Jiang Ning, Liang Ling-Yu, Tian Cheng-Ming
The Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China Beijing Forestry University Beijing China.
MycoKeys. 2020 May 14;67:19-32. doi: 10.3897/mycokeys.67.51133. eCollection 2020.
Chinese chestnut () is an important crop tree species in China. However, branch canker and fruit rot are two kinds of severe diseases, which weaken the host and decrease chestnut production. During our investigations into chestnut diseases in China, several fungi have been confirmed as casual agents in previous studies, namely , , , and . In this study, a new canker pathogen is introduced based on morphology, phylogeny and pathogenicity. Typical canker sign of wide, orange tendrils emerging from hosts' glaucous lenticels were obvious on the diseased trees in the field. Symptomatic branches or bark on stems from different chestnut plantations were sampled and isolated, then strains were identified by comparisons of DNA sequence data for the nuclear ribosomal internal transcribed spacer (ITS), partial translation elongation factor-1α () and β-tubulin () gene regions as well as morphological features. As a result, these strains appeared different from any known species. Hence, we propose a novel species named . Pathogenicity was further tested using the ex-type strain (CFCC 52286) and another strain (CFCC 52288) on both detached branches and 3-year-old chestnut seedlings. The inoculation results showed that is mildly pathogenic to Chinese chestnut. However, further studies are required to confirm its pathogenicity to the other cultivated species in America, Europe and Japan.
板栗（）是中国一种重要的经济树种。然而，枝枯病和果实腐烂病是两种严重病害，会削弱寄主并降低板栗产量。在我们对中国板栗病害的调查中，先前的研究已证实几种真菌为致病因子，即，，，和。在本研究中，基于形态学、系统发育学和致病性引入了一种新的枝枯病病原菌。在田间患病树上，典型的从寄主灰白色皮孔中长出宽的橙色卷须的枝枯病症状很明显。从不同板栗种植园采集有症状的枝条或茎干树皮进行分离，然后通过比较核糖体内部转录间隔区（ITS）、部分翻译延伸因子-1α（）和β-微管蛋白（）基因区域的DNA序列数据以及形态特征来鉴定菌株。结果，这些菌株与任何已知的物种都不同。因此，我们提出一个新物种，命名为。使用模式菌株（CFCC 52286）和另一个菌株（CFCC 52288）对离体枝条和3年生板栗幼苗进一步进行致病性测试。接种结果表明对板栗有轻度致病性。然而，需要进一步研究以确认其对美国、欧洲和日本其他栽培的物种的致病性。
