山西省‘赞皇大枣’黑腐病病原菌的分离鉴定及生物学特性研究

Isolation,identification and biological characteristics of the pathogen causing black rot disease in 'Zanhuangdazao' jujube of Shanxi province

【目的】明确山西省‘赞皇大枣’黑腐病病原菌种类及其生物学特性。【方法】2011—2013年从山西石楼‘赞皇大枣’种植区采集新鲜‘赞皇大枣’黑腐病果样品,采用组织块法分离和柯赫氏法则回接证病;采用形态学和ITS r DNA分子鉴定相结合的方法鉴定病原菌;采用菌落生长法和血球计数板孢子计量法进行生物学特性研究。【结果】明确了链格孢属细极链格孢(Alternaria tenuissima)是引起‘赞皇大枣’黑腐病的优势病原菌。该菌生长的最适条件为温度28℃,p H 8;最佳碳源葡萄糖,最佳氮源硝酸钠,最佳培养基PDA;光照对菌丝生长无影响。产孢的最适条件为温度28℃,p H 10,不加碳源,最佳氮源硝酸钠,光暗交替有利于产孢。【结论】山西省‘赞皇大枣’黑腐病主要致病菌及其生物学特性的明确,为后续的病原侵染规律和病害防治研究奠定了基础。

【Objective】To clarify the pathogen causing‘Zanhuangdazao'jujube black rot disease andtheir biological characteristics.【Methods】Samples with typical symptoms of the black rot were collectedfrom Shilou County,Shanxi Province from 2011 to 2013. Pathogen was isolated from diseased fruit seg-ments and pathogenicity was tested following Koch's postulate. Identification of the pathogens was madeby morphological study and r DNA molecular identification. Biological characteristics of the pathogen weredetermined by measuring the diameter of the colony and counting the number of conidia using Hemocy-tometer Measurement.【Results】The black rot disease was mainly caused by Alternaria tenuissima. Theoptimum growth conditions for A. tenuissima were as follows: temperature,28 ℃;p H value,8;carbonsource,glucose;nitrogen source,sodium nitrate;medium,PDA. Light had no obvious effect on myceli-al growth. The optimum conditions for the germination of conidia of A. tenuissima were: temperature,28 ℃;p H value,10;without carbon source;nitrogen source,sodium nitrate. The alternation of lightand darkness was helpful to conidium germination.【Conclusion】A. tenuissima is pathogen causing‘Zan-huangdazao'jujube black rot disease in Shanxi Province and the determination of its primary biologicalproperty lays a foundation for further studies in pathogen infection and disease control.