Document Type : Original Article

Authors

1 Msc. graduate student of plant breeding of college of Aburaihan, University of Tehran, Pakdasht, Iran

2 PhD, Department of Agronomy and Plant Breeding Sciences, college of Aburaihan, University of Tehran, Pakdasht, Iran

3 PhD, department of agronomy and plant breeding, college of agriculture, University of Birjand, Birjand, Iran

4 PhD, Pakdasht, Aburaihan Campous, Department of Agronomy sciences and Plant Breeding, Tehran, Iran

Abstract

In Iran where main part of precipitation takes place during winter and spring, wheat is dependent on water conserved in the sub soil especially at dryland farming systems. In order to identify the genotypes with suitable root system development at sub soil depths, an experiment was conducted with 63 bread wheat genotypes planted in PVC tubes under non stress and drought stress conditions. Under non-stress condition irrigation was conducted regularly, while under stress condition it was delayed until soil moisture was depleted to 30 percent of field capacity. After applying stress and at the end of growth season, root related traits in four depths (0-20, 20-40, 40-60 and 60-100 cm) along with morphological traits, yield and its components were measured. The results showed great variations among genotypes for all studied traits. Highly significant correlations were observed between total root weights and yield under stress conditions (r=0.58, p=0.01). Under these conditions, a unit increase in root dry weight resulted in a 0.24 g increase in grain yield of each plant. Separate correlation analysis for each depth showed that the effect of root dry weight on yield at the deepest depth was higher than other profiles (r=0.75, p=0.01). Under stress conditions, the effect of root weight on yield at 60-100 cm depth was positive and highly significant. Genotypes of Sardari, Sholeh, Naz and Inia were the best genotypes considering root dry weight at this profile with 0.44, 0.39, 0.37 and 0.37 g.plant-1, respectively.

Keywords