Single Spore Isolation And Identification Of Physiological Races Of Plasmodiophora Brassicae Of Cruciferae Vegetables

Cruciferous vegetable root swelling caused by Plasmodiophora brassicae Woronin.infection is a worldwide soil-borne disease that is difficult to prevent and threatens the sustainable development of the cruciferous vegetable industry.Selecting disease-resistant varieties is an effective way to control cruciferous root swelling disease.It is the basis for the selection and application of disease-resistant varieties to clarify the physiological race types and geographical distribution of Plasmodiophora brassicae in different regions of my country.In this paper,the Williams identification system is used to identify the physiological races of the obtained Plasmodiophora brassicae monospore strains.The main results are as follows:1.The single spore isolation system of Plasmodiophora brassicae was optimized.The traditional water agar method was improved.The 0.01% methylene blue staining solution and 1.5% sterilized agarose solution were made into a methylene blue agarose layer with a volume ratio of 100 μ L: 30 m L.the single spore of Rhizopus could be successfully isolated under the microscope.The single spore isolation method based on methylene blue agarose method solved the problems of traditional single spore isolation methods,such as fuzzy target,difficult to pick and separate,etc.the accuracy and efficiency of single spore isolation were significantly improved,and the effect on the spore vitality of Rhizopus brassicae was small.The survival rate of single spore isolation was 97.31%.2.81 strains of rhizopus were collected from different areas.93 strains of monosporal mycorrhiza of clubroot were isolated and cultured from 16 different regions of cruciferous vegetables in 11 provinces of China.The monosporal mycorrhiza strains of clubroot were propagated by small lump method and twice in original pot.81 monosporal mycorrhiza with different weight were obtained.3.Identify the physiological race types of 36 rhizobia monospora strains in 9 regions of my country.Using the Williams identification method to carry out physiological race identification test on the monospore strains obtained from the isolation and expansion of monospores,five physiological race types P2,P4,P5,P8,and P13 were identified,among which the monospores identified as P4 There are 22 strains,accounting for 61.11% of the total number of identifications.P2,P5,P8,and P13 account for 16.67%,11.11%,8.33%,and2.78% of the total number of identifications.P4 is significantly higher than the other four physiological race types identified,As the dominant race.Through the isolation and expansion of monospores in different regions of my country,the rhizobia monospore strains were identified by the Williams identification method.The type and distribution of the physiological races of root swelling in the main producing areas of cruciferous vegetables in my country have been clarified,which provides a theoretical basis for the selection and rational distribution of resistant varieties based on the distribution of races in different regions in my country.Plan targeted planting of disease-resistant varieties to provide better technical support for effectively controlling the spread of cruciferous vegetable root swelling.