Abstract：Taking field screening method，this experiment obtained an extremely cold-tolerant tillering mustard inbred line‘18J380（xiyepaicai）’and large-leave mustard inbred line‘18J381（guangdongkejiajie）’ with poor cold tolerance from over 400 mustard inbred lines．This paper compared and analyzed the different physiological indexes of leaf mustard by climate chamber simulating low temperature treatment at 4 ℃．The result showed that the falling range of‘18J380’relative water content was less than that of‘18J381’．The result was consistent with that of growth form observation．The increasing range of conductivity was less than that of‘18J381’．The ascensional range of malondialdehyde（MDA）content was greater than that of‘18J381’．The falling ranges of the reduction of the PSⅡreaction centres（Fv/Fm），actual PSⅡeffciency（ΦPSⅡ） and photochemical quenching（qP）of PhotosystemⅡwere all less than that of‘18J381’，the value of Non-photochemical quenching（NPQ）increased．The ascensional range of superoxide dismutase（SOD）activity and free proline content was significantly greater than that of‘18J381’．
The above results indicated that the extremely cold-tolerant tillering mustard inbred line‘18J380’could relleve its own stress damage by increasing SOD activity and free proline content，and thus maintained stronger photosynthesis ability under low temperature stress．
王玉贤2 姚培杰1 袁颖辉1 杨文杰1 万正杰1*. 低温胁迫下不同耐寒性叶用芥菜的生理差异分析[J]. 中国蔬菜, 2021, 1(6): 74-79.
WANG Yuxian2，YAO Peijie1，YUAN Yinghui1，YANG Wenjie1，WAN Zhengjie1*. Analysis of Physiological Differences of Leaf Mustard with Different Cold Tolerance under Low Temperature Stress. China Vegetables, 2021, 1(6): 74-79.