Identification Of Potato Germplasm Resources Resistance To Common Scab And Genetic Diversity Analysis On Resistance Resources

Potato scab caused by Streptomyces(Actinobacteriaceae)is a kind of soil-borne disease.Potato scab occurs currently widely in China,and shows a trend of increase year by year.However,there is no effective chemical control method can be used to completely control it,cultivating anti-scabs potato varieties is one of the most cost-effective ways to solve this problem thoroughly.The primary task of disease resistance breeding is to screen the germplasm resources that anti-scab.The analysis of the genetic relationship among the resistance resources can provide the theoretical basis for the breeding of scar resistance cultivars.In this research,108 potato germplasm resources were evaluated by potted inoculation experiment inoculating with S.scabies,which is one kind of pathogens causing potato common scab.And then,screen the resistant potato resources.Meanwhile,SSR molecular marker technique was used to analyze the genetic relationship among the resistant resources.Main results gained are as bellow:(1)9 resources which were identified as potato scabs high resistance including: Marispeer,-2,L08104-12,Ling Tian Hong Mei,898006,S,CEG-69.1,88-1-19,R1R2,MEX 750847;11moderate anti-resources with potato scab disease were : Ken Shu No.1? Long Shu No.14 ?Ji Zhang Shu No.8?2070(50)?958?393234.2(sh5)?84115 Mariseer?AGB-69-1?REICHE?Ji Nong958 ? 130.High anti-resources and moderate anti-resources are identified as disease resistance resources.(2)9 pairs of SSR primers were screened out from 20 pairs of primers with high polymorphism and clear bands,and we further screened out the optimal PCR reaction conditions and polyacrylamide gel concentrations for the 9 pairs of primers.(3)9 pairs of SSR primers were used to analyze the germplasm resources of the scab,and 167 polymorphic bands were amplified.The percentage of polymorphic bands reached 94.3%.Fragments amplification products were from 100 bp to 2 000 bp.The genetic similarity coefficient ranged from 0.5210 to 0.7904 with an average of 0.6946.The UPGMA cluster analysis showed that,at the genetic coefficient of 0.6300,all the tested resources could be divided into 3 groups,the genetic relationships among the resistance resources were revealed from DNA molecular level.Among them,the genetic similarity coefficient of Potato cultivar Ling Tian Hong Mei and Potato strain 958 was the highest,and the genetic relationship was relatively close.The potato similarity coefficient was the lowest in potato strain R1R2 and potato strain 393234.2(sh5),and the genetic relationship was relatively far.