Abstract:

In order to understand the salt tolerance of different genotypes of upland cotton germplasm resources, this study subjected 40 samples to salt stress using NaCl solutions with concentrations of 0, 50, 100, 150, 200, and 300 mmol/L, and measured relevant indicators during the seed germination period. Principal component analysis and membership function analysis were used to comprehensively evaluate the salt tolerance of seeds during germination. The results showed that (1) under the stress of high concentration NaCl solution, germination potential, germination rate, hypocotyl length, root length and fresh matter mass per plant all showed a downward trend. (2) Correlation analysis, principal component analysis and membership function comprehensive evaluation were performed on 30 materials with germination rate >50% at A4 concentration, four materials with strong salt tolerance were obtained, namely ‘Han 8266’, ‘Rihui Mian 6’, ‘Zhong R971708’ and ‘Kuaiyu 2’. (3) Through cluster analysis, at the Euclidean distance of 5, the 30 materials could be divided into 3 categories. There were 1 salt-tolerant material in Category I, 18 moderately salt-tolerant materials in Category II, and 11 salt-sensitive materials in Category III.

Key words: upland cotton, seeds, salt stress, principal component analysis, membership function, cluster analysis, germplasm resources, NaCl solution