Grey Decision and Cluster Analysis on Heat Resistance of Different Cabbage Genotypes

A total of 11 traits, including 4 agronomical traits and 7 physi-biochemical traits that measured in 12 cabbage genotypes under high temperature stress, were analyzed using gray decision and cluster analysis method. The results of gray correlative analysis showed that the index were ranked according to their gray correlation degree to seedling index as follows: GSH content,SOD activity, POD actitvity, plant weight, dry weight of above-ground/dry weight of under-ground,MDA content,Vc content,relative membrane permeability, Pro content and fresh weight of above-ground / fresh weight of under-ground. The comprehensive measure values of Qiangxia-1-2 was 1.465 1, has greatest integrated performance, followed by Kangre50-1. The comprehensive measure value of 77-2 was 1.217 3, has the poorest performance. Cluster analysis showed that 12 situ accessions were classified into 3 categories. The first category was the most heat resistance situ accessions including Qiangxia-1-2, Kangre50-1 , Zhonggan17-2 and 118-1, the second category was the intermediate heat resistance situ accessions including ZaohengzhuQiulv, Qiulv-1, 97-4 and Zaohengzhu97-4, and the third category was the sensitive to heat stress situ accessions including 135-4-1 , Zhonggan16-3, 106-H and 77-2.