight and grain number appeared to be sensitive to high-temperature stress in wheat, as the number of grains per head at maturity declined with increasing temperature (Ferris et al. 1998). Vara Prasad et al. (2000) investigated the effects of day- time soil and air temperature of 28 and 38 C, from start of flowering to maturity of groundnut, and reported 50 % reduction in pod yield at high temperatures. These authors observed that day temperature above 34 C decreased fruit-set and resulted in fewer numbers of pods. However, Greenberg et al. (1992) and Ndunguru et al. (1995) reported that varieties grown by farmers in the Sahel yielded well in the hot months prior to the onset of the rains, and this has been attributed to their ability to maintain partitioning to pods above that in normal tem- peratures. Here, we test the range of genotypic variation in pod yield under hot conditions, using a large and rep- resentative set of genotypes.
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Protective role of antioxidant enzymes in chickpea (Cicer arietinum L.) genotypes under high temperature stress

Protective role of antioxidant enzymes in chickpea (Cicer arietinum L.) genotypes under high temperature stress

From the foregoing discussion it is clear that exposure of chickpea genotypes to high temperature stress for a medium duration of thirty seven days i.e., 78 to 115 DAS resulted in increase in the activity of superoxide dismutase, ascorbate peroxi- dase and glutathione reductase. The temperature tolerant genotypes Pusa-1103 and BGD-72 exhi- bited a comparatively higher superoxide dismu- tase, ascorbate peroxidase and slight decline in glutathione reductase compared to susceptible genotypes Pusa-256 and RSG-991. Efficient anti- oxidant enzymes status in tolerant genotypes under high temperature condition reflected in lower membrane injury index, higher relative water content, chlorophyll and carotenoid content com- pared to susceptible genotypes Pusa-256 and RSG- 991. Hence selection of genotype based on these criteria may help in evolving chickpea genotypes tolerant to high temperature stress with better yield.
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Change in oil fatty acids composition of winter oilseed rape genotypes under drought stress and different temperature regimes

Change in oil fatty acids composition of winter oilseed rape genotypes under drought stress and different temperature regimes

Among non-living stresses, drought is the most important restricting factor of plant growth and agricultural production all over the world, in par- ticular in arid and semi-arid areas (Sun et al. 2013). Winter oilseed rape (Brassica napus L.) has the third rank in the world’s vegetable oil supply, and it is the fifth rank in terms of protein (Jaberi et al. 2015). The fall, winter, and early spring rainfalls meet the winter oilseed rape’s water need during the grow- ing season; however, in most of the areas, the most critical growth stages, namely, flowering and podding stages, may have no celestial precipitation. Hence, the damage caused by drought stress in different growth stages will be different. Genetic differences also exist in tolerance to drought stress in a wide range of plants, such as winter oilseed rape (Kauser
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Assessment of genetic diversity and effect of peg induced drought stress on groundnut (arachis hypogaea l.) genotypes

Assessment of genetic diversity and effect of peg induced drought stress on groundnut (arachis hypogaea l.) genotypes

Five selected primers gave total of 52 amplification products, out of which 34 were polymorphic (Table 2). Among the primers of OPA and OPD series, 5 primers produced scorable and reproducible amplifications in all the genotypes. Maximum polymorphism was showed in PCR reaction with primer OPD-02 and showed 100% polymorphism in size ranging from 1 to 2 kb. They were closely followed by OPA- 03 with 60% polymorphism. The banding pattern of primers OPA-05 and OPA-10 was found to be identical with many primers and in case of primer OPD-02, total number of bands were 15 out of which 15 were polymorphic. The size of amplified products varied from 500 to 2000bp (Fig. 1-5). Banding profiles obtained with 5 random primers for 8 groundnut genotypes were analysed on the basis of presence and absence of the bands. Jaccard’s similarity co-efficient between the isolates were calculated (Table 3) and the similarity matrix thus produced indicated that Dharani and Kadiri 9 were genetically distinct as they showed only 40.9% similarity followed by Kadiri-9 and Narayani with 41.3%. While the genotypes Narayani and Dharani were found to be genetically similar with 86.8% similarity followed by 78.4% similarity between JL24 and Greeshma, 77.8% between Kadiri 6 and Abhaya, 70.8% between Kadiri 9 and Greeshma. The similarity co-efficients subjected to SPSS software produced a dendrogram with two major clusters (Fig. 6). First cluster having Narayani and Dharani with first sub-cluster TPT 3 and Kadiri 6, second sub-cluster having Kadiri 6 and Abhaya. Second cluster having Greeshma and JL24 with sub-cluster Greeshma and Kadiri 9. Genotypes JL24 and TPT 3; Dharani and Kadiri 6 are distantly related and from separate branches as they were not grouped with these clusters.
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Light Regulated Osa miR169e Is Implicated during Priming under High Temperature Stress in Rice

