ارزيابي لاين هاي اينبرد ذرت براي تحمل به خشكي بر اساس شاخص هاي مقاومت و روش باي پلات

An Evaluation of Maize Inbred Lines for Drought Tolerance Based on Resistance Indices and Biplot Method

To determine the most desirable index for drought tolerance and for B detection of tolerant genotypes under restricted irrigation, among 25 inbred lines, an experiment was conducted in field conditions, using a randomized complete block design of three replications under three irrigation regimes of: fun irrigation and restricted irrigation (during vegetative and reproductive growth stages), in 2003. Rased on the genotypes, performance in the two irrigation regimes (i.c. complete and restricted irrigation), different indices including mean productivity (MP), geometric mean productivity (GMP), stress susceptibility index (SSl), stress tolerance (TOL) and stress tolerance index (STI), were eveluated. Correlation coefficients between these indices and between yield indieated that MP, GMP and STY indices were the desirable ones and based on these, the most tolerant genotypes were pointed out to 25, 5, 19, 8, 12, 14,3 and 1. in restricted irrigation in reproductive stage GMP and STI indices were the most desirable ones based upon which the most suitable genotypes were found as:25, 5, Il, and 9. Using biplot method for a determination of tolerant genotypes itwas shown that in restricted irrigation in vegetative stage the 8 inbred Jines of 25,5,19,8.12,14,3 and I, and in restricted irrigation in reproductive stagefive inbred tines of25, 5, 8, 9 and 6 were located in the part of highyield potential along with low sensitivity to drought. Therefore, it isshown that selection for drought tolerance among inbred lines is possible. According to these results, one can selectlines with high production potential and low sensitivity to drought and toemploy them forproduction oftolerant hybrids.