Studies on Heat Tolerance Identification Method for Non-heading Chinese Cabbage〔Brassica campestris L. ssp. Chinensis（L.）Makino var. communis Tsen et Lee〕
HU Qiao-qiang1, 2, CHEN Long-zheng2, ZHANG Yong-ji1, 2, XU Hai2, SONG Bo2, SU Xiao-jun2, YUAN Xi-han2*
1State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China; 2Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, China
Abstract：Ten non-heading Chinese cabbages〔Brassica campestris L. ssp. chinensis（L.）Makino var. communis Tsen et Lee〕materials were continuously treated with 6 different high temperatures for 7 days in artificial climate box in spring, autumn and summer, in order to identified their heat tolerance. The results indicated that under different heat stress, different degrees heat injure symptoms such as leaf back-scrolling, chlorosis, appeared in all tested materials，and these symptoms became severe along with temperature increasing and treatment time prolonging. The heat injure symptoms could be intensified. The heat injury index at seedling stage by heat treatment of 37 ℃/27 ℃（d/n）for 4 days in spring and autumn could significantly reflect the differences in heat tolerance of different non-heading Chinese cabbage varieties. While in summer, culturing seedling with nature temperature under 37 ℃/27 ℃（d/n）could not significantly distinguish the differences in heat tolerance of different non-heading Chinese cabbage varieties.
