洪小雨 李敏 弓德强 高兆银 杨衍 王义 胡美姣

摘  要：豇豆是海南最主要的冬季瓜菜之一。2019年，调查发现豇豆贮运期间出现一种严重的软腐病。通过病原菌分离、致病性测定、形态学观察和分子生物学鉴定，鉴定该病原菌为瓜果腐霉[Pythium aphanidermatum （Edson） Fitzp.]。采用生長速率法对该病原菌生物学特性进行初步研究。结果表明：该菌菌落适宜生长温度范围为30～35 ℃，最适生长温度为35 ℃，菌落致死温度为50 ℃、10 min;适宜生长的pH为7.0～9.0，最适pH为9.0;最适碳源为可溶性淀粉;最适氮源为蛋白胨;不同光照条件对菌落生长没有显著影响。本研究首次报道瓜果腐霉（P. aphanidermatum）引起豇豆的采后病害。

关键词：豇豆;瓜果腐霉;鉴定;贮藏期;生物学特性

中图分类号：S643.4;S435.2      文献标识码：A

Identification and Biological Characteristics of the Pathogen Causing Postharvest Decay of Cowpea

HONG Xiaoyu1， LI Min1， GONG Deqiang1， GAO Zhaoyin1， YANG Yan2， WANG Yi3， HU Meijiao1*

1. Environment and Plant Protection Institute， Chinese Academy of Tropical Agricultural Sciences / Key Laboratory of Integrated Pest Management on Tropical Crops， Ministry of Agriculture and Rural Affairs， Haikou， Hainan 571101， China; 2. Tropical Crops Genetic Resources Institute， Chinese Academy of Tropical Agricultural Sciences， Haikou， Hainan 571101， China; 3. School of Life and Pharmaceutical Sciences， Hainan University， Haikou， Hainan 570228， China.

Abstract： Cowpea is one of the most important winter vegetables in Hainan. The postharvest decay was occasionally found during storage of cowpea in 2019. The pathogen was confirmed to be Pythium aphanidermatum （Edson） Fitzp. based on cultural features， pathogenicity， morphological characteristics and molecular identification. In this study， the biological characteristics of P. aphanidermatum were preliminarily studied by the mycelium growth rate method. The results showed that the suitable temperature was 30 ℃ to 35 ℃， and the optimum temperature was 35 ℃. The lethal temperature was 50 ℃ for 10 min. The suitable pH value was 7.0 to 9.0， and the optimum pH value was 9.0. The optimal carbon source and nitrogen source were starch and peptone， respectively. Different light had no effect on the colony growth. To our knowledge， this is the first report of P. aphanidermatum caused postharvest decay of cowpea in China.

Keywords： cowpea; Pythium aphanidermatum; identify; storage; biological characteristics

DOI： 10.3969/j.issn.1000-2561.2021.04.028

豇豆（Vigna unguiculata）是豆科豇豆属的耐热性蔬菜[1]，为海南最主要的冬季瓜菜之一。由于海南气候炎热，田间病虫害发生严重，对豇豆产量和农民经济收入造成严重影响。目前，对豇豆田间病害有较多报道，Adegbite等[2]报道瓜果腐霉（Pythium aphanidermatum）可引起豇豆苗期茎腐，造成严重减产;Falade等[3]和Smith等[4]研究发现炭疽菌（Colletotrichum dematium）可侵染豇豆根部，引起植株倒伏，致使豇豆产量下降;毛勇等[5]也在调查中发现瓜果腐霉（P. aphanidermatum）可引起豇豆茎腐;司凤举等[6]发现豆类煤污尾孢菌（Cercospora vignae）可引起豇豆叶片逐渐变黄、脱落，致使植株早衰，采收期缩短，鲜荚产量降低;程晓东[7]在研究中发现豇豆单孢锈菌（Uromyces vignae）可引起豇豆植株发生锈病，导致植株中后期叶片枯黄脱落，有时还引起豆荚病变，严重时植株体内水分大量流失。Emechebe[8]和Suleiman[9]发现瓜果腐霉是豇豆苗期最重要的病原菌，可造成豇豆幼苗茎基和根部快速腐烂软化，从而导致豇豆幼苗大面积死亡。……