玉米种质资源对拟轮枝镰孢与禾谷镰孢穗腐病的抗性精准鉴定与分析

Precise characterization and analysis of maize germplasm resources for resis-tance to Fusarium ear rot and Gibberella ear rot

穗腐病是我国玉米生产上的重要病害,严重影响玉米的产量和品质。利用抗病品种是控制穗腐病的安全有效措施。抗性资源是开展抗病育种的物质基础。本研究优化和完善了玉米种质抗镰孢穗腐病精准鉴定的方法,比较分析了花丝通道注射接种和果穗注射(创伤)接种鉴定的穗腐病抗性,发现2种方法鉴定出的抗性结果具有高度的一致性(相关系数r≥0.90)。2018—2020年,在北京昌平和四川西昌,利用花丝通道注射接种法,对690份代表性玉米种质进行了抗拟轮枝镰孢穗腐病的精准鉴定与评价,筛选出H446、YCF、辽2309、吉资1055、Y1723、XF8-3、铁97085等35份具有稳定抗性的种质,占比为5.07%。6个环境下玉米对拟轮枝镰孢穗腐病抗性的相关系数为0~0.48,同一年度(2018、2019和2020年)2个鉴定点穗腐病抗性值之间的r值分别为0.03、0.20和0.15,3个年度间穗腐病综合抗性的相关系数为0.20、0.30和0.35,表明在不同环境下玉米对拟轮枝镰孢穗腐病的抗性反应存在较大差异。在辽宁沈阳和四川西昌共6个环境下,对690份种质进行了抗禾谷镰孢穗腐病精准鉴定,6个环境下玉米种质抗性的相关系数为0~0.39,2018、2019和2020年2个鉴定点之间的r值分别为0.05、0.25和0.29,表明环境因素对玉米抗禾谷镰孢穗腐病的表型存在较大影响;3个年度间镰孢穗腐病综合抗性的r值为0.14、0.20和0.13,显示年度间综合抗性差异较大。共鉴定出17份对禾谷镰孢穗腐病具有稳定抗性的种质(H446、MC7528、Y1632、Y1679、吉资1055、铁97085等)。690份种质对上述2种穗腐病抗性的相关系数为0.52,表明其对2种穗腐病的抗性存在中等水平的相关性。H446、吉资1055、铁97085三份种质在所有鉴定环境中均对2种穗腐病表现出稳定抗性,是玉米抗穗腐病育种和品种抗性改良的宝贵资源。

Ear rot is a severe disease in maize production in China,which often leads to a considerable decline in yield and quality.The development and utilization of resistant cultivars is an economical and effective method for controlling ear rot.Resistant resources are the material basis for resistance breeding.The methods for precise identification of maize germplasm resistance to ear rot were optimized and improved.Correlation analysis between silk channel inoculation and ear injection inoculation(trau-matic inoculation)for screening of maize resistance to ear rot was performed and correlation coefficients(r)were not less than 0.90,indicating high correlation between maize ear rot resistance identified by silk channel and ear injection inoculation.The precise evaluation of 690 maize accessions resistance to Fusarium ear rot(FER,caused by Fusarium verticillioides)was con-ducted with silk channel inoculation at six different environments in Changping of Beijing and Xichang of Sichuan from 2018 to 2020.A total of 35 maize resources with stable FER resistance,such as H446,YCF,Liao 2309,Jizi 1055,Y1723,XF8-3,Tie 97085 and so on,were screened out,accounting for 5.07%of total accessions.Correlation coefficients of maize resistance to FER between any two sites among six different environments varied from 0 to 0.48.The r-values between two sites in 2018,2019,and 2020 were 0.03,0.20,and 0.15,respectively.The r-values between pairwise annual comprehensive FER resistance among three years were 0.20,0.30,and 0.35,indicating that the resistance reaction of 690 accessions to FER exhibited obvious differences among different environments.During 2018-2020,690 maize resources were precisely identified for resistance to Gibberella ear rot(GER,caused by Fusarium graminearum)with silk channel inoculation at six different environments in Shenyang of Liaoning and Xichang of Sichuan.Correlation coefficients of GER resistance in 690 maize resources between any two sites among six en-vironments ranged from 0 to 0.39.The r-values between two sites in 2018,2019,and 2020 were 0.05,0.25,and 0.29,respectively,indicating that the environments had a relatively great influence on GER resistance in maize.The r-values between pairwise an-nual comprehensive GER resistance among three years were 0.14,0.20,and 0.13,indicating considerable differences in annual comprehensive resistance.Seventeen inbred lines(H446,MC7528,Y1632,Y1679,Jizi 1055,Tie 97085,and so on)with stable resistance to GER at diverse environments were identified.The r-value of 0.52 between FER and GER resistance in 690 maize germplasm exhibited moderate correlation.The six-point experimental data for FER and GER resistance indicated three maize inbred lines(H446,Jizi 1055,and Tie 97085)expressed stable resistance to both FER and GSR,which were precious resources for breeding ear rot resistant varieties or improvement of cultivar resistance.