Light Regulated Osa miR169e Is Implicated during Priming under High Temperature Stress in Rice

In an earlier study, using NGS based computational analysis, we showed that ~45% osa-miRs were deregulated under high temperature stress (HS) [32]. Among them osa-miR169 was one of the largest families represented by 19 members that were regulated by cues from light and HS. miR169 is a highly conserved family and its expression levels are influenced by different abiotic stress conditions [17] [23] [34]. Our previous study indicated that some members of miR169 family that were heat up-regulated in PB1, were differentially down-regulated or absent in the tolerant rice variety N22 [32]. It has been clearly demonstrated that miR169 negatively regulates the transcript level of NF-YA subunit [35] and thus may potentially regulate many aspects of plant life including primary root elongation, flowering, gametogenesis, seed development, abscisic acid signaling, and res- ponses to HS, drought and light [36] [37].
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Alleviation of Salinity Stress In Groundnut by Application Of PGPR

Alleviation of Salinity Stress In Groundnut by Application Of PGPR

Abstract- Two high salt tolerant Plant Growth Promoting bacteria(BM6, AMAAS57) were isolated from Gujarat kuttch region. Their PGP characters were characterized at lab by different biochemical test. To study their ability to promote growth of plant under salinity, pot trial was conducted using groundnut. Different physiological parameters (carbohydrate, phenol and free amino acid, SLA, RWC) were studied. Two pseudomonas culture having plant growth promoting tratits like production of IAA, HCN, ammonia, phosphate solubilisation, antifungal activity and tolerant to salinity (10% NaCl). These cultures were identified by 16s rRNA sequencing viz. Pseudomonas aeruginosa AMAAS57 and Pseudomonas aeruginosa BM6. Application of Pseudomonas aeruginosa AMAAS57 increased the production of phenol and free amino acids with soil salinity of 2 ds/m but thereafter decreased gradually with increasing salinity the decrease as compared to control. application of Pseudomonas aeruginosa AMAAS57 lowered the level of RWC% with increase in salinity. Application of Pseudomonas aeruginosa AMAAS57 and Pseudomonas fluorescens BM6 reduced the electrolyte leakage.
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Performance of canola (Brassica napus l.) genotypes under drought stress

Performance of canola (Brassica napus l.) genotypes under drought stress

No. of days from sowing to 50% flowering, plant height, number of branches, silica and seed/plant, oil and protein percentage, seed, oil protein yield/ha in both 2014/2015 and 2015/2016 seasons. Physiological growth indices were reduced under drought stress. This condition can be the most important environmental factor for the increase of total dry matter of control of irrigation [17]. A long term drought stress effects on plant metabolic reactions associates with, plant growth stage, water storage capacity of the soil and physiological aspects of plant. Canola is one of the most important oil crops in the world[1].The agricultural use of water in the world is more than 85% of total water use, moderate to severe intermittent or terminal drought is a common occurrence, and dry most crops cannot be grown without supplemental irrigation [2].Regularly, water deficit stress has detrimental effects on many processes in plants, which include reducing photosynthesis, accumulation of dry matter, stomatal exchanges, and protein synthesis that affects their growth stages[18,19].Grain yield showed high sensitivity to water deficit, proving that irrigation can definitely benefit crop grain yield [20]. Generally, plants respond to water deficit stress through developmental, biochemical and physiological changes and the type of the observed response depends on several factors such as stress intensity (SI), stress duration and genotype [21]. The stresses imposed at a later stage of development, reduce sink size, shorten the duration of seed filling and decrease the opportunity of crop to recover. Irrigation had more influence on seeds per pod than other yield components and water deficit influenced flowering to maturity stages more than other growth stages [5]. Water stressed conditions, those of rapeseed cultivars which were able to maintain their relative water content at high levels had a higher seed yield. Since water stress during seed development did effect on the sink size (seeds per plant), decreased source capacity led to reduction of seed weight [22].A similar result was reported by[3,4,5,6,23].
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Root characterization of bean genotypes (Phaseolus vulgaris) under drought stress

