Abstract

Drought is a major problem reducing agronomic crop production worldwide. Increasing the genetic potential of yield in water deficit condition is one of the major objectives of durum wheat breeding programs in Iran and other countries. This study was conducted to determine drought tolerant genotypes with high yield in normal and drought stress conditions. Twenty-five durum wheat genotypes were tested in a randomized complete block design with three replications under greenhouse condition during 2010 and 2011. Eight drought tolerance indices mean productivity (MP), tolerance index (TOL), geometric mean productivity (GMP), stress susceptibility index (SSI), yield index (YI), harmonic mean (HARM), yield stability index (YSI) and stress tolerance index (STI) were applied on the basis of grain yield in drought stress (Ys) and normal irrigation (Yp) conditions. Based on different drought indices, pol-dash (1) and chakmak genotypes were more drought tolerant than the other genotypes. 3Dgraphs, Bi-plot and cluster analysis confirmed these results. Principal components analysis showed two components which explained 98.0% variation. Genotypes were grouped in cluster analysis (using Ward’s method) based on Yp, Ys and quantitative indices of drought tolerance. Finally, the results of correlation and other analysis showed that the most suitable indices to screen genotypes in drought stress condition were MP, STI, GMP and HARM.

Key words: Landrace, screening, bi-plot, principal component, cluster analysis.

Abbreviation

TOL, Tolerance index; MP, mean productivity; GMP, geometric mean productivity; SSI, stress susceptibility index; YI, yield index; HARM, harmonic mean; YSI, yield stability index; STI, stress tolerance index; Ys, yield in drought stress; Yp, normal irrigation.