马铃薯种质资源黑胫病抗性评价及品种差异分析OA

[Objective]The study aimed to assess the resistance differences variations among the major potato varieties cultivated in Yunnan province and identify resistant germplasm resources to support breeding programs and sustainable production.[Method]Seventeen potato cul-tivars were evaluated for resistance to two pathogenic strains,Pectobacterium atrosepticum and P.brasiliense,using tuber slice inoculation and seedling stem puncture inoculation assays.Resistance was assessed at both the tuber and plant levels,with lesion area ratio(percentage of le-sion area)and disease index used as evaluation parameters.Cluster analysis was performed to comprehensively classify the resistance levels of the tested cultivars.[Result]Tuber inoculation results showed that six of the 17 cultivars exhibited stable resistance to blackleg pathogens.A-mong them,'Longshu 7'and'Xuanshu 11'showed high resistance under three treatments(Pectobacterium brasiliense,P.atrosepticum,and a mixed inoculation of the two pathogens).The lesion ratios of'Xuanshu 11'were 12.85％,12.68％and 9.03％,respectively,while those of'Longshu 7'were 14.34％,14.22％and 11.98％.'Lishu 6'showed lesion ratios of 24.95％,18.43％and 17.92％,and'Ganba Yangyu'showed 21.24％,21.29％and 23.30％under the three treatments,all indicating resistance.In contrast,'Qingshu 9'exhibited le-sion ratios of 79.40％,62.00％and 74.41％,and'Xuanshu 2'showed 79.40％,76.58％and 66.91％,both indicating high susceptibili-ty.The results of the greenhouse pot seedling inoculation experiment were generally consistent with those of the tuber inoculation test.Five days after inoculation,the disease index of'Longshu 7'and'Xuanshu 11'under all three treatments was lower than 15 and the incidence rate was lower than 33.33％,indicating high resistance.In contrast,'Qingshu 9'showed a 100％incidence rate and a disease index higher than 70 under all treatments,indicating high susceptibility.[Conclusion]Significant differences in resistance to potato blackleg were observed among the tested cultivars.'Xuanshu 11'and'Longshu 7'exhibited stable and high levels of resistance under both inoculation methods and could serve as valuable germplasm resources for resistance breeding and commercial cultivation.'Qingshu 9'and'Xuanshu 2'were highly susceptible,while the remaining cultivars displayed intermediate resistance levels.