Root characterization of bean genotypes (Phaseolus vulgaris) under drought stress

The clustering method allows determination of which parents would be useful for obtaining new hybrids, based on the magnitude of their dissimilarity and the potential of the progenitors. Accessions grouped in the most distal clusters are the most genetically dissimilar and thus adequate for crossings. It is well known that individuals with the same dissimilarity pattern should not be crossed to avoid restricting genetic variability and prevent negative effects on selection gains. However, in this case, it is necessary to check whether the numbers of whorls and basal roots are correlated with traits of interest, such as grain yield. Based on Tocher divergent clusters, 47 genotypes were selected for the number of whorls and basal roots. These represented the genetic dissimilarity among all accessions for water deficit assessment at the pre-flowering stage (Table 3).
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PROGRESSIVE CHANGES IN BIOCHEMICAL CHARACTERS OF SUGARCANE GENOTYPES UNDER SALINITY STRESS

PROGRESSIVE CHANGES IN BIOCHEMICAL CHARACTERS OF SUGARCANE GENOTYPES UNDER SALINITY STRESS

Progressive stress responses were studied in contrasting sugarcane genotypes to elucidate the stress adaptative physiological and biochemical characters. Varieties showed differences with respect to parameters studied from the day four onwards. The tolerant variety Co 85019 maintained stability of plastid pigments (chlorophyll and carotenoids), higher proline concentrations and increased activity of oxidative enzymes. Sensitive genotype showed large reductions with regard to these characters. Lipid peroxidation, a measure of damage to the membrane system was higher in sensitive variety and difference between genotypes became significant from day four, indicating the progressive nature of adaptation in tolerant and its failure in sensitive varieties.
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Evaluation of Leaf Protein Pattern in Wheat Genotypes Under Drought Stress

Evaluation of Leaf Protein Pattern in Wheat Genotypes Under Drought Stress

Drought is one of the most important factors limiting crop yields around the world. Drought stress in plants, the change (increase or decrease) in the production of plant proteins. This research was carried out using bread wheat genotypes. For evaluation of leaf protein pattern in wheat, 10 genotypes were assayed with 3 replications under irrigated (non-stress) and rain-fed (stress) conditions. At grain filling stage, 10 random plants were selected and flag leaf samples were harvested. SDS-PAGE Electrophoresis was used to evaluate protein pattern after applying water stress. Thirty five protein bands appeared. Most of the bands were similar in the entries and specific bands were rare. Under drought stress, high molecular weight proteins were intensified, while low molecular weight proteins were faint. Cluster analysis under non-stress conditions classified the genotypes into tree clusters but under stress conditions the entries were classified into four clusters.
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Adaption of Wheat Genotypes to Drought Stress

Adaption of Wheat Genotypes to Drought Stress

Abstract— Drought can serve to restrict the growth and development of wheat. The current research was conducted to screen for drought-tolerant wheat genotypes through phenotypic markers, including growth indicators and yield. We used a Randomized Complete Block (RCB) design with three replicate sites (about333 m 2 area per replicate). Six wheat genotypes which are frequently grown under rain-fed conditions at the southern highland of West-Bank, Palestine were evaluated for specific phenotypes including stem length, spike with awns length, awns length, number of tillers, total grain, total hay, and mass of seeds (per 100). The results showed significant variations among the six wheat genotypes for most of the measured parameters. Yellow-Hetia genotype showed the highest stem length, spike with awns length, awns length, weight of 100 seeds, and yield (grain plus hay). However, the remaining genotypes presented almost similar production ranging from 475-488 kg/dunum. In contrary, Nab-El-Jamal genotype exhibited the lowest grain production and Um-El- Rabee’ genotype revealed the minimum hay production. Based on our data, Yellow-Hetia could be a promising cultivar for future breeding programs, especially those involving drought tolerance.
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Response of Sugar Beet Genotypes under Salinity Stress in Central Areas of Iran

