Evaluation of Drought Tolerance in Rapeseed Genotypes under Non Stress and Drought Stress Conditions

Abstract

Drought is a wide spread problem seriously influencing rapeseed (Brassica napus L.) production, mostly in dryland regions. This study was conducted to determine drought tolerance genotypes with superiority in different stressed environments. Twenty three rapeseed genotypes were tested in a split plot design based on randomized complete block design (RCBD) with four replications in two years (2008- 2009 and 2009-2010) at Seed and Plant Improvement Institute of Karaj, Iran. Seven drought resistance indices include susceptible stress index (SSI), tolerance index (TOL), stress mean productivity (MP), geometric mean productivity (GMP), stress tolerance index (STI), yield index (YI) and yield stability index (YSI) were applied on the basis of seed yield in non stress and drought stress conditions. Based on different drought indices, genotypes ‘Modena’, ‘Geronimo’, ‘Elite’, ‘Syn-4’ and ‘SLM046’ had the best rank with low standard deviation. The results indicated that they have stable yield performance. Bi-plot display and cluster analysis cleared superiority of these genotypes in both years. The synthetic derived cultivars could perform well across all environments with better agronomic performance. Results showed MP, GMP and YI indices were more effective in identifying high yielding cultivars in diverse water scarcity.