Determination of response to drought stress of wild type chickpea genotypes

It is an inevitable that increasing drought stress caused by climate change, will limit the production areas of chickpea. The development of drought tolerance chickpeas varieties is of great importance in terms of the continuation of food security in Turkey. In order to reach breedings goals, a starting material with a wide genetic diversity must be available. In this study, it was aimed to screen wild chickpea genotypes for physiological measurements related to transpiration to enhance the genetic diversity which is narrowed in cultivated chickpea by classical breeding affords. In this study we used 20 C. reticulatum, 6 C. echinospermum wild species which is collected from Southeastern Anatolia Region and for control purposes 4 cultivated chickpea genotypes. In order to demonstrate the differences in transpiration, two different trials which are a) atmospheric vapor pressure deficient (VPD) and b) drydown experiments were carried out. In the VPD study, leaf area and transpiration rate were measured during vegetative and generative growth periods with increasing temperature and decreasing humidity conditions. In the drydown experiments, the plants were exposed to gradual water stress, in the first year starting immediately before the beginning of flowering and the second year of the pod filling period. Based on the daily amount of transpiration measurement the Fraction Transpirable Soil Water (FTSW), Normalisation Transpiration Rate (NTR), Transpiration Efficiency (TE) were calculated and the values of stem weight, grain weight, biomass and harvest index were determined. It has been found that the leaf area of cultivar varieties is higher than the wild genotypes in both years and both periods and that the rate of increase of leaf area till from vegetative period to generative period is 3 times higher in wild genotypes compare to cultivars. In terms of the transpiration rate measured under increasing VPD condition it has been determined that cultivar varieties have lower transpiration rates in both years and both periods and that the rate of transpiration continues with a linear increase in all genotypes without breakpoints. In the drydown experiment, it has been determined that there are wild genotypes that have early inhibition of transpiration in terms of FTSW values and have higher values than culture genotypes. It has been determined that there is a significant difference between genotypes in terms of stem weight, grain weight, biomass and harvest index values in both well water and water stress conditions. In water stress conditions, wild genotypes have high harvest index in both years and high grain number in the second year and this findings shows that their ability of grain production under stressful conditions is high. TE differences were found between genotypes Under well water and water stress conditions, and it was found that some wild genotypes were superior than cultivars in well water conditions. When the wild chickpea genotypes were evaluated for response to VPD stress based on transpitation traits, it was predicted that Şirnak 060, Savur 063, Derei 072 and Besev 075 genotypes of C.reticulatum species and Karab 092 and Ortan-066 genotypes of C.echinospermum species are süperior and could be used as starting material in breeding studies.