貴州省余慶縣茶褐枯病病原菌的鑒定

王雪 王勇 尹橋秀

摘要 為鑒定引起茶褐枯病的病原菌，本研究對(duì)病原菌進(jìn)行分離、純化和培養(yǎng)，通過柯赫氏法則驗(yàn)證菌株的致病性，并觀察病原菌的形態(tài)特征，依據(jù)病原菌rDNA-ITS、ACT、CAL 和TUB2基因進(jìn)行多基因系統(tǒng)發(fā)育分析。結(jié)果顯示：病原菌分生孢子呈淡藍(lán)色，表面光滑，無隔膜，圓柱狀，兩端鈍或向底部變窄，水滴狀斑點(diǎn)，大小為（11.7～29.5）μm×（3.9～7.7）μm，平均為（19.4±4.4）μm×（5.4±0.8）μm，分生孢子梗形成于氣生菌絲上，透明，具有隔膜;附著胞為棒狀等不規(guī)則形狀，顏色呈棕色到深棕色，單生。基于病原菌形態(tài)學(xué)鑒定和多基因系統(tǒng)發(fā)育分析結(jié)果，將病原菌確定為山茶刺盤孢Colletotrichum camelliae。

關(guān)鍵詞 茶褐枯病; 山茶刺盤孢; 形態(tài)特征; 致病性分析; 系統(tǒng)發(fā)育分析

中圖分類號(hào)： S 435.711 ?文獻(xiàn)標(biāo)識(shí)碼： A ?DOI： 10.16688/j.zwbh.2019225

Abstract To identify the pathogen causing tea brown blight disease， we isolated， purified and cultivated the pathogenic fungus from the diseased tea leaves. Its pathogenicity was determined according to Kochs rule， and the morphological characteristics of the pathogen were observed. Phylogenetic analysis of multi-locus sequences， including rDNA-ITS， actin， calmodulin and tubulin 2， was conducted. The results showed that the conidium of the pathogen was hyaline， smooth-walled， aseptate， cylindrical， with obtuse ends or narrowed towards the base， guttulate， （11.7-29.5）μm×（ 3.9-7.7）μm， and the average was （19.4±4.4）μm×（5.4±0.8）μm. Conidiophores were directly formed from aerial mycelia， hyaline， septate. Appressoria were clavate， irregularly shaped， brown to dark brown， and solitary. Based on phylogenetic analyses and morphology， the pathogen was identified as Colletotrichum camelliae.

Key words tea brown blight disease; Colletotrichum camelliae; morphological characteristics; pathogenicity analysis; phylogenetic analysis

茶樹是多年生灌木或喬木，廣泛種植于熱帶、亞熱帶和溫帶地區(qū)。茶樹病害種類較多，對(duì)茶葉的產(chǎn)量和品質(zhì)構(gòu)成一定的影響[1-3]。據(jù)報(bào)道，世界上已有記載的茶樹病原種類多達(dá)500余種，我國已記載的茶樹病害種類有138種[2]。根據(jù)病害在茶樹上的發(fā)生部位，將其分為葉部病害、莖部病害、根部病害和花部病害。其中，茶樹葉部病害的種類相對(duì)其他部位的種類多[2]。同時(shí)，研究發(fā)現(xiàn)，同一種病原菌可侵染茶樹不同的組織部位，引起不同的組織產(chǎn)生病害[4-7]。此外，多種病原菌可復(fù)合侵染引起茶樹病害[8]。2016年至今，陸續(xù)有茶樹新病害和新病原的報(bào)道，例如，擬盤多毛孢Pestalotiopsis camelliae所引起的茶輪斑病[9]，茶擬盤多毛孢P. theae引起的黑褐色葉斑病[10]，莖點(diǎn)霉屬病原菌Phoma segeticola var. camelliae和P. herbarum所引起的茶葉斑病[11-12]，果生刺盤孢Colletotrichum fructicola 所引起的茶炭疽病[13]。……