Response of contrasting bread wheat genotypes for heat and drought stress tolerance for rhizospheric soil properties

Abstract

Aim: The study aimed at investigating differential response of contrasting bread wheat genotypes for heat and drought stress towards changes in chemical and microbial components of rhizospheric soil for developing climate resilient wheat varieties. Methodology: Rhizospheric soils were studied for changes in pH, electrical conductivity, cations, anions, micro-elements, major-elements, organic carbon and organic matter, and plant growth promoting rhizobacteria(PGPRs) abundance at booting and anthesis stages of growth in four contrasting genotypes during 2017-18 and 2018-19 crop seasons Results: The contrasting genotypes (HD2967 and WH730) for heat tolerance exhibited significant interaction between genotype and stage of growth for Na+, K+ and nitrogen, while genotypes (HUW468 and C306) for drought tolerance exhibited it for available nitrogen only. Significant difference for Ca2+, Mg2+, iron, manganese, nitrogen and potassium levels were recorded in drought stress related genotypes at two stages of growth. The heat tolerant genotype showed 2.54 and 10.67 folds enhancement in population of N2 fixing and spore forming bacteria at anthesis compared to sensitive genotypes, while drought tolerant genotype showed 1.51, 1.07 and 6.26 folds in P-solubilizing, N2 fixing and general bacterial abundance. Interpretation: Contrasting genotypes for heat and drought stresses responded differently for chemical properties and abundance of PGPRs in rhizospheric soils.