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荷花腐败病发生普遍,对荷花生产危害巨大,已成为制约中国荷花产业持续发展的重要障碍。为明确中国荷花腐败病菌(Fusarium commune)的生物学特性及遗传分化情况,本文采用藕块接种法对采自广东、湖南、湖北3个不同地区的病原菌进行致病性测定,研究了不同温度、pH、碳氮源对病原菌菌丝生长的影响,同时利用rDNA IGS基因序列对采自不同地区的荷花腐败病菌株进行了系统发育分析。结果表明,荷花腐败病菌对温度、pH等适应范围广,温度在15~35℃,pH4~9均能生长,最适生长温度为25℃,最佳pH值为7,且能利用多种碳氮源。不同的碳源中,蔗糖和葡萄糖较适合该菌的生长;在供试氮源中,菌丝在蛋白胨的基础培养基上生长最快,在尿素的基础培养基上生长最慢;当温度为15、20、30或35℃时,湖北的菌株平均菌落直径最大;当pH值为4.0~5.0时,广东菌株的平均菌落直径较大,当pH值为7.0~9.0时,来自湖北的菌株菌落直径最大。不同地区的病原菌间致病力存在一定差异,基于rDNA IGS的系统发育分析表明,不同地区的病原菌株间存在一定的遗传分化,其中广东菌株与湖南菌株亲缘关系较近(同源性高达99.7%),遗传距离为0.003;而广东菌株与湖北菌株的亲缘关系较远(同源性为97.3%),遗传距离为0.027。
The common occurrence of rotten flower of lotus flower and great harm to the production of lotus flower have become an important obstacle to the sustainable development of Chinese lotus flower industry. In order to clarify the biological characteristics and genetic differentiation of Fusarium commune in China, pathogenicity of three pathogenic bacteria collected from Guangdong, Hunan and Hubei were studied by lotus root inoculation method. The effects of temperature, pH and carbon and nitrogen sources on the mycelial growth of pathogenic bacteria, and phylogenetic analysis of the pathogenic bacteria mycelia from different regions were carried out by using rDNA IGS gene sequences. The results showed that the spoilage bacteria could adapt to a wide range of temperature and pH. The temperature ranged from 15 to 35 ℃ and the pH ranged from 4 to 9. The optimal growth temperature was 25 ℃, the optimum pH was 7, Nitrogen source. Among the different carbon sources, sucrose and glucose were more suitable for the growth of the bacteria. In the nitrogen sources tested, the mycelium grew fastest on the peptone basal medium and the slowest on the urea basal medium. When the temperature was At 15, 20, 30 or 35 ℃, the average colony diameter of Hubei strains was the largest. When the pH value was 4.0-5.0, the average colony diameter of Guangdong strains was larger. When the pH was 7.0-9.0, The largest diameter. Phylogenetic analysis based on rDNA IGS showed that there were some genetic differentiation among pathogenic strains in different regions, among which the Guangdong strains had close genetic relationship with Hunan strains (the homology was as high as 99.7% ), And the genetic distance was 0.003. The genetic relationship between Guangdong strain and Hubei strain was farther (97.3% homology) and the genetic distance was 0.027.