不同砧木嫁接对西瓜抗生理性凋萎症的作用机理研究

Effect mechanisms of different grafting rootstocks on physiological wilt disease of watermelon

【目的】探明不同砧木嫁接对西瓜抗生理性凋萎症的作用机理,为抗性砧木筛选和育种提供理论依据。【方法】选用葫芦、南瓜、冬瓜、野生西瓜等12个砧木与广西三号无籽西瓜进行嫁接试验、田间栽培试验,测定不同嫁接组合对西瓜生长后期叶片生理生化指标的影响。【结果】不同的嫁接组合中,以白籽南瓜、广西本地葫芦、杂交葫芦、伙伴野生西瓜、日本南瓜、大蒲瓜、超丰F1作砧木西瓜生理性凋萎症发病率较低,为0～6.00%,最低的为白籽南瓜。发病率低的组合,其叶片叶绿素a、叶绿素b、总叶绿素含量和POD活性、SOD活性、Pro含量均极显著高于对照,MDA含量则显著低于对照。【结论】日本南瓜、广西本地葫芦、杂交葫芦、伙伴野生西瓜对西瓜生理性凋萎症抗性较强,可在生产上示范应用。

[Objective]The experiment was conducted to study the effect mechanisms of different rootstocks on physiologi- cal wilt disease of watermelon in order to provide theoretical foundation for resistant rootstock screening and watermelon breeding. [Method]Twelve different rootstocks of Lagenaria siceran＇a, squash, Benincasa and wild Citrullus vulgaris were se- lected to undergo the grafting test and filed cultivation test with seedless watermelon Guangxi 3. Physiological and biochemical indexes of watermelon leaves of different grafting combinations at later stage were determined. [Result]The watermelon grafted with rootstocks of white seed pumpkin, Guangxi local eucurbit, cross cueurbit, Huoban wild watermelon, Japanese pumpkin, large white flowered gourd, and Chaofeng F1 generation showed low incidence rate of physiological wilt disease. The incidence rate was in 0-6.00%. The incidence rate of physiological wilt disease was the lowest when white seed pumpkin was used as root- stock. The chlorophyll a content, chlorophyll b content, total chlorophyll content, POD and SOD activity and free praline con- tent were all significantly higher than the control, while the MDA content was significantly lower than the control. [Conclu- sion]Four rootstocks viz., white seed pumpkin, Guangxi local cueurbit, cross eueurbit, Huoban wild watermelon showed stronger resistance to physiological wilt disease, therefore they could be applied to watermelon production.