Identification of New Genetic Resources Under Drought Stress in Response to Roots and Nodules in chickpea

Abstract

Ten high nodulation and two poor nodulation chickpea genotypes were selected from the previous field experiment to study the effect of drought stress on various nodules, root characteristics, and physiological traits of chickpea. The experiment was conducted under greenhouse conditions as a split factorial plot design with two replications. The main plot (spilt) included two levels of water stress: well-watered and severe stress. The factorial plot included genotypes and three treatments: a combination of two rhizobia strains (ICARDA36, NIF1148), ammonium nitrate, and a control. The result indicated that drought stress had a significant effect on nodule biomass (NB), nodule dry weight (NDW), root biomass (RB), root dry weight (RDW), chlorophyll content (Chl), relative water content (RWC), stomatal conductance (gs), grain yield (GY), 100 seed weight (100SW), and pod number (PN), but was not significant in the number of empty pods (EPN). In general, inoculation by Rhizobia strains increased the value of all the studied parameters under both water treatments. The highest regression relationship between grain yield and root biomass, 100 seed weight was found in rhizobia treatments (R2=0.60, 0,74) respectively. The four genotypes (Genesis090, IG13032, IG70270, IG70272) produced the highest nodules, root biomass, and yield under drought conditions. This result will help the breeders to develop new chickpea varieties with better nodulation under drought conditions.