Screening For Clubroot Resistant Germplasm In Brasscia Napus L And Characterization Of Pathogenicity Of Plasmodiophora Brassicae From Different Regions In Sichuan Province

Rapeseed is one of the important oil crops in the world, and also is our country’s traditional oil crops.In recent years, with the expansion of the disease area of clubroot in our country,and severity of disease increase constantly,clubroot seriously affected the yield and quality of rapeseed.Resistant breeding is the basis of disease integrated, the production practice has proved that the disease-resistant varieties is the most cost-effective and environmentally way to prevent diseases.Screening resistant materials from Brasscia napus L.which collected and bred by Rapeseed research center of Sichuan agricultural university and identifying the pathogenicity of Plasmodiophora brassicae from three different regions in Sichuan Province of this research, which provide the theoretical basis for the resistant inheritance of clubroot,breeding of clubroot-resistant varieties and classification of Plasmodiophora brassicae physiological race.1.Using the Plasmodiophora brassicae from Sancha Dayi county as the pathogenic bacteria,and through the injection method to Screen resistant materials from 281 Brasscia napus L for the initial screening.44 relatively resistant materials from the initial screening were re-tested in a second screening test, including 3 "Common backbone inbred lines "materials,26 "Resource lines "materials,12 " New inbred line " materials and 3 new combination hybrid rape materials.2.Using the 44 initially identified resistant materials and 10 susceptible materials as the object for the second screening, of the all 44 resistant materials,5 are high resistance,consist of No 30 of "Common backbone inbred lines" and No 104、 106、107、108 of "Resource lines",4 are resistance,24 are middle susceptible,10 are susceptible.3.Comparing the injection method and sick soil method,the average severity index of sick soil method is 24.57 higher than injection method’s 21.79,the average disease incidence of injection method is 41.67 higher than sick soil method.There is no obvious distinction between the tow method,choosing injection method as the screening method for the screening.4.In the three periods of disease resistance identification he disease effect of Spring and Autumn are better than Winter, the average disease incidence of Spring is 90.47%,the average severity index is 69.40;the average disease incidence of Autumn is 96.49%,the average severity index is 68.32; the average disease incidence of Winter is 30.70%,the average severity index is 15.54.Choosing Spring and Autumn as the screening period for the screening.5.Using 20 Representative Brasscia napus L.to identify the pathogenicity of Plasmodiophora brassicae from three different regions in Sichuan Province,The overall disease incidence of 20 Brasscia napus L is:Kangding<Dayi<Guanghan,and the overall disease severity is also:Kangding<Dayi<Guanghan,it proves that pathogenic capability of Plasmodiophora brassicae from three regions is: Kangding<Dayi<Guanghan...