Differential responses of BA injection on yield and specific grain growth in contrasting genotypes of wheat (Triticum aestivum L.)

The effect of exogenous cytokinin ( benzyladenine) was investigated on location specific grains in three contrasting wheat genotypes tolerant or susceptible to post anthesis high temperature conditions. Seeds were sown in earthen pots under natural environment in November and January for normal and late sowings, respectively. Grain weight was increased by the application of benzyladenine at anthesis under late sown stress only in those genotypes, which are known, to posses temperature tolerance in developing grains. However, under normal sowing conditions BA application was effective irrespective of genotype response to late sown stress. The effect was most visible in distal spikelets in the spike and distal grains in the spikelet which resulted in higher increment in weight of younger grains ( c and d) as compared to older grains ( a and b). It has been suggested that the responsiveness of the genotype to BA application under late sown stress is important and may be developed as an indicator to screen wheat genotypes for relative tolerance to late sown stress under irrigated conditions.