玉米自交系对瘤黑粉病抗性鉴定及遗传多样性分析

Identification and Genetic Analysis of Maize Inbred Lines Resistant to Ustilago maydis

为明确30份玉米自交系对瘤黑粉病的抗病性,于2018-2019年在甘肃省定西市安定区凤翔镇进行试验,其中选择高抗品种‘齐319’和高感品种‘掖478’为参照,在玉米6叶1心期,采用注射法对玉米幼苗接种黑粉菌,在接种的第10天和第20天统计发病率、以第20天的发病率作为鉴定玉米种质抗病性的依据,并对遗传多样性和亲缘关系利用SSR分子标记进行分析。研究结果表明:接种第10天发病率为3.33%~53.33%,第20天发病率为10.00%~86.67%;抗性评价上,表现为抗性的材料有7份,其中抗病的材料有1份,中抗的材料有6份,其余23份表现为感瘤黑粉病;69对多态性SSR引物在32份材料中共扩增出272个等位基因变异,每对引物检测出等位基因数3~6个,平均3.64个,多态性信息量为0.435~0.846,平均0.764;当遗传相似系数为0.643时,69对SSR引物将32份种质资源分为4组类群,第Ⅰ组有19份材料,其中有8份抗性材料;第Ⅱ组有7份材料,有6份感病材料和1份高感病材料;第Ⅲ组有3份高感病材料;第Ⅳ组有3份高感病材料。抗病材料都集中在第Ⅰ组,其遗传背景较窄。

In order to determine the disease resistance of 30 maize inbred lines against Ustilago maydis,an experiment was conducted in Fengxiang town,Anding district,Dingxi city,Gansu province from 2018 to 2019,variety‘Qi 319’of highly resistant to disease and highly susceptible variety‘Ye 478’were used as control.At the 6-leaf and 1-heart stages of maize,maize seedlings were inoculated with smut by injection method.Morbidity statistics were made on the 10 d and 20 d after inoculation,the incidence of 20d was used as the basis to identify the disease resistance of maize germplasm and genetic diversity and genetic relationship were analyzed by SSR molecular markers.The results showed that on the 10 d after inoculation,the morbidity was 3.33%-53.33%,and on the 20 d,the morbidity was 10.00%-86.67%;in resistance evaluation,7 materials were resistant to disease,of which 1 was resistant,6 were neutral resistant and 23 were susceptible to Ustilago maydis;69 pairs polymorphic of SSR primers were detected and a total of 272 alleles were amplified in the 32 materials,the average number of allele per SSR locus was 3.64 ranged from 3-6,the polymorphism information content(PIC)for the SSR loci varying from 0.435-0.846 with an average of 0.764;when the genetic similarity coefficient was 0.643,32 germplasm resources were divided into 4 groups by 69 SSR primers.There were 19 materials in groupⅠ,in which 8 materials were disease-resistant,There were 7 materials in groupⅡ,in which 6 materials were susceptible and 1 highly susceptible material.There were 3 highly susceptible materials in groupⅢ,3 highly susceptible materials in groupⅣ.The resistant materials were all concentrated in groupⅠ,and their genetic background was in narrow range.