Principal component analysis and comprehensive evaluation on drought tolerance difference of canola cultivars at germination and emergence stages

Abstract

Drought stress in autumn is an important factor restricting canola (Brassica napus L.) germination and emergence in the Yangtze River basin in China. Screening drought tolerance varieties in canola is a cost-effective and practical way. The objective of this study was to explore the methods of drought tolerance evaluation and to screen canola varieties with drought tolerance at germination and emergence stages. The experiments were conducted with 53 cultivars under drought treatment and non-stress control. In this research, 16 investigated indicators were synthesized into six independent indices which could represent 87.5% characters information related to drought resistance of canola varieties. With this analysis and evaluation, 53 varieties could be classified into three categories: five varieties as YY10, JLYT, LY9, ZS11, and YY50 owned drought-resistant; 16 varieties as ZY589, QZ7 and DAZ600 and so on, were moderately drought-resistant; and the other 32 varieties belonged to non-drought-resistant. The study proved that there were six indices as mean germination time, germination index, seedling emergence time, fresh and dry weight per plant and 1000-grains weight, which could be used as identifying indicators related to crop drought resistance at germination and seedling stage.