Response of Sugar Beet Genotypes under Salinity Stress in Central Areas of Iran

The effect of salinity treatment on number of plants per hectare was not significant (Table 1). This issue is very important in assessing the effects of salinity, as it indicates that the decrease in growth and yield in saline conditions is not due to the low number of plants, but the salt stress in this regard. Regarding the fact that the sugar beet plant is very sensitive to salinity stress during plant establishment, and having enough plant to understand the effects of salinity stress it was necessary, so we used non- saline water for irrigation until plant establishing stage. However, plots in saline condition at the beginning of the growing season had a higher salinity, which was due to leaching with irrigation of 8 dS.m -1 before planting (Fig.
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Characterization of TaDREB1 in wheat genotypes with different seed germination under osmotic stress

Characterization of TaDREB1 in wheat genotypes with different seed germination under osmotic stress

In order to define the expression patterns of the three TaDREB1 homologues and their relationship with osmotic stress tolerance, semi-quantitative RT-PCR analysis was carried out to determine the expression levels of TaDREB1-A, TaDREB1-B, and TaDREB1-D in two wheat genotypes differing in seed germination osmotic stress tol- erance, using the ACTIN gene as an internal control. The results showed that the transcriptions of TaDREB1-A and TaDREB1-B genes were not detected in dry seeds and seeds treated with − 1.00 MPa mannitol for 12, 24 and 36 h via agarose gel electrophoresis. However, the expression level of TaDREB1-D had the tendency to increase gradually and then decrease when treated with − 1.00 MPa mannitol for 0 h, 12 h, 24 h and 36 h. Higher transcript expression level was detected in seeds treated by mannitol than in dry seeds. The highest transcript expression level came from osmotic stress-resistant line 08–1783 for 24 h treatment and from osmotic stress-sensitive variety Zhangye 1 after 12 h treat- ment (Fig. 3).
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Comparison of Spray and Point Inoculation with Fusarium graminearum to Evaluate FHB Disease in Two Winter Wheat Genotypes Under Temperature Stress

Comparison of Spray and Point Inoculation with Fusarium graminearum to Evaluate FHB Disease in Two Winter Wheat Genotypes Under Temperature Stress

Results of evaluation of Type 1 and Type 11 resistance in the current study is consistent with other findings that mid- anthesis is the most susceptible stage and temperature may play significant impact on disease severity. An addition to these findings was the possible effect of incubation temperature of 23/15°C on DON concentration following point inoculation. Whilst [9] reported that Type I and Type II resistance might be governed by different loci which measure different resistance reactions, [6, 14] associated major resistance QTL for low FHB severity with low DON content in wheat and barley. Longer duration of flower opening experienced under low temperature might explain the higher DON in point inoculation. Previous experiments showed no temperature difference at inoculation at mid-anthesis, so the difference observed in this experiment could be attributed to the timing of temperature stress and may also be responsible for the genotypic difference found in FDK. Stressing the plants a day after inoculation may have had greater influence on spray inoculation and particularly Rht-D1b; unlike in the previous studies where pots were transferred into growth cabinets days after inoculation. FDK is very important in wheat breeding programmes as this is normally the preferred parameter when evaluating wheat breeding lines for FHB resistance [15]. As observed by [9], no genotype combines different levels of both Type I and Type II resistance and often the differences between both types of resistance are marginally significant. This may explain the non-significant genotype x method of inoculation interaction observed in all the parameters. Number of grains per spike, grain weight and grain yield were neither affected by genotype or temperature but strongly influenced by the method of inoculation. This suggests that the method of inoculation can be considered to be more stable than either the incubation temperature or genotype, as it affected the different parameters measured. The higher grains lost recorded following spray inoculation
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SHORT COMMUNICATION PHYSIOLOGICAL CHARACTERIZATION OF RICE GENOTYPES UNDER PERIODIC WATER STRESS

