Screening of Indian Wheat Genotypes for Tolerance to Drought Conditions and its Correlation to Drebs Transcription Factors

Abstract

Eighteen Indian wheat genotypes were assessed for water stress conditions using morpho physiological and molecular tools. A set of eighteen wheat genotypes were used under normal sown in irrigated condition and no irrigated conditions. Results revealed that postflowering drought stress reduced the grain yield and yield components in all genotypes. The highest yield loss was caused by the number of grain per spike and 1000-grain weight reduction under drought stress conditions. The genotypes UP-2425, WH-1100, PBW-590 showed minimum decline and HD-1080, DBW-17 and WH-1105 showed sharp decline for morpho and physiological as well as yield characters in stress at anthesis. However, low to high reductions were observed in stress conditions as compared to non-stress. The effects of drought stress on wheat genotypes were also analyzed by PCR screening using eight gene specific primers. The OsMSR2 is the only primer showing constitutive, inducible and repressible level of allele expression with all 18 wheat genotypes under control and drought stress condition. Their expression is induced in UP-2744 but their expression is repressed in HD-1080, PDW-621 and PBW-550. TaSHN2 primer showing two strong DNA bands in all18 genotypes but in RAJ-3765 and UP-2744 single bands is present both under control and drought stress conditions. Molecular analysis revealed that all the primers used in the study amplified a DNA approximately 100 bp in drought stress as well as unstressed condition with all 18 genotypes. It is considered as a consensus sequence of these genes with their respective primers which means that there is no genetic diversity in the genotypes where same size band was amplified. This suggests that well adapted cultivars may not differ much in their respective gene sequence. While on the other hand, non amplifying bands in rest of the genotypes indicated that these genotypes might possess entirely different genes which were not picked up by these primers and had more conserved coding region.