普通白菜苗期耐热性鉴定方法研究

采用人工气候箱高温处理方法，分别于春、秋和夏季，在6种不同的高温条件下对10份普通白菜材料进行连续7 d的高温处理研究其耐热性。结果表明，在不同的高温胁迫下，各供试材料均会出现不同程度的热害症状，如叶片反卷、失绿等，并随着温度的升高和处理时间的延长，热害症状加剧。以春季和秋季采用37 ℃/27 ℃（昼/夜）处理幼苗4 d后调查其热害指数，可以显著反映出普通白菜各品种间的耐热性差异。而夏季采用自然温度育苗后在37 ℃/27 ℃（昼/夜）下不能显著区分普通白菜各品种间耐热性差异。

Studies on Heat Tolerance Identification Method for Non-heading Chinese Cabbage〔Brassica campestris L. ssp. Chinensis（L.）Makino var. communis Tsen et Lee〕

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.