玉米种质资源抗两种镰孢穗腐病的大规模鉴定

Large-scale Identification of Maize Germplasm Resources for Resistance to Ear Rot Caused by Two Fusarium Species

玉米穗腐病是一种主要由拟轮枝镰孢和禾谷镰孢引起的真菌性病害,严重威胁国家粮食安全。随着气候和耕作制度的变化,穗腐病已成为玉米生产上发生最普遍、危害最重的病害之一,大规模的抗病种质资源鉴定有利于解决因优良抗病种质资源缺乏而导致的抗病品种培育困难的问题。本研究在建立了玉米穗腐病高通量抗性鉴定平台的基础上,采用滚动式抗源鉴定策略,在初级鉴定阶段采用单环境、单重复的策略对大量种质进行初步筛选,随后对初级鉴定中的高抗种质进行多重复、多环境、多年份的次级鉴定,逐步淘汰感病种质。2018-2020年间对10524份玉米种质资源进行了抗镰孢穗腐病的初级鉴定,共筛选到191份高抗种质,进一步对高抗种质进行滚动式次级鉴定,最终筛选出18XDHNAM11-20、H5084、M C303等59份具有稳定抗性的种质,其中24份种质在5年的鉴定中均表现为抗病。从59份抗病种质的杂种优势类群看,抗病种质可分为5个类群:温热互导群、国内Reid群、NSS群、SS群及黄改群,基本涵盖国内最主要的杂种优势类群,其中来自温热互导群的抗病材料有24份,占抗病材料总数的41%。本研究抗病种质资源的发掘为玉米抗穗腐病育种提供了重要资源。

Maize ear rot is a fungal disease mainly caused by Fusarium verticillioides and Fusarium graminearum,which seriously threatens national food security.With the change of climate and farming system,ear rot has become one of the most common and most harmful diseases in maize production.Large-scale identification of disease-resistant germplasm resources is conducive to solving the difficulty of breeding resistant varieties due to the lack of good disease-resistant germplasm.In this study,based on the establishment of a highthroughput resistance identification platform for maize ear rot,a rolling resistance identification strategy was adopted,that is,in the primary identification stage,a large number of germplasm resources were initially screened using a single repeat and single environment strategy,and then in secondary identification stage the highly resistant germplasm from the primary identification stage was accurately evaluated under multiple environments and years,and the susceptible germplasm was gradually eliminated.During the year 2018 to 2020,a total of 191 highly resistant germplasm was identified from 10524 maize germplasm in the primary identification stage,and a total of 59 stable resistant germplasm,including 18XDHNAM11-20,H5084 and MC303,was finally identified through the secondary identification stage.Among them,24 germplasm showed resistance to Fusarium ear rot in the five years.In terms of heterosis groups of disease-resistant germplasm,the disease-resistant germplasm was divided into 5 groups,namely,tropical-temperate introduced heterosis group,Reid group,NSS group,SS group and Huangai group,which basically covered the most important heterosis groups in China.Among them,there are 24 resistant materials came from tropical-temperate introduced heterosis group germplasm,accounting for 41%of the total materials.These resistant germplasm resources identified in this study provide important resources for ear rot resistant breeding in maize.