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.
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Received: 06 June 2020
Published: 27 August 2020
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