Evaluation of drought tolerance indices for screening some of super sweet maize

摘要

Drought is the most severe production constraint for maize ( Zea mays L.). The objective of this study is to investigate the efficiency of several drought indices in identifying 24 super sweet maize inbred lines combining drought tolerance and high yield potential. The experiment was laid out as completely randomized block design of 4 replications. Twenty indices, were compared based on grain yield, under two environments (Non-Stressed and Drought-Stress condition) during 2018 growing season. All drought indices revealed significant differences among inbred lines, except GM. Results in ranking method, indicate that among drought tolerance indices, MP, GMP, STI, HARM, MRP, REI and RDY are most suitable indicators because of highest correlation with grain yield under both conditions and also positive correlation together. Cluster analysis and Three dimensional plots, showed inbred lines with highest tolerance to drought, in both conditions. First three principle components (PCs), explained 96.34 percent of total variation and the PC1 can be nominated as potentially stable yield. The Biplot diagram based on PCs and drought tolerance indices showed that MP, GMP, STI, HARM, MRP, REI, MSTIK1, MSTIK2 and YI were the best indices for screening tolerant inbred lines such as MCH87002/19-1, MPA90010/51-1 and MSH90011/82-1.