Vat抗性甜瓜研究进展

Advance of Study on Melon (C.melo L.) with Resistant Gene Vat (Virus aphid transmission)

Vat(Virus aphid transmission)是指对棉蚜(Aphis gossypii Glover)取食和对棉蚜传播CMV都有一定抗性的基因。到目前为止,已在数种甜瓜(Cucumis melo L.)的种质中发现了抗性物质,被提出的抗性基因有PI371795、PI161375、PI255478、PI414723等(其中PI414723来源于PI371795)。其中对其抗性具有清楚描述的是来自印度的PI414723和来自韩国的PI 161375两大种系。Vat的抗性包括抗蚜虫和抗蚜传病毒两方面,目前认为这两种抗性具有不同的机制。Vat对蚜虫的抗性可能与蚜虫的取食行为无关,而是化学因子的作用。Vat植物可能通过调控韧皮部汁液中的氨基酸的含量使其聚合成肽形成抗氧化剂来增强对蚜虫的抗性。而Vat对蚜传病毒的抗性则可能是由于Vat植物体内的氧化还原电位高于蚜虫体内的氧化还原电位,使得蚜虫口针末端暂时堵塞,使蚜虫无法分泌唾液而无法传毒。有关Vat抗性的机制还在继续讨论。

Vat means the genes that are resistant to both feeding behavior of Aphis gossypii and CMV transmission conferred by Aphis gossypii. By far, resistant substances have been found in several sources of Cucumis melo L. and resisitant genes including PI 371795, PI 161375, PI 255478, PI 414723 and so on have been put forward . PI 371795, a momordica vartiey from India, from which PI 414723 was derived, and PI 161375 , a chinensis vartiey from Korea have been identified in these sources. The resistance of Vat includes two aspects that are resistance to aphids and virus tranmission conferred by aphids, and people think that their (mechanisms) are different by far. Vat resistance to aphids maybe has something to do with chemical factors instead of feeding behavior of aphids. Vat plants may control the concentration of some amino acids in phloem sap and make them to polymerize to peptides which form the antioxidant to enhance resistance to aphids. On the other hand, the resistance to virus transmission conferred by (aphids) may be due to body’s redox potential of plants and aphids. If the redox potential of plants is higher than that of aphids, it will lead to temporary blockage of stylet tips of aphids and aphids can’t salivate to inoculate. The mechanism of Vat resistance is (discussed).