Study On Biological Characteristic & PCR Detection And Isozyme Of Plasmodiophora Brassicae In Rape

In the experimentation , rape root of clubroot disease from Pixian county of Chengdu city was used for the study of the symptom and the effect on output of rape ; distilled the resting spores of Plasmodiophora brassicae in rape , study the modality and biological characteristics of P. brassicae in rape ; use PCR technology amplicated the DNA of P. brassicae extracted from rape and cruciferae, which came from Pixian , Tianquan , Pengzhou . E'meishan , Mianzhu , Meishan , Guanghan , Pengshan , Shenfang , Xindu , Y' an of Sichuan province , and the PCR products were cloned , then analyse the difference of the sequences in molecule level ; Through testing the activity of POD and PPO , the electrophoresis of POD and esterase isozyme of four rape varietals , principium groped for the rule of isozyme's change after rape were invaded by P. brassicae . The main results were showed as follows :1 Symptom of clubroot disease in rapeRape can be invaded by P. brassicae during all its growth period , especially when it is young. The disease only damage the root, its root will outgrow a lot of tumours when rape is invaded by P. brassicae , different shape and different size. Commonly, the tumours are bigger and fewer in taproot than in fibre. To sum up , the symptom of clubroot disease in rape is similar to it in cruciferae.2 Modality of resting spores and primary zoospores of P. brassicaeP.brassicae consists in the tumid cells of rape root, separate or mass Just as the spawn in light microscope , a group of resting spores are straw yellow, and one of them is achromaticity. The resting spores were nearly spherical, not slippery and mamillated on the wall of spores in scanning electron microscope , their diameters is from 1.9 to 4.3μm , and the mean of diameters is 3.5μm . The primary zoospores with unequal length biflagellates were nearly spherical , or nephroid , or oval in transmission electron microscope , and their size is from 1.6 to 3.5μm , the mean of size is 2.8μm . The changing course of the primary zoospores is : the resting spores turned into the primary zoospores, the silent spores orderly, and then one silent spore germinated out a tubal structure , the tubal structure invade the...