脯氨酸对高温胁迫下菜薹耐热性的影响

以50天油青菜心为试材，研究了不同浓度脯氨酸处理对菜薹苗期及田间耐热性的影响。苗期试验结果表明，随着高温胁迫时间的延长，菜薹幼苗的热害指数、电解质渗透率不断增高，高温胁迫8～12 h，脯氨酸浓度在150～200 mg•L-1处理的热害指数、电解质渗透率降幅明显，超氧化物歧化酶、过氧化物酶活性增幅明显|田间试验结果表明，脯氨酸浓度在150～200 mg•L-1处理可明显促进叶片生长，增加叶面积、薹鲜质量和根鲜质量，以及提高可溶性糖、可溶性蛋白和VC含量。结果表明脯氨酸能增强菜薹的抗氧化能力和维持渗透调节能力，从而缓解高温胁迫对菜薹的伤害。

Effect of Proline on Heat Tolerance of Brassica campestris L.ssp.chinensis var.utilis Tsen et Lee under High Temperature Stress

Effects of different proline concentrations on heat tolerance of ‘50 tianyouqingcaixin’（Brassica campestris L．ssp．chinensis var．utilis Tsen et Lee）during seedling period and in fields were studied．The result of seedling experiment showed that the heat injury index，leakage of electrolyte in leaves of flower stalk increased continuousely along with the prolonging of high temperature stress．With the treatment of Pro concentration in 150-200 mg•L-1 under 8-12 h high temperature stress，the heat injury index and leakage of electrolyte were reduced obviously．The SOD and POD activities were increased obviously．The result of field experiment showed that the treatment of Pro in 150-200 mg•L-1 could obviously promote the leaf growth，increase leaf area，improve flower stem and root weights，and enhance the contents of soluble sugar，soluble protein and VC．All these results indicated that proline could relieve flower stalk damage by boosting antioxidant activity and maintaining osmotic adjustment ability under high temperature stress．