新疆野果林疫霉菌对植物叶片致病性的测定与分析

Leaf Pathogenicity of Phytophthora in Wild Fruit Forest of Xinjiang

[目的]从病原菌和寄主两个维度,探究新疆野果林中疫霉菌对野果林内主要树种叶片的致病性,了解新疆野果林衰退的可能原因及疫霉对新疆野果林造成的潜在风险。[方法]利用菌丝块接种离体叶片的方法,将诱捕自新疆野果林的5种疫霉(Phytophthora plurivora、P.gonapodyides、P.lacustris、P.gregate、P. sp.)接种到苹果、杏、山楂和核桃的健康离体叶片上,一周后观察测量、计算病斑大小,并用R软件对数据进行双因素方差分析和作图。[结果]实验结果及数据分析表明:供试5种疫霉菌株接种到4种植物叶片上后,病斑大小存在显著性差异。其中,P.plurivora和P.lacustris产生的病斑较大,最大分别为18.68 cm^2和14.14 cm^2;寄主植物中,核桃和杏树叶片产生病斑较大,最大分别为18.68 cm^2和9.55 cm^2。[结论]供试树种和菌种对叶片病斑大小都有显著影响;供试5种疫霉对苹果、杏、山楂、核桃叶片的致病性依次为:P.plurivora>P.lacustris>P.gregate≈P.gonapodyides>P. sp.;苹果、杏、山楂和核桃这4种植物叶片对以上5种疫霉菌的感病性依次为:核桃>杏>山楂>苹果。

[Objective] Pathogenicity investigation of the Phytophthora was carried out among the main fruit tree species in Xinjiang wild forest to understand the possible causes of the decline of wild fruit forest in Xinjiang and the potential risks caused by Phytophthora.[Method] By inoculating mycelium plugs artificially on the in vitro leaves, collections of Phytophthora: Phytophthora plurivora, P. gonapodyides, P. lacustris, P. gregate, P. sp. from Xinjiang were inoculated in the health leaves of apple, apricot, hawthorn, and walnut trees, respectively, and observing and recording the disease spot size one week later. Two-way analysis of variance(ANOVA) was implemented to find the differences among the treatments by software R.[Result] There were significant differences in the size of disease spots after inoculation of 5 Phytophthora strains on 4 host leaves. Among them, P. plurivora and P. lacustris had larger lesions after inoculation on leaves which were 18.68 cm^2 and 14.14 cm^2. Among the host plants, the leaves of walnut and apricot trees had larger disease spots which were 18.68 cm^2 and 9.55 cm^2.[Conclusion] The Phytophthora pathogenicity on the leaves of apple, apricot, hawthorn and walnut is in the order of P. plurivora>P. lacustris>P. gregate≈P. gonapodyides>P. sp. Among leaves of the 4 host trees(apple, apricot, hawthorn and walnut), the susceptibility to the 5 Phytophthora strains mentioned above is in the order of walnut>apricot> hawthorn >apple.