SHORT COMMUNICATION PHYSIOLOGICAL CHARACTERIZATION OF RICE GENOTYPES UNDER PERIODIC WATER STRESS

water 85% is used by Agriculture sector alone of which 75% is used for rice cultivation (Kirloskar, 2003). Irrigated rice requires lot of water, about 3,000-5,000 liter of water is used to produce 1 kg of grain (IRRI 2001). This high requirement of water for rice cultivation is because rice is generally grown under lowland conditions. In lowland rice fields, seepage and percolation account for 50-80% of the total water outflow from the field (Sharma 1989). Evaporation makes up about 30% of evapotranspiration and only 13-33% of total water flow is consumptive water use by transpiration. To mitigate the increasing water scarcity in Asia it is necessary to develop a new way of growing rice that use less water while maintaining high yields.
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PIGMENT CONCENTRATION AND ACTIVITY OF ANTIOXIDANT ENZYMES IN ZINC TOLERANT AND SUSCEPTIBLE CHICKPEA GENOTYPES SUBJECTED TO ZINC STRESS

PIGMENT CONCENTRATION AND ACTIVITY OF ANTIOXIDANT ENZYMES IN ZINC TOLERANT AND SUSCEPTIBLE CHICKPEA GENOTYPES SUBJECTED TO ZINC STRESS

Physiological parameters like shoot dry weight, chlorophyll ‘a’, Chlorophyll ‘b’, total chlorophyll, carotenoids, soluble protein content, catalase, peroxidase and superoxide dismutase activities were higher in case of zinc tolerant genotypes as compared to zinc susceptible genotypes at pre and post flowering stages of plant growth. The grain yield of chickpea genotypes was positively and significantly correlated with all the physiological parameters except peroxidase and superoxide dismutase activities. At pre-flowering stage grain yield was positively correlated with catalase activity (r=0.450*) and total chlorophyll (r=0.583**), while at post flowering stage grain yield was positively and significantly correlated with shoot dry weight (r=0.435*), total chlorophyll (r=0.470*), soluble protein (r=0.566**) and catalase activity (r=0.604**). From the above results, it can be inferred that total chlorophyll content, catalase, carotenoids and soluble protein are important contributing parameters towards chickpea production under zinc deficient condition. Hence, these parameters can be used as traits for screening/developing zinc stress tolerant genotypes. On the basis of per cent grain yield response, genotypes, viz. FG 897, BG 1084, CSJ 128, PBG 126 and CSG 9505 were identified as tolerant, whereas BG 372, BGM 535 and BG 256 were identified as susceptible to Zn stress.
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Physiological responses of chickpea genotypes for drought tolerance under induced moisture stress

Physiological responses of chickpea genotypes for drought tolerance under induced moisture stress

ater, the most important component of life, is rapidly becoming a critically short commodity for humans and their crops. Shortage of water limits plant growth and crop productivity in arid regions more than any other single environmental factor (Boyer, 1982). Chickpea (Cicer arietinum L.) is a staple food of the world. It is one of the most important pulse crops which provide more calories in the form of starch and proteins; besides vitamins and diet than any other food crop. Water stress reduces crop yield regardless of the growth stage at which it occurs in chickpea. Arid and semi arid environment besides other factors may induce water stress during crop growth and development, results a reduction in crop yield (Ashraf et al., 1995). In spite water stress is recognized as an important factor that affects chickpea growth and yield, differences among cultivars were found in response to soil moisture restrictions. Turgor maintenance plays an important role in drought tolerance of plants which may be due to its involvement in stomatal
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The effect of temperature and drought stress on Bambara groundnut (Vigna subterranea (L.) Verdc) landraces

The effect of temperature and drought stress on Bambara groundnut (Vigna subterranea (L.) Verdc) landraces

9 2.4 Transpiration (T) To carry out photosynthesis, plants must absorb CO 2 from the atmosphere through stomata, while losing water through the same pores. Leaves absorb energy from the sun for photosynthesis, 1% of this energy is used for photosynthesis the rest tends to heat the leaves. Plants usually dissipate the excess energy by transpiration, convection or radiation to prevent the increase of leaf temperature (Azam-Ali and Squire, 2002). Transpiration rate from most dry land crops is usually more limited by resistance from vegetation than the atmosphere. The vegetation effect on transpiration rate can be divided into two categories: the movement of water vapour from the sub-stomatal cavities of leaves to the air above the canopy, which is determined by the physiology and structure of the canopy, and the supply of water from the soil to the conducting vessels in the plant (Squire, 1990). In a study on bambara groundnut, seasonal transpiration of Dip C was 241mm in the irrigated treatments and 168mm in the droughted treatment (Mwale et al., 2007b)
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