硅营养和嫁接砧木对黄瓜幼苗耐冷性的影响

Effects of Silicon Nutrition and Grafting Rootstocks on Chilling Tolerance of Cucumber Seedlings

以‘新泰密刺’黄瓜(Cucumis sativus L.)自根幼苗、砧木品种‘黄诚根2号’(Cucurbita moschata Duch)和砧木品种‘云南黑籽南瓜’(Cucurbita ficifolia Bouché)嫁接幼苗为试材,通过水培试验研究了硅营养和砧木类型对黄瓜幼苗耐冷性的影响。结果表明:低温胁迫下,加硅处理的自根黄瓜幼苗冷害指数显著低于不加硅处理;无论是否加硅,嫁接黄瓜的冷害指数均低于自根黄瓜,以‘云南黑籽南瓜’嫁接黄瓜的耐冷性最强;硅营养和嫁接砧木均降低了黄瓜叶片的电解质渗漏率和丙二醛(MDA)含量,增加了脯氨酸(Pro)含量,提高了SOD、POD和CAT活性,嫁接砧木的作用大于硅营养,‘云南黑籽南瓜’的作用大于‘黄诚根2号’。综上,硅营养和嫁接砧木均影响黄瓜幼苗的耐冷性,但以砧木的作用更明显,砧木‘云南黑籽南瓜’作用大于砧木‘黄诚根2号’。

In this study,effects of silicon nutrition and grafting rootstocks on chilling tolerance of‘Xintaimici’cucumber(Cucumis sativus L.)were investigated by using hydroponic non-grafted seedlings and grafted seedlings on both strong de-blooming rootstock‘Huangchenggen 2’(Cucurbita moschata Duch)and weak de-blooming rootstock‘Yunnan Figleaf Gourd’(Cucurbita ficifolia Bouché).The results showed that,under low temperature stress,chilling injury index(CII)of non-grafted cucumber seedlings treated with silicon was significantly lower than that without silicon.The lowest CII was observed in grafted cucumber seedlings on‘Yunnan Figleaf Gourd’followed by the grafted ones on‘Huangchenggen 2’and finally the non-grafted ones,regardless of silicon supplementation.The significant reduction in electrolyte leakage rate and malondialdehyde content,and the significant enhancement in proline content and antioxidant enzyme(SOD,POD and CAT)activities were observed in the leaves of seedlings supplemented with silicon relative to those without silicon,and in the leaves of grafted seedlings relative to the non-grafted ones,and the alterations in these tolerance-related parameters were greater for grafting treatment,in particular‘Yunnan Figleaf Gourd’used as rootstock,than silicon supplementation.Altogether,our study revealed that both rootstocks and silicon nutrition can improve the chilling tolerance of cucumber seedlings,while grafting treatment displays better performance than silicon supplementation,and for grafting treatment,‘Yunnan Figleaf Gourd’is superior to‘Huangchenggen 2’in alleviating the detrimental effects of chilling stress on cucumber seedlings.