菌核病是发生在假丝酵母上的一种严重疾病。对病原真菌物种的透彻了解和生物学特性的了解对于控制菌核病很重要。通过组织分离从Z.念珠菌的病叶中分离出真菌菌株。科赫假说通过健康叶片的致病性筛选致病菌株,包括重新隔离和识别。通过从致病菌株中提取基因组DNA并测量四个位点的核苷酸序列,构建了多基因系统发育树,包括内部转录间隔区(ITS),RNA聚合酶Ⅱ第二大亚基(RPB2),甘油醛-3-磷酸脱氢酶(G3PDH),和热休克蛋白60(HSP60)。通过显微镜分析评估真菌结构的形态特征。观察并记录不同pH下病原菌的生长情况,不同的温度,不同的碳源和不同的氮源来阐明其生物学特性。代表性菌株D7,D13,X4和X15感染了Z.念珠菌并引起菌核病腐烂。在文化的开始,马铃薯葡萄糖琼脂(PDA)培养基上出现白色絮状真菌菌丝,7天后,菌落边缘出现黑色球形至不规则形菌核。菌核的直径为2.4-8.6毫米和0.4-0.9毫米,分别。一个菌核能够从1到5个菌核发芽。Ascus呈圆柱形或纺锤形,尺寸为110.0-120.0×9.2-11.6μm。其中一个含八种无色,椭圆形子囊孢子,尺寸为8.4-12.0×4.5-5.5μm。基于ITS基因序列构建的系统发育树,G3PDH,HSP60和RPB2,D7和D13与菌核病菌核病具有99%的同源性,而X4和X15与微小核盘菌有99%的同源性。当培养温度为15°C-25°C时,菌核菌生长更合适,pH5.0,碳源为麦芽糖,氮源为酵母粉。当培养温度为15°C时,美国次要生长更合适,pH5.0,碳源为葡萄糖,氮源为酵母粉。结果确定病原体为硬核链球菌和小链球菌。据我们所知,本报告首次报道菌核病菌和小型菌核病菌在Z.念珠菌上引起菌核病。本文旨在根据形态特征确定中国念珠菌菌核病的致病因子,分子鉴定,和致病性测试。进行了生物学特性实验,了解疾病的发生规律。我们还评估了有效控制这种疾病的方法。我们的发现为进一步研究盘菌腐烂的发病机制提供了支持。
Sclerotinia rot is a serious disease that occurs on Zephyranthes candida. A thorough understanding of the pathogenic fungal species and understanding the biological characteristics are important for controlling sclerotinia. Fungal strains were isolated from the diseased leaves of Z. candida through tissue isolation. Koch\'s hypothesis screened pathogenic strains by pathogenicity of healthy leaves, including re-isolation and identification. A multigene phylogenetic tree was constructed by extracting genomic DNA from pathogenic strains and measuring the nucleotide sequences at four sites, including the internal transcribed spacer (ITS), RNA polymerase II second largest subunit (RPB2), glyceraldehyde-3-phosphate dehydrogenase (G3PDH), and heat shock protein 60 (HSP60). Morphological characteristics of the fungal structures were evaluated through microscopic analysis. The growth of pathogens was observed and recorded under different pH, different temperatures, different carbon sources and different nitrogen sources to clarify their biological characteristics. Representative strains D7, D13, X4, and X15 infected Z. candida and caused sclerotinia rot. At the beginning of the culture, white flocculent fungal hyphae appeared on the potato dextrose agar (PDA) medium, and black spherical to irregular-shaped sclerotia appeared at the edge of the colony after 7 days. The diameter of the sclerotia was 2.4-8.6 mm and 0.4-0.9 mm, respectively. One sclerotium was able to germinate from 1 to 5 apothecia. Ascus were cylindrical or spindle-shaped, with a size of 110.0-120.0 × 9.2-11.6 μm. One ascus contained eight colorless, oval ascospores, with a size of 8.4-12.0 × 4.5-5.5 μm. Based on the phylogenetic tree constructed with the gene sequences for ITS, G3PDH, HSP60, and RPB2, D7 and D13 shared 99% homology with sclerotinia sclerotiorum, whereas X4 and X15 shared 99% homology with sclerotinia minor. S. sclerotiorum growth was more suitable when the culture temperature was 15°C-25°C, pH 5.0, carbon source was maltose and nitrogen source was yeast powder. S. minor growth was more suitable when the culture temperature was 15°C, pH 5.0, the carbon source was glucose, and the nitrogen source was yeast powder. The results identified the pathogens as S. sclerotiorum and S. minor. To the best of our knowledge, this is the first report of S. sclerotiorum and S. minor causing sclerotinia rot on Z. candida. We herein aimed to identify the causal agent of sclerotinia rot of Z. candida in China based on morphological characteristics, molecular identification, and pathogenicity tests. Performed the experiments on the biological characteristics, to understand the law of disease occurrence. We also evaluated methods for the effective control of this disease. Our findings provide support for further studies on the pathogenesis mechanism of sclerotinia rot.