香蕉品种对枯萎病菌感病性与对病菌毒素敏感性之间的相关性

Correlation between susceptibility of pathogen and crude toxin of Fusarium oxysporum f. sp. cubense race 4 in banana cultivars plantlets

为明确香蕉品种对香蕉枯萎病菌感病性与对病菌粗毒素敏感性之间的相关性,采用根部病菌孢子接种测定了36份香蕉品种苗对香蕉枯萎病菌4号生理小种的感病性,以及采用植株根部和叶片毒素处理测定了5份香蕉品种苗对病菌粗毒素的敏感性。结果表明,天宝角蕉(AAA)、柴蕉(AAA)、广粉1号(AAB)和贡蕉(AA)表现抗病,哥斯达黎加蕉(AAA)和抗枯5号(AAA)表现中抗;感病品种对毒素的敏感性高于抗病品种。通过香蕉不同品种的病情指数、萎蔫指数和叶片损伤面积的差别分析,发现香蕉苗期对枯萎病菌感病性与对病菌粗毒素敏感性之间存在正相关性,60d龄期的假植苗病情指数与其叶片损伤面积之间存在显著的正相关性。因而叶片毒素处理法测量香蕉假植苗中部叶片损伤面积可作为一种快速区别香蕉抗病能力的有效方法。

A study was done to investigate the correlation between susceptibility for Fusarium oxysporum f. sp. cubense （Foc） race 4 and susceptibility for crude toxins of the pathogen in banana cultivars. The susceptibility of 36 banana cultivars to pathogen was studied by inoculating plantlet roots with Foc race 4 conidial suspension. The susceptibility of 5 banana cultivars to crude toxins was studied by treating plantlets roots and leaves with crude toxins of Foc race 4. The results showed that 4 cultivars,namely Tianbaojiaojiao （AAA）,Chaijiao （AAA）,Guangfen1 （AAB） and Gongjiao （AA） showed resistance to Foc race 4,and 2 cultivars,namely Costarica （AAA） and Kangku 5 （AAA） showed intermediate resistance to Foc race 4. The susceptible cultivars showed also higher susceptibility to the crude toxins than the resistant cultivars. Analysis of the difference of disease index,wilt index and leaves lesion area of banana plantlets showed that there is a positive correlation between the susceptibility for the pathogen and crude toxins of Foc race 4 in banana cultivars,and a significant positive correlation between disease index and leaves lesion area of 60-day-old pseudo-planting plantlets （PPP）. Measuring the leaves lesion area in the middle leaves of PPP after treatment with crude toxins for 72 h could thus be used as an effective method to identify the resistance reaction of banana cultivars to Foc race 4.