College of Forestry and Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
The Connecticut Agricultural Experiment Station Valley Laboratory, Windsor 06095; and Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University.
Plant Dis. 2018 Mar;102(3):500-506. doi: 10.1094/PDIS-07-17-1032-RE. Epub 2018 Jan 2.
Chinese fir (Cunninghamia lanceolata) is a significant timber species that has been broadly cultivated in southern China. A shoot blight disease on Chinese fir seedlings was discovered in Fujian, China and a fungus was then consistently associated with the symptoms. This fungus was determined to be causing this disease, among others by fulfilling Koch's postulates. Based on morphological characteristics and multilocus phylogenetic analyses with the sequences of the internal transcribed spacer, partial glyceraldehyde-3-phosphate dehydrogenase gene, partial translation elongation factor 1-α gene, and partial 28S large subunit ribosomal RNA gene, the fungus was identified as Bipolaris oryzae. These characteristics and phylogenetic analyses clearly support that this pathogen is different from B. sacchari, which was, until now, considered to be the causal agent of a similar blight on Chinese fir in Guangdong, China. The fungus was also shown to be strongly pathogenic to rice, one of the most susceptible hosts to B. oryzae. Crop rotation involving rice is often carried out with Chinese fir in southern China, a practice that most likely increases the risk of shoot blight on C. lanceolata. To our knowledge, shoot blight caused by B. oryzae is reported for the first time in a gymnosperm species.
杉木（Cunninghamia lanceolata）是中国南方广泛种植的重要木材树种。在中国福建发现了杉木幼苗梢枯病，随后一直与症状相关的一种真菌。通过满足柯赫氏假设，该真菌被确定为引起这种疾病的原因之一。基于形态特征和多基因座系统发育分析，包括内转录间隔区、部分甘油醛-3-磷酸脱氢酶基因、部分翻译延伸因子 1-α 基因和部分 28S 大亚基核糖体 RNA 基因的序列，该真菌被鉴定为稻双极霉。这些特征和系统发育分析清楚地表明，该病原菌与 B. sacchari 不同，B. sacchari 以前被认为是中国广东类似的杉木梢枯病的病原体。该真菌对水稻的致病性也很强，水稻是对稻双极霉最易感的宿主之一。在中国南方，经常与水稻进行轮作，这很可能增加了杉木梢枯病的风险。据我们所知，由稻双极霉引起的梢枯病是首次在裸子植物中报道。
