草果三种真菌性叶部病害病原鉴定及生物学特性测定

Pathogen identification and biological characteristics of fungal leaf disease of Amomum tsaoko Crevost et Lemarie

【目的】明确云南省草果(Amomum tsaoko Crevost et Lemarie)3种叶部病害病原菌及其生物学特性,为草果叶斑病的防控提供理论依据。【方法】研究云南省怒江州草果种植基地内发现的3种真菌性病害,通过单孢分离培养获得CG-N01、CG-N02、CG-N03 3个菌株,分别测定其致病性,根据形态特征观察孢子形态,依据多基因序列分析(rDNA-ITS、LSU、tub2和tef-1α)的系统发育树对病原菌进行鉴定,并测定其生物学特性。【结果】菌株CG-N01、CG-N02、CG-N03形态分别符合梨孢属(Pyricularia costina)、茎点霉属(Phoma matteuciicola)、炭疽属(Colletotrichum simmondsii)种属典型特征;菌株CG-N01的rDNA-ITS、LSU和tef-1α的序列长度分别为489、901、475 bp(登录号分别为MN596209、MN689811和MN696687),菌株CG-N02的rDNA-ITS、LSU和tef-1α的序列长度分别为517、997、529 bp(登录号MN596212、MN650644和MN696686),菌株CG-N03的rDNA-ITS、tub2和tef-1α的序列长度分别为560、926、738 bp(登录号MN596210、MN650645和MN696688);纯化病原菌株分别与梨孢属(P.costina)、茎点霉属(P.matteuciicola)和炭疽属(C.simmondsii)具较高同源性。生物学特性测定表明,菌株CG-N01在温度28℃、光照黑暗交替、pH 6.0条件下有利于菌丝生长和分生孢子形成;菌株CG-N02和CG-N03在温度25℃、光照黑暗交替、pH 8.0条件有利于产孢。【结论】本研究首次报道炭疽属(C.simmondsii)可侵染草果植株并引起草果炭疽病,并对草果叶斑病、叶瘟病和炭疽病病原物进行生物学特性测定,为草果病害的多样性研究和田间有效防治提供科学依据和理论支撑。

【Objective】This paper aimed to study the pathogen and biological characteristics of three leaf diseases of Amomum tsaoko Crevost et Lemarie in Yunnan province, and to provide theoretical basis for the control of leaf spot of A.tsaoko. 【Method】Three fungal diseases were discovered from A.tsaoko plantation in Nujiang Prefecture, Yunnan province. Three strains, including CG-N01, CG-N02 and CG-N03 were obtained by single spore culture, their pathogenicity was determined, spore morphology was observed according to morphological characteristics, and pathogen was identified by phylogenetic tree constructed by multi-gene sequence analysis(rDNA-ITS, tub2, LSU and tef-1 α), and biological characteristics were determined. 【Result】The morphological characteristics of CG-N01, CG-N02 and CG-N03 were in accordance with the typical characters of Pyrus costina, Phoma matteuccola and Colletotrichum mondsii, respectively. The rDNA-ITS, LSU and tef-1 α sequences of CG-N01 were 489, 901 and 475 bp, respectively(the login numbers were MN596209, MN689811 and MN696687, respectively);The rDNA-ITS, LSU and tef-1 α sequences of the strain CG-N02 were 517, 997 and 529 bp respectively(the login numbers were MN596212, MN650644 and MN696686, respectively);The rDNA-ITS, tub2 and tef-1 α sequences of strain CG-N03 were 560, 926 and 738 bp, respectively(the login numbers were MN596210, MN650645 and MN696688, respectively). Purified strains of CG-N01, CG-N02 and CG-N03 had high homology with P. costina, P. matteuccola and C. simmondsii, respectively.Biological determination showed that strain CG-N01 was advantageous to mycelium growth and conidia formation under the conditions of 28 ℃, alternating light and dark, and pH 6.0. Strains CG-N02 and CG-N03 were favorable for sporulation at 25 ℃, alternating light and darkness, and pH 8.0. 【Conclusion】This study first reported that C. simmondsii can infect and cause Colletotrichum gloeosporioides, the biological characteristics of the pathogens of leaf spot, leaf blast and anthracnose were determined to provide scientific basis and theory support for the diversity study and effective control of the disease.