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期 刊 ：植物保护学报 2006年

关键词：泽兰实蝇；寄生；微生境；紫茎泽兰；有性繁殖；

Keywords:Procecidochares utilis, parasitizing behavior, microhabitat, Eupatorium adenophorum, sexual reproduction,

摘 要 ：泽兰实蝇Procecidochares utilis Stone是紫茎泽兰重要的专性寄生性天敌,有性繁殖是紫茎泽兰长距离扩散蔓延的主要途径。为评价泽兰实蝇在不同微生境中对紫茎泽兰的控制作用,在四川省德昌县选择沟谷地、撂荒地、果园和马尾松林地4种微生境,采用田间调查结合盆栽试验的方法,分析了泽兰实蝇对紫茎泽兰的寄生规律以及有性繁殖的影响。结果表明,泽兰实蝇在不同微生境中对紫茎泽兰寄生率的高低依次为沟谷地31.7%、马尾松林地28.1%、果园26.1%和撂荒地13.5%,这一顺序反映了泽兰实蝇的寄生率有随微生境中土壤含水量升高而增加的趋势。泽兰实蝇寄生后,紫茎泽兰单位面积上的花序数和种子千粒重均显著下降,而单个花序内的种子数无显著变化。此外泽兰实蝇寄生后紫茎泽兰种子的长度和宽度、种子活力、萌发率和出苗率均呈下降趋势,降幅分别在8.1%~14.9%、14.7%~18.4%、29.8%~37.9%、28.6%~61.8%和58.7%~69.1%之间,说明泽兰实蝇寄生影响了种子的生命力,从而对紫茎泽兰的扩散蔓延起到一定的抑制作用。

Abstract:Procecidochares utilis Stone is an important specific natural enemy parasite on Eupatorium adenophorum Sprengel, and the sexual reproduction is the main approach for the invasion and expansion of E.adenophorum. In order to evaluate the control efficiency of P.utilis against E.adenophorum in different microhabitats, four different microhabitats, namely valley, wasteland, orchard, and woodland of pine trees, were selected to investigate the parasitic pattern and its influence on sexual reproduction of E.adenophorum in Xichang County, Sichuan Province using the method of field survey and pot experiments. The results showed that P.utilis had significant selectivity for microhabitats of parasitizing. The parasitizing rate in valley microhabitat (31.7%) was the highest, followed by woodland of pine tree (28.1%), orchard (26.1%) and wasteland (13.5%). The sequence of parasitizing rate implied that the tendency of parasitizing rate increases with the increase of water content of soils in the microhabitats. After parasitizing, the amount of anthotaxy and the 1000-grain weight of E.adenophorum decreased significantly in different microhabitats, while the effects on the average seed amount within the anthotaxy were not significant. The seed length and width, the seed vigor, germination rate and emergence rate of E.adenophorum were all reduced significantly, and the decrease extent were 8.1%-14.9%, 14.7%-18.4%, 29.8%-37.9%, 28.6%-61.8%, and 58.7%-69.1%, respectively. The results suggested that the parasite by P.utilis had lowered the degree of the seed vitality, thus have the inhibiting function to invasion and expansion of E.adenophorum.

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