根际高温对不同砧木黄瓜嫁接幼苗生长、光合及生理特性的影响

Effects of Rhizosphere High Temperature on Growth, Photosynthesis and Biochemical Indexes of Grafted Cucumber Seedlings on Different Rootstocks

为研究嫁接提高黄瓜耐热性的问题,以黑籽南瓜(Cucurbita ficifolia)、日本南瓜(Cucurbita moschata)、‘甬砧8号’白籽南瓜(Cucurbita maxima×Cucurbita moschata‘Yongzhen No.8’)、‘五叶香’丝瓜(Luffa cylindrica‘Wuyexiang’)和‘傲美’苦瓜(Momordica charantin‘Aomei’)为砧木,‘春秋王2号’黄瓜(Cucumis sativus‘Chunqiuwang No.2’)为接穗,采用营养液栽培法,研究25℃(CK)和35℃根际温度下处理5天及恢复生长5天后不同砧木黄瓜嫁接苗和自根苗的生长、光合及生理特性变化。结果表明,35℃根际高温处理后,不同嫁接苗和自根苗的株高、茎粗、叶片数和叶面积都有所增长,其中‘五叶香’丝瓜砧木嫁接苗生长量最大,且‘五叶香’丝瓜砧木嫁接苗的叶片净光合速率(Pn)、抗氧化酶活性和脯氨酸含量都显著高于其他几种嫁接苗及自根苗,同时,丙二醛(MDA)含量最低。‘五叶香’丝瓜作为砧木嫁接黄瓜能更好地提高其对根际高温的耐受性,为黄瓜的耐热性研究提供理论依据。

This study aims at improving cucumber heat tolerance through grafting. By hydroponic cultivation,the authors took Cucurbita ficifolia, Cucurbita moschata, Cucurbita maxima× Cucurbita moschata‘YongzhenNo.8＇, Luffa cylindrica‘Wuyexiang＇and Momordica charantin‘Aomei＇as rootstocks, and Cucumis sativus‘Chunqiuwang‘No.2＇as scion, to analyze the change of growth, photosynthesis and biochemical indexes ofcucumber seedlings treated by normal temperature（25℃） and high temperature（35℃） in rhizosphere for 5 dand recovered for 5 d. The results showed that grafted cucumber seedlings on different rootstocks had differentplant height, stem diameter, blade number and leaf area under high temperature stress in rhizosphere, theincrement of grafted seedling of Luffa cylindrica‘Wuyexiang＇was the largest, and its leaf net photosyntheticrate（Pn）, antioxidant enzyme activity and proline content were significantly higher than other kinds of graftingseedlings, at the same time, its malondialdehyde（MDA） content was the lowest. It is suggested that Luffa cylindrica‘Wuyexiang＇taken as rootstock for grafting cucumber could improve the tolerance of rhizosphere high temperature, and provide a theoretical basis for studying cucumber heat resistance.