10份西南山区常用玉米自交系白斑病抗性鉴定及遗传多样性分析OA

This study systematically evaluates the resistance levels of 10 commonly used maize inbred lines in Guizhou Province to southern maize white spot and conducts a population genetic diversity analysis based on SSR molecular markers.The research aims to explore genetic resources related to southern maize white spot resistance in the Guizhou region,providing a foundation for constructing an efficient disease-resistant germplasm system.The resistance identification of southern maize white spot was carried out in Jiangdong Township and Mengga Town,Dehong Prefecture,Yunnan Province,during the 2022-2024 period.PCR amplification was performed using 69 pairs of SSR primers with clear and stable bands,and genetic diversity and cluster analyses were conducted using POPGENE 32 and NTSYS-2.10e software.The resistance identification results showed that inbred line T32 exhibited stable high resistance,while inbred line Jiao51 showed high susceptibility.SSR marker analysis detected a total of 308 alleles,with an average number of alleles per locus(Na)of 4.46.Population genetic parameters revealed the following:Nei's gene diversity index(H)ranged from 0.320 to 0.860,with an average of 0.680;Shannon's information index(I)ranged from 0.500 4 to 2.025 3,with an average of 1.311 2;and the polymorphism information content(PIC)ranged from 0.320 to 0.860,with an average of 0.678.Among these,marker umc1753 showed the highest polymorphism.Based on genetic similarity coefficients,cluster analysis was performed.At a similarity coefficient of 0.356,S37,Su11,and Shuang M9 clustered into one subgroup,all of which possess tropical ancestry.At 0.312,Qi319,J106,Zheng58,and QL16 formed another subcategory,all with temperate ancestry.At 0.269,Jiao51 and HC clustered into a subcategory.At 0.257,T32 grouped with the remaining inbred lines(except Jiao51 and HC)into a separate subcategory.The results indicate that the 10 inbred lines used in this study exhibit relatively rich genetic diversity,which can meet the the demand for parental genetic variation in maize breeding.Among them,inbred line T32 shows high resistance to southern maize white spot,along with certain resistance to gray leaf spot and head smut,making it a key material for disease resistance gene mining,hybrid improvement,and resistant germplasm development in the Guizhou region.