Abstract:

To screen out new pakchoi varieties suitable for cultivation in clubroot affected areas of Chengdu Plain，we conducted a comparative trial by using 87 pakchoi varieties, investigated agronomic traits, clubroot resistance, and yield-related characteristics. A comprehensive evaluation was performed by using principal component analysis (PCA) combined with the membership function method. The results showed that PCA of 14 indicators extracted 4 principal components (PCs), with a cumulative contribution rate of 82.874%. PC1 was primarily correlated with plant weight, head diameter, petiole width, waist diameter, petiole thickness, and yield. PC2 showed strong correlations with leaf length, petiole length, plant height, and plant width. PC3 was closely associated with the incidence of clubroot and clubroot disease index. PC4 was mainly correlated with leaf width and rosette leaf number. Based on standardized data of various traits and the corresponding eigenvectors, the comprehensive indicator values for 4 PCs were calculated. Subsequently, the membership function value and weight of each PC and comprehensive evaluation D value of each variety were derived. The D values of the 87 varieties ranged from 0.307 to 0.833, with higher D values indicating better overall performance. In conclusion, the top 3 varieties in the comprehensive ranking were ‘Xia Shang Wei No. 2’, ‘Xia Wei Pakchoi’, and ‘Chun Shang Wei’, all of which were suitable for cultivation in clubroot-affected areas of Chengdu Plain. Notably, ‘Xia Shang Wei No. 2’ and ‘Xia Wei Pakchoi’ exhibited immunity to clubroot, and ‘Zi Guan Jiao Zi’ ranked the last in the overall ranking.

Key words: pakchoi, variety, comprehensive evaluation, principal component analysis, membership function method, clubroot