The Population Genetic Diversity Analysis Of Phytophthora Infestan Effect PiAVR2 And PITG＿04089

Potato is the fourth largest food crop in the world after rice,wheat and corn.Late blight caused by P.infestans is the most destructive disease in potato production.In order to successfully infect plants,P.infestans secretes a class of RXLR effector proteins to its host cells.This study analyzes the selected 18 strains from the four major potato farming regions in China.479 sequence of PiAVR2 and PITG＿04089 of effector genes were obtained respectively by Cloning sequencing method,Population genetics method was used to analyze the gene sequence.Understanding the population genetic structure and mutation mechanism of PiAVR2 and PITG＿04089 would help towards analyzing the effects of these genes to P.infestans population differentiation characteristics and evolutionary principles.At the same time,the physicochemical properties and protein disorders of PiAVR2 were analyzed,the toxic as well as non-toxic physicochemical properties of PiAVR2 were compared to evaluate their roles in the evolution of PiAVR2.This study was conducted on the effects of gene PiAVR2 genetic diversity on 18 P.infestans population from the four major potato farming areas,the results found that PiAVR2 displayed a higher genetic diversity,in which point mutation,deletion and insertion of base all contributed to the variation of PiAVR2.Protein disorder is an important feature of pathogen effector and plays an important role in the effector functions and identification of host resistant proteins.PiAVR2 may increase the degree of protein disorder in the effector region through amino acid mutation,and at the same time obtain the short protein interaction region,which changes the complex composition after binding with the substrate,thereby resulting to inability of the resistant protein R2 to recognize it.We analyzed the genetic diversity of the 18 P.infestans population effector gene PITG＿04089 of the four major potato farming areas in China.We found that the genetic diversity of the effector gene was high in china,and genetic differentiation between groups was low.The high genetic diversity observed is mainly caused by differences between the strains group,and contribution to the population genetic diversity between the cultivation areas was low.The genetic differentiation between the four farming areas was not clear understood,however,the northern farming area and the southwest mixed farming area had moderate genetic differentiation compared to others,but the overall differentiation degree was low.In addition,the results of the neutrality test showed that the effector PITG＿04089 gene had purification selection in the four major framing areas in China.