高温胁迫对苦瓜生理特性影响的分析

Effects of high temperature stress on several physiological traits in Momordica charantia

分析了在高温胁迫下4个在耐热性上具有明显差异的苦瓜材料的若干生理特性,结果表明:连续高温胁迫下几种苦瓜材料的电解质外渗率、丙二醛和脯氨酸含量出现逐渐增加的趋势,而叶绿素含量和光系统II原初光能转化效率(Fv/Fm)出现逐渐下降的趋势,但耐热性强的苦瓜材料叶片的电解质外渗率和丙二醛含量明显低于耐热性弱的苦瓜材料,Fv/Fm值高于耐热性弱的苦瓜材料.高温胁迫下耐热性强和弱的材料中脯氨酸和叶绿素含量未出现明显对应关系,而耐热性强的材料的叶绿素含量的减少量明显低于耐热性弱的材料.因此,这些与耐热性强弱相关的生理特性可以考虑作为评价苦瓜耐热性的生理指标.

High temperature （HT） stress is an important factor to affect the yield and quality of Momordica cha-rantia （ bitter gourd） , monitoring physiological traits at HT stress will be beneficial to understand possible mech-anisms of HT tolerance in bitter gourd. In the current study, certain physiological traits of bitter gourd were ana-lyzed under HT stress with 4 genotypes which contrast in heat tolerance. The result showed that four genotypes of bitter gourd decreased the chlorophyll content and Fv/Fm ratio gradually, and increased the electrolytic leak-age rate, malondialdehyde （MDA） and proline contents gradually with the time of HT stress. Two HT tolerant genotypes were with lower electrolytic leakage rate and MDA content, and higher Fv/Fm ratio in comparison with HT sensitive genotypes under HT stress. The association of HT tolerance was not observed for chlorophyll and proline content at HT stress, but reducing percentage of chlorophyll content was significantly lower in HT toler-ant genotypes than that in HT sensitive genotypes. Therefore these physiological traits associated with heat toler-ance could be considered as indexes for evaluation HT tolerance in bitter gourd.