中国农业科学 ›› 2022, Vol. 55 ›› Issue (20): 3939-3947.doi: 10.3864/j.issn.0578-1752.2022.20.006

• 植物保护 • 上一篇    下一篇

基于地上部症状的玉米根腐病分级及严重度与农艺性状的关系

刘树森(),孙华,石洁(),郭宁,马红霞,张海剑   

  1. 河北省农林科学院植物保护研究所/河北省农业有害生物综合防治工程技术研究中心/农业农村部华北北部作物有害生物综合治理重点实验室,河北保定 071000
  • 收稿日期:2022-05-10 接受日期:2022-06-13 出版日期:2022-10-16 发布日期:2022-10-24
  • 通讯作者: 石洁
  • 作者简介:刘树森,E-mail: shusenliu@163.com
  • 基金资助:
    国家现代农业产业技术体系(CARS-02);河北省重点研发计划(20326501D)

Grading Criterion of Maize Root Rot Based on Aboveground Symptoms and the Relationship Between Severity and Agronomic Traits

LIU ShuSen(),SUN Hua,SHI Jie(),GUO Ning,MA HongXia,ZHANG HaiJian   

  1. Plant Protection Institute, Hebei Academy of Agricultural and Forestry Sciences/IPM Centre of Hebei Province/Key Laboratory of IPM on Crops in Northern Region of North China, Ministry of Agriculture and Rural Affairs, Baoding 071000, Hebei
  • Received:2022-05-10 Accepted:2022-06-13 Online:2022-10-16 Published:2022-10-24
  • Contact: Jie SHI

摘要:

【目的】 基于苗期根腐病植株地上部症状制订规范、简单易操作的玉米根腐病严重度分级标准,并明确不同病害严重度对玉米生长发育和产量的影响。【方法】 采用开沟点播的方式播种玉米,同时在两穴种子中间撒施禾谷镰孢(Fusarium graminearum)接种体进行根腐病接种。出苗后,持续观察根腐病的症状,根据5叶期植株地上部症状制订病害严重度分级标准;分别于11叶期和蜡熟期测量不同病情级别植株的株高、茎基部粗、茎粗、穗位高等农艺性状;同时,在蜡熟期调查根腐病植株的茎腐病发病率;收获后,测量穗粗、穗长、秃尖长、穗行数、行粒数、百粒重、穗粒重等产量相关性状,并分析根腐病严重度与产量性状的关系。【结果】 通过观察发现,1叶期症状表现为叶色发黄,叶片尖端萎蔫,种子根和胚轴上可见黄褐色病斑,部分中胚轴维管束组织褐变。3叶期,发病植株胚轴和根系上有不同程度的坏死斑,胚轴的坏死导致部分植株地上部枯死。5叶期症状主要分为以下3种类型,由下而上叶片出现不同程度黄化,甚至逐渐干枯;植株发育缓慢或者停滞,直观表现为植株矮小;植株枯死。根据5叶期植株地上部症状,将根腐病病情严重度划分为1、3、5、7和9级共5个级别。农艺性状调查结果显示,在11叶期和蜡熟期,随着根腐病病情级别升高,株高、茎基部粗、茎粗和穗位高呈逐级降低趋势,且大部分9级植株发育受到抑制或处于生长停滞状态,出现分蘖或畸形。茎腐病调查结果表明,部分玉米根腐病病株在生长后期发展为茎腐病,茎腐病的发病率随着根腐病病情级别升高呈降低趋势。产量性状的分析结果表明,根腐病病情级别与7项产量相关性状均呈负相关,当病情达到5级时即可造成50%以上的产量损失,9级时甚至造成绝产。【结论】 在系统观察、描述玉米根腐病症状的基础上,基于5叶期植株地上部症状制订了高效、简便易行的根腐病严重度分级标准;根腐病的发生会降低玉米的株高、茎粗、穗位高等,且易导致茎腐病;根腐病严重度与多项产量相关性状均呈负相关。研究结果对于玉米品种抗根腐病评价、根腐病防治以及产量损失评估等具有指导意义。

关键词: 玉米根腐病, 地上部症状, 严重度, 分级标准, 农艺性状

Abstract:

【Objective】This study aimed to establish a standardized and easy-to-operate grading criterion for maize root rot severity based on the aboveground symptoms at the seedling stage, and to clarify the effects of different disease severities on maize growth and yield.【Method】The maize was planted with hole-sowing, and the inoculum of Fusarium graminearum was placed between the seeds of two holes for root rot inoculation. After emergence, the symptoms of root rot were observed continuously, and the grading criterion of disease severity was established based on the symptoms of the aboveground parts at the V5 stage. The agronomic traits of plant height, stem base diameter, stem diameter, and ear height of plants with different grades were measured at the V11 stage and dough stage, respectively. At the same time, the incidence of stalk rot, which developed from root rot, was investigated at the dough stage. After harvesting, yield-related traits, including ear diameter, ear length, bare top length, row number per ear, kernel number per row, 100-kernel weight, and kernel weight per ear, were measured. Then, the relationship between root rot severity and yield-related traits was analyzed.【Result】At the V1 stage, the symptoms of yellowing leaf and wilting tip, seminal root and mesocotyl with yellowish-brown lesions, and some mesocotyl with browned vascular tissue were observed. At the V3 stage, the mesocotyl and root system of the diseased plants were necrotic to varying degrees, and the aboveground part of some plants was dead due to the necrotic mesocotyl. At the V5 stage, it can be classified into the following three types, i.e., leaves showed yellowing to varying degrees, or even gradually withered; the plant appearance was a dwarf and developed slowly and stagnantly; the plant died. Furthermore, the severity of root rot was divided into grades 1, 3, 5, 7 and 9 based on the aboveground symptoms at the V5 stage. Investigation of agronomic traits showed that plant height, stem base diameter, stem diameter and ear height decreased gradually with the increase of disease grade of root rot at the V11 stage and dough stage. At the same time, the development of most 9-grade plants was inhibited or stagnated, and showed tillering or deformity. The investigation of stalk rot indicated that some of the root rot plants developed into stalk rot in the late growth stage. The incidence of stalk rot showed a decreasing trend with the increase of root rot grade. The analysis of yield traits showed that the grade of root rot disease was negatively correlated with seven yield-related traits. It could cause more than 50% of the yield loss at the 5-grade, and even no grain at the 9-grade.【Conclusion】Based on the observation and description of the symptoms of maize root rot, an efficient and easy-to-operate grading criterion reflecting disease severity was formulated according to the aboveground symptoms at the V5 stage. Root rot disease can reduce the plant height, stem diameter and ear height, and easily lead to cause stalk rot. The severity of root rot is negatively correlated with yield-related traits. The results of this study are expected to guide resistance evaluation of varieties against root rot, disease control and yield loss assessment.

Key words: maize root rot, aboveground symptom, severity, grading criterion, agronomic trait