中国农业科学 ›› 2025, Vol. 58 ›› Issue (3): 493-506.doi: 10.3864/j.issn.0578-1752.2025.03.007

• 植物保护 • 上一篇    下一篇

青稞穗腐病发生与穗螨群体迁移的关系

童朝阳1(), 刘文华1, 张国欣1, 董春燕1, 张燕霞2, 徐晓伟1, 何东3, 刘何春4, 李杨4, 王凤涛1, 冯晶1, 姚小波4, 刘梅金5, 蔺瑞明1()   

  1. 1 中国农业科学院植物保护研究所植物病虫害综合治理全国重点实验室,北京 100193
    2 青海省海北藏族自治州农牧综合服务中心,青海海晏 810299
    3 日喀则市农牧业科学研究推广中心,西藏日喀则 857000
    4 西藏自治区农牧科学院农业研究所,拉萨 850032
    5 甘南藏族自治州农业科学研究所,甘肃合作 747000
  • 收稿日期:2024-10-10 接受日期:2024-11-10 出版日期:2025-02-01 发布日期:2025-02-11
  • 通信作者:
    蔺瑞明,E-mail:
  • 联系方式: 童朝阳,E-mail:ndtongzhaoyang@163.com。
  • 基金资助:
    国家现代农业产业技术体系建设专项(CARS-05)

The Relationship Between Occurrence of Hulless Barley Ear Rot and Population Migration of Grass Mite (Siteroptes spp.)

TONG ZhaoYang1(), LIU WenHua1, ZHANG GuoXin1, DONG ChunYan1, ZHANG YanXia2, XU XiaoWei1, HE Dong3, LIU HeChun4, LI Yang4, WANG FengTao1, FENG Jing1, YAO XiaoBo4, LIU MeiJin5, LIN RuiMing1()   

  1. 1 State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193
    2 Haibei Integrated Service Center for Agriculture and Animal Husbandry, Haibei Tibetan Autonomous Prefecture of Qinghai, Haiyan 810299, Qinghai
    3 Shigatse City Agriculture and Animal Husbandry Science Research and Promotion Center, Shigatse 857000, Xizang
    4 Institute of Agriculture, Xizang Academy of Agriculture and Animal Husbandry Sciences, Lhasa 850032
    5 Agricultural Science Research Institute of Gannan Tibetan Autonomous Prefecture, Hezuo 747000, Gansu
  • Received:2024-10-10 Accepted:2024-11-10 Published:2025-02-01 Online:2025-02-11

摘要:

【背景】青稞穗腐病仅在青藏高原发生流行,近年来呈加重蔓延态势,成为当地主粮作物青稞(Hordeum vulgare var. nudum)的主要病害之一,对保障青稞高产稳产构成严重威胁。穗螨(Siteroptes spp.)是病原菌禾生指葡孢霉(Dactylobotrys graminicola)初侵染菌源的传播载体,目前病害侵染循环过程尚不清楚,也无有效防治措施。【目的】通过分析穗螨迁移聚集,揭示初侵染菌源传播和侵染青稞幼穗的过程,为制定病害防控技术提供科学依据。【方法】检测穗腐病流行区土壤和青稞样本的穗螨数量变化和分布,显微观察并鉴定穗螨携带真菌的种类和幼穗发病过程,LPCB染色法检测幼穗病斑附近和土壤中穗螨贮孢囊携带的真菌孢子。温室验证穗螨最早侵入幼苗时间和分布,接种青稞组织测定禾生指葡孢霉致病力。【结果】越冬穗螨最早从第1叶片展开形成的喇叭口进入并聚集于叶片基部内侧。青稞植株中87.63%—99.34%穗螨聚集于主茎,仅0.66%—12.37%分布于分蘖。主茎95.48%—99.74%穗螨聚集于心叶基部,孕穗初期30%以上转移至幼穗。主茎穗腐病发生率是分蘖的6.37倍。孕穗初期小穗的稃和芒出现黄绿色水浸状病斑,附近常有成螨停留,贮孢囊携带真菌孢子比例仅为28.57%,显著低于土壤中穗螨带孢比例的46.70%。出苗后土壤中穗螨密度长期维持在较低水平,直至青稞收获后突然升至播种前的2.85倍。88.66%穗螨和76.47%幼穗病斑的真菌分离物为禾生指葡孢霉,该病原菌仅对幼穗具有较强致病力。【结论】越冬穗螨主要在出苗早期从土壤向青稞幼苗迁移聚集,最早从第1叶片展开后形成的喇叭口进入叶基部。超过30%聚集于主茎新生叶的穗螨孕穗初期转移到幼穗,释放病原菌分生孢子引起侵染。禾生指葡孢霉侵染循环由穗螨介导完成,穗腐病主要危害青稞主茎。成熟期病穗中产生大量成螨,导致收获后表层土壤中穗螨密度显著增加。因此,青稞穗腐病是穗螨载体介导的单侵染循环病害。

