Response of different wheat genotypes to drought and heat stresses during grain filling stage

Document Type : Original Article

Authors

1 Biotechnology Lab, Department of Crop Science, Faculty of Agriculture, El Shatby, Alexandria University, Alexandria, Egypt.

2 assistant professor - Faculty of Desert and Environmental Agriculture- Alexandria University - Matrouh Branch

3 Department of Genetics, Faculty of Agriculture, El Shatby, Alexandria University, Alexandria, Egypt

4 Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA

Abstract

The present study was carried out to study the performance of durum and bread wheat genotypes in relation to grain filling process, under water and heat stresses. The experiment was laid out in split plot design with three replicates at Fuka Research Station, Faculty of Desert and Environmental Agriculture, Matrouh Governorate (North West Coast of Egypt) in 2011/2012 and 2012/2013 winter seasons. Environmental conditions were considered as the main plots and included four environments (normal, drought, heat, heat and drought conditions). Sub plots were assigned to fourteen durum and bread wheat genotypes. The results revealed significant variations between studied environments for number of grains per spike (NGS), one-hundred grain weight (HGW) and grain yield (GY). However, number of fertile tiller (NFT) was insignificantly influenced by environments. Wheat varieties significantly differed for the studied four traits, whereas, the environment x variety interaction significantly influenced NFT and GY only in both seasons. Grain yield, as an average of the two seasons, was reduced by 26.03, 43.07 and 58.28 percentages at drought, heat and combined drought and heat, respectively, compared to normal conditions. All wheat genotypes suffered with application of combined drought and heat stresses in both seasons. Wheat genotypes varied in their response to heat stress conditions where Beni suef 3 and Sohag 3 (durum wheat) and Sids 1 and Giza 168 (bread wheat) showed comparatively higher tolerance to heat stress. In addition, stability analysis revealed a differential response of wheat varieties (b value) to individual or combined drought and heat stress.

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