Black Sunflowers Bacteria Identification And Sunflower Stalk Varieties Resistance Screening

Sunflower black stalk was a newly discovered disease in our country,resulting in serious losses of production and quality,had became one of the key factors hindering the development of sunflower industry.In this study,the pathogens collected from some of the main sunflower producing areas were isolated and identified.At the same time,the biological characteristics of the pathogen and the pathogenicity of the strain and the resistance of the sunflower germplasm were analyzed,which provided the basis for the further development of sunflower resistance to black stem.The main conclusions of this paper are as follows:1.Severe plots were collected from Ji Lin,Inner Mongolia Xin Jiang and He Bei sunflower black stems.Thirty-four strains of the typical symptoms were isolated by pathogen isolation and 18 strains were obtained by tissue separation.The results showed that the biological characteristics and pathogenicity of 18 sunflower black stem strains in Ji Lin,Inner Mongolia Xin Jiang and He Bei provinces were identified as consistent with the description of Phoma macdonaldii.2.The pathogenicity of YS04,HJB,ZJK-2 and BC202 was relatively strong,the symptoms were fast,the disease was early and the symptoms of black lesions were serious.88-1k,WLH3,ZJK-ZJK-8,88-5h,BJ2,88-2h,HJC,JBL4,ZJK-12,ZJK-8,885h,BJ2,88-2h,HJC,JBL4,ZJK-12,ZJK-5,WZ15 and BC202 pathogenic weak,slow infection,slow onset,mild symptoms of stem black spots.3.The results showed that the resistance of three sunflower species in different sunflower germplasm resources identified in this experiment was close to that of disease control(JK103),and the remaining 48 were Test materials LD5009,132124,132117and so on are susceptible sunflower germplasm resources.4.By comparing the defensive enzyme activities of 52 tested sunflower germplasm resources,there was a difference in the trend of defensive enzyme activity among sunflower germplasm resources with different resistance.The relative activities of POD,SOD and CAT in the other tested materials were lower than those of the susceptible control varieties(LD5009),and the control activities of the tested samples were similar to those of the control varieties(JK103)Lesions symptoms than the susceptible control varietics LD5009 to large and serious.Therefore,these materials are more sensitive than the susceptible control species(LD5009).Namely:132083,132088,131023 three sunflower material resistance close to the disease control varieties(JK103),the rest of the test materials are high sense of sunflower germplasm resources.The results showed that the results of defense enzyme resistance identification were consistent with the trend of spot identification,and the determination of defense enzyme activity could be used to screen sunflower resistant to black stem.