不同真菌和植物种类对苜蓿滑刃线虫繁殖的影响

Effects of different fungi and plant species on reproduction of Aphelenchoides medicagus

为探究美国进境苜蓿滑刃线虫对真菌的取食特性以及对植物的寄生性,通过接种试验观察该线虫在链格孢、灰葡萄孢、禾谷镰刀菌、拟盘多毛孢和核盘菌等5种真菌,以及在菊花、大豆、苜蓿和三叶草等4种植物8个品种上的繁殖情况。结果表明,苜蓿滑刃线虫能取食5种真菌的菌丝体,但是在各真菌上的繁殖系数(Rf)有明显差异,在链格孢和拟盘多毛孢上能快速繁殖且数量很高,在灰葡萄孢上繁殖速度稍慢,但存活时间较长。接种苜蓿滑刃线虫后,大豆品种新叶出现轻微畸形或褐色病斑,苜蓿品种新叶出现畸形萎缩,而菊花和三叶草叶片没有症状;该线虫在各植物上的Rf值均低于1,表明这些植物不是合适的寄主。研究结果可为我国口岸实施外来植物线虫的检疫措施提供参考。

In order to explore the characteristics of Aphelenchoides medicagus intercepted from the USA in terms of fungal feeding and plant parasitism,the inoculation tests were carried out to evaluate the reproduction of nematodes on five fungal species,including Alternaria sp.,Botrytis cinerea,Fusarium graminearum,Pestalotiopsis sp.and Sclerotinia sclerotiorum,and on eight varieties of four plant species,including Chrysanthemum×morifolium,Glycine max,Medicago sativa and Trifolium repens.The results showed that A.medicagus could feed on the mycelia of five fungi,but the reproduction rates(Rf)of the nematodes on different fungi were significantly different.The nematodes could reproduce rapidly on the mycelia of Alternaria sp.and Pestalotiopsis sp.with high numbers,and relatively slower on the mycelia of Botrytis cinerea with high longevity.After inoculation with A.medicagus,the young leaves of soybean varieties exhibited slightly deformity or brown lesion spot,and the young leaves of alfalfa varieties showed malformation and shrink,while no symptoms were observed on the leaves of chrysanthemum and clover.The Rf values of nematodes on inoculated plant species and varieties were less than 1,which indicated that these plants were not suitable hosts.The results provided the useful information for Chinese ports to implement the quarantine measures for the exotic plant nematodes.