湖南新化多花黃精葉枯病病原鑒定及室內(nèi)毒力測(cè)定?

摘 要：為明確湖南新化多花黃精葉枯病病原菌種類組成及其致病力情況，采用組織分離法對(duì)19份多花黃精葉片病樣進(jìn)行分離、培養(yǎng)和純化，采用形態(tài)學(xué)和分子生物學(xué)方法對(duì)分離菌株進(jìn)行鑒定，并通過離體葉片接種法對(duì)所獲得的菌株進(jìn)行致病力測(cè)定。結(jié)果表明：引起湖南省新化縣多花黃精葉枯病的病原菌為間座殼屬（Diaporthe）的Diaporthe hongkongensis、Diaporthe tulliensis和Diaporthe eres 這3個(gè)種；其中Diaporthe hongkongensis的致病力最強(qiáng)，Diaporthe eres次之，Diaporthe tulliensis的致病力最弱。選取了5種常見藥劑采用生長(zhǎng)速率法對(duì)Diaporthe hongkongensis進(jìn)行室內(nèi)毒力測(cè)定。結(jié)果表明：5種供試藥劑的EC50值大小表現(xiàn)為25%嘧菌酯懸浮劑＞32.5%苯甲–嘧菌酯懸浮劑＞75%百菌清可濕性粉劑＞10%苯醚甲環(huán)唑水分散粒劑＞5%己唑醇懸浮劑，其中對(duì)該病菌毒力最強(qiáng)的殺菌劑為5%己唑醇懸浮劑，其EC50值為8.932 mg/L。綜上所述，湖南新化的多花黃精葉枯病是由間坐殼屬真菌侵染引起的，5%己唑醇懸浮劑、10%苯醚甲環(huán)唑水分散粒劑對(duì)該病菌的殺菌效果較好，可作為防治藥劑。

關(guān)鍵詞：多花黃精；葉枯病；間座殼屬；鑒定；致病力測(cè)定；室內(nèi)毒力測(cè)定

中圖分類號(hào)：S435.672 文獻(xiàn)標(biāo)識(shí)碼：A 文章編號(hào)：1006-060X（2023）04-0061-05

Abstract：This study aims to clarify the pathogen composition of leaf blight of Polygonatum cyrtonema and their pathogenicities in Xinhua County of Hunan Province. Nineteen diseased leaf samples were isolated， cultured and purified by tissue separation method; the isolates were identified by morphological and molecular biological methods; and the pathogenicity of the isolates and their pathogenicity differences were determined by the inoculation method of in vitro leaves. The results showed that the pathogens were Diaporthe hongkongensis， Diaporthe tulliensis and Diaporthe eres of Diaporthe based on morphological characteristics and comparative analysis of gene sequences of 28S rDNA-ITS， β-tubulin and EF-1α. Among them， Diaporthe hongkongensis had the strongest pathogenicity， followed by Diaporthe eres， and Diaporthe tulliensis was the weakest. Thereafter 5 kinds of ordinary fungicides were selected for indoor toxicity test of Diaporthe hongkongensis by the growth rate method. The toxicity test result showed that EC50 values of the five tested agents ranked as azoxystrobin 25% SC gt; difenoconazole-azoxystrobin 32.5% SCgt; chlorothalonil 75% WP gt; difenoconazole 10% WG gt; hexaconazole 5% SC， among which hexaconazole 5% SC had the strongest toxicity to the pathogen， and its EC50 value was 8.932 mg/L. In sum， the leaf blight of Polygonatum cyrtonema in Xinhua County of Hunan Province is caused by infection of Diaporthe. Both hexaconazole 5% SC and" difenoconazole 10% WG" have good control effect on mycelial growth of the pathogen and can be used as control agents.

Key words：Polygonatum cyrtonema; leaf blight; Diaporthe; identification; pathogenicity determination; laboratory toxicity test

多花黃精（Polygonatum cyrtonema）為百合科黃精屬植物，是2020年版《中國(guó)藥典》中中藥黃精的基源植物之一，已有2000 a以上的藥用歷史，俗稱姜形黃精，為中國(guó)藥食同源植物[1]。多花黃精作為藥材時(shí)，以黃精多糖、甾體皂苷為主要有效成分，具有調(diào)節(jié)血糖、增強(qiáng)免疫力、改善記憶以及抗衰老抗炎抗病毒抗腫瘤等作用，臨床上常用于治療冠心病、高血脂、糖尿病、高血壓、慢性支氣管炎、缺血性中風(fēng)等疾病[2-3]。……