外源硅对不同砧木嫁接黄瓜果面蜡粉和硅吸收及相关基因表达的影响

为探明砧木影响嫁接黄瓜果面蜡粉形成的机制以及与外源硅的关系,以‘山农5号’黄瓜为接穗,‘云南黑籽南瓜’(去蜡粉能力弱)和‘黄诚根2号’南瓜(去蜡粉能力强)为砧木进行嫁接,采用水培法,研究营养液中添加硅与否对黄瓜硅吸收、硅转运蛋白相关基因表达和果实表面蜡粉形成的影响。结果表明:加硅显著提高了‘云南黑籽南瓜’嫁接黄瓜和自根黄瓜果面蜡粉量及各器官硅含量,但加硅后‘黄诚根2号’嫁接黄瓜的果面蜡粉量和各器官硅含量均较低,与不加硅条件下的嫁接和自根黄瓜相近;加硅处理后‘云南黑籽南瓜’嫁接黄瓜苗根系中硅转运蛋白基因Cm Lsi1、Cm Lsi2-1、Cm Lsi2-2和Cm Lsi3的表达量均高于‘黄诚根2号’嫁接黄瓜苗;随着硅处理时间延长,‘云南黑籽南瓜’嫁接黄瓜苗根系中硅转运蛋白基因表达下调,而‘黄诚根2号’嫁接黄瓜苗根系中硅转运蛋白基因的表达同样下调。

Effects of Silicon Nutrition and Rootstocks on Silicon Uptake and Distribution and Expression of Silicon Transporter Genes in Grafted Cucumbers

In order to investigate the mechanism underlying the effects of rootstocks on fruit bloom formation of grafted cucumbers under different silicon nutrition conditions，the rootstocks‘Yunnan figleaf gourd’and‘Huangchenggen 2’were used to study the absorption and distribution of silicon，expression of silicon transporter genes and bloom formation in the grafted plants of cucumber‘Shannong 5’，which were grown by hydroponics with the nutrient solution with silicon added or without. The results showed that the fruit bloom and silicon contents in organ of the cucumbers grafted on‘Yunnan figleaf gourd’and self-rooted cucumbers were significantly increased by added silicon，and much higher than those in the cucumbers grafted on‘Huangchenggen 2’. The fruit bloom and silicon contents in organs of the cucumbers grafted on‘Huangchenggen 2’by added silicon were similar with those of the cucumbers grafted or self-rooted cucumbers in the condition without silicon added. The expression of CmLsi1，CmLsi2-1，CmLsi2-2 and CmLsi3 in roots of cucumbers grafted on‘Yunnan figleaf gourd’was higher than that in roots of cucumbers grafted on‘Huangchenggen 2’. With the prolongation of silicon treatment，the expression of silicon transporter genes in roots of cucumbers grafted onto‘Yunnan figleaf gourd’was down-regulated，the expression of those genes in roots of cucumbers grafted on‘Huangchenggen 2’also decreased.