关键词: 青稞, 穗腐病, 禾生指葡孢霉, 穗螨, 侵染循环, 致病力

Abstract:

【Background】Hulless barley ear (or spike) rot epidemically occurs only in the Qinghai-Xizang Plateau, which has been getting heavier and spreading more widely in recent years. It has become one of the major diseases in the staple food crop, hulless or naked barley (Hordeum vulgare var. nudum), referred to as Qingke in local areas. It seriously threatens the guarantee of high yield and stable production of hulless barley crops. Grass mite (Siteroptes spp.) plays the role of inoculum transmission vector of the pathogen Dactylobotrys graminicola. The disease cycle is still unclear, and a control method is not available at present. 【Objective】In this study, the migration and clustering of grass mites were investigated in order to disclose the processes of pathogen inoculum transmission and the infection of inflorescence of hulless barley. The results obtained here will serve as a scientific basis for developing technologies for ear rot control. 【Method】Variations in the number of mites in samples of surface soil and on hulless barley plants, as well as their distributions, were detected. The fungi carried by grass mites were microscopically observed and isolated for species identification, and the infection processes of hulless barley inflorescences were also detected under a microscope. The fungal spores stored in the sporothecae of grass mite vectors near the lesions of inflorescences and those collected from the soil were tested using the lactophenol cotton blue dyeing method. The initial invasion time of grass mites into hulless barley seedlings and their distribution within the plants were verified in the greenhouse. The pathogen D. graminicola was inoculated onto hulless barley tissues for testing its pathogenicity. 【Result】The overwintering mites initially moved in from the horn-shaped opening of the first leaf after the blade unfolded and gathered at the adaxial side of its basal part. About 87.63%-99.34% of the grass mites found in hulless barley plants were distributed in their main stems, with only 0.66%-12.37% in tillers. The majority of mites in the main stems (95.48%-99.74%) were gathered around the basal parts of young leaves, over 30% of which moved onto inflorescences at the early booting stage. The incidence of ear rot in the main stem was 6.37 times that of the tiller. Greenish yellow, water-soaked lesions appeared on the glumes and awns of young spikelets, and adult mites were usually found near them at the early booting stage; 28.57% of these mites contained fungal spores in their sporothecae, significantly lower than the 46.70% ratio of spore-carrying mites in the soil. After seedling emergence, the mite density in the soil remained at a relatively low level for a long time until hulless barley was harvested, and it abruptly increased by 2.85 times compared to before sowing. About 88.66% of the fungal isolates from grass mites and 76.47% of those from lesion tissues of inflorescences were identified as D. graminicola, and the pathogen was only strongly pathogenic to the inflorescences. 【Conclusion】The overwintering mites mainly migrated from the soil and flocked to hulless barley seedlings during the early stage after plant emergence, first entering the basal part of the first leaf through the horn-shaped opening formed after leaf blade unfolded. Over 30% of mites clustering around the newly born leaves of a main stem subsequently moved onto the inflorescence at the early booting stage and then released D. graminicola spores to cause infection. The disease cycle of D. graminicola was completed with the essential aid of grass mite mediator. Ear rot mainly infected the main stems of hulless barley plants. It was not until at the repining stage that there were plenty of adult mites produced on the diseased ears, resulting in a significant increase in the mite density in surface soil after harvesting. Therefore, ear rot of hulless barley is a monocyclic disease mediated by vector grass mite.

Key words: hulless barley, ear rot, Dactylobotrys graminicola, Siteroptes spp., cycle of infection, pathogenicity