油菜根肿病菌形态及生物学特性研究

油菜根肿病近年在四川省发生日趋严重。本文报道了油菜根肿病菌休眠孢子的显微形态结构,其在扫描电镜下休眠孢子近球形,孢壁不光滑,有乳状突起,直径为1.9~4.3μm(平均3.5μm);透射电镜下游动孢子近球形、肾形或椭圆形,直径为1.6~3.5μm(平均2.8μm),同侧着生不等长尾鞭式双鞭毛。观察了休眠孢子萌发形成游动孢子、休止孢、休止孢再萌发形成芽管的过程。病菌休眠孢子萌发的最适温度是24℃,最适pH值是6.3,腐烂处理促进休眠孢子萌发,光抑制休眠孢子萌发,休眠孢子在过滤灭菌的根分泌物中萌发率最高为62.50%。

Modality and Biological Characteristic of Plasmodiophora brassicae in Rape

Recently,the incidence of crucifer clubroot in rape is gradually increases.This text reports the modality of resting spores of crucifer clubroot in rape.The resting spores are nearly spherical,not slippery and mamillated on the wall in scanning electron microscope,their diameters range from 1.9 to 4.3?μm,and the mean is 3.5?μm.The primary zoospores with unequal length biflagellates are in nearly spherical,or nephroid,or oval shape in transmission electron microscope,and their size varies widely from 1.6 to 3.5?μm,and the mean is 2.8?μm.It is observed that the changing course of the resting spores turn into the primary zoospores,the silent spores in order,and then one silent spore germinates out a tubal structure.The optimum temperature for the germination of resting spores is 24?℃,the optimum pH is 6.3.Treatment of rotted clubs is helpful to enhance the germinated rate.The visible light inhibit the germination of the resting spores.The highest germinated rate for the resting spores is 62.50% in the root exudates.The results show that the conditions for the germination of resting spores are accordant with the disease's generant condictions.