香蕉枯萎镰刀菌致病性快速测定方法的建立

A Rapid Method for in vitro Pathogenicity Test of Fusarium oxysporum f. sp.cubense

建立致病性变异突变体库是研究香蕉枯萎镰刀菌致病机理的有效方法,此方法需要对大量突变体进行致病性测定,经典的根部接种测定方法耗时长达40 d,工作量十分巨大。因此,建立一种简便快速的致病性测定方法是高效建立香蕉枯萎病菌致病性变异突变体库的关键。本研究以香蕉巴西蕉和粉蕉叶片为材料,采用香蕉离体叶片分别接种香蕉枯萎病菌1号小种、4号小种、致病性丧失突变体、致病性严重减弱突变体,分别置于20℃、25℃、30℃、35℃、37℃条件下进行保湿培养3 d、5 d、7 d,观察发病情况,测定病斑大小。并通过根部接种法对离体叶片接种法的结果进行验证。结果表明,离体叶片测定法和根部接种法测定的结果一致,最佳致病温度30℃。从而建立了一种简便快速的香蕉枯萎病突变体致病性测定方法(离体叶片接种法)。运用该法在适宜的条件下可以准确、可靠、快速和简便测出香蕉枯萎病菌致病性,大大提高了突变体致病性测定筛选的效率。

It is an effective method to establish pathogenicity variation mutant library for studying the pathogenic mechanism of Banana Fusarium wilt. This method requires huge workload to test pathogenicity of a large number of mutants, it needs to consume 40 days more by using classical root inoculation determination method. Therefore, to establish a simple and rapid method for determining pathogenicity is the key to efficient develop pathogenic mutants library of Banana Fusarium wilt. It this study, the vitro leaves of both banana cultivar‘Brazilian＇and‘Pisang awka＇were inoculated with Focr1（race 1）, Focr4（race 4）, mutant with no pathogenicity and mutant with significant pathogenicity reduction and cultured at 20℃, 25℃, 30℃, 35℃ and 37℃ for 3 d, 5 d and 7 d under moisture condition, observed incidence and measured lesion size. Also, this was verified by roots inoculation. The result showed that both detection result were identical and the most suitable pathogenic temperature was 30℃. Therefore,establishing a simple and rapid pathogenicity determination method of Fusarium oxysporum f. sp. cubense. The vitro leaves inoculation is considered as a simple and rapid detection method. Pathogenicity of Fusarium oxysporum f. sp.cubense is accurately, reliably, rapidly and simple detected through the method, which highly improves the screening efficiencyof mutant pathogenicity determination.