一种烟草新叶斑病病原菌的鉴定及其生物学特性

打开文本图片集

中图分类号：S432.1 文献标识码：A文章编号：1673-9868（2026）03-0023-09

Identification and Biological Characteristics of a Pathogen of Tobacco New Leaf Spot

CAO Shang1， TAN Ying1， TU Yuhe1， WANG Pingping 2 ，AI Suilong²， WANG Bingang³， SHEN Jian4， WANG Yang 1

1. College of Plant Protection， Northwest A&F University，Yangling Shaanxi 712100，China;

2. Shaanxi Institute of Tobacco Science，Xi'an Shaanxi 710061，China；

3.Long County Branch of Baoji Tobacco Company，Long County Shaanxi 72120o，China;

4. Ningqiang Branch of Hanzhong Tobacco Company，Ningqiang Shaanxi 724400，China

Abstract：To clarify the pathogenic bacteria of a new leaf spot disease of tobacco and its biological characteristics，disease samples were collcted from the tobacco field of Qin Yan 99 in Long County，Baoji. The pathogenic fungi were obtained through isolation， purification and pathogenicity determination. The pathogen was identified by combining morphology and molecular biology，and the biological properties of the representative strain BANl were determined. The results showed that the disease mainly affected tobacco leaf margins and tips，presenting asbrown，serrated or irregularly shaped spots that easily perforated and detached in the later stages. The pathogen colonies on PDA medium were white on the obverse and yellow-brown on the reverse，with an average growth rate of （7.15±0.25）mm/d ， Pycnidia were dark brown，spherical，measuring（141.8—236.2） μm×（190.9-246.6） μm . Conidia were colorless，unicellular，and pike-shaped，with dimensions of （2.4-3.0） ） μm×（3.6-6.8）μm . Multigene sequence analysis based on ITS，LSU ， and TUB2 gene sequences confirmed the pathogen as Phoma bulgarica. Optimal growth conditions included cultivation on PDA medium， pH 5， 25°C ，and total darkness. The optimal carbon and carbon sources were starch and phenylalanine，respectively. The lethal temperature of the pathogen was 46∘C ，aftera water bath for 10min . This is the first report of P . bulgarica causing leaf spot disease on tobacco in China.

Key words： tobacco; leaf spot; identification of pathogenic fungi； biological characterization

近年来，由于耕作制度、气候条件、烟草品种和栽培方式的改变，以及烟田连作年限延长，导致烟草叶斑类病害逐年加重[1]。（剩余8708字）