重楼花叶坏死病毒侵染滇黄精的首次报道

<正>滇黄精(Polygonatum kingianum Coll. et Hemsl)为百合科(Liliaceae)黄精属(Polygonatum)多年生草本植物,属于药食两用资源^[1]。用于补气养阴、健脾、润肺、益肾,现代药理研究发现具有抗氧化、抗病毒、抗肿瘤等作用^[2-3]。近年滇黄精人工种植发展迅速,病虫害问题凸显。2019—2020年在云南曲靖、昆明滇黄精种植基地调查发现滇黄精表现花叶、褪绿、叶片皱缩、植株矮小等症状(图1-A),该病害田间发病较为普遍,不同地块发生率在5%～15%,一些地块出现集中发病现象。为明确病原种类,本研究利用透射电子显微镜观察、转录组测序、序列分析,对侵染滇黄精的病毒进行鉴定。     

日本进境无花果苗中短颈剑线虫的鉴定

短颈剑线虫Xiphinema brevicollum是我国重要的检疫性线虫, 寄生于植物根部, 影响寄主植物长势并降低产量。本文对青岛口岸进境的日本无花果Ficus carica苗中截获的一种剑线虫进行了形态学特征鉴定和分子序列分析, 为口岸进境植物线虫检疫提供参考依据。通过形态特征观察、测计, 以及18S rDNA、ITS1、28S-D2/D3区和线粒体COXⅠ基因序列系统发育分析的方法, 对截获的日本无花果线虫种群进行鉴定。截获的日本无花果线虫种群形态学和分子生物学特征与短颈剑线虫相似, 其主要形态特征为:虫体体型中等, 热杀死后向腹面弯曲呈开螺旋“C”形, 体长1 713.4～1 910.2 μm, 最大体宽35.8～47.1 μm, 两端渐细。唇区圆, 缢缩明显, 侧器囊漏斗状。齿尖针约为齿托长度的1.5倍, 齿托基部呈凸缘状;导环为双环;阴门位于虫体中部, 横裂, 阴道长度占阴门处体宽的1/3左右。生殖管对生, 均发育完全, 生殖管较短, 卵巢先端回折, 子宫内无特殊分化。尾短圆锥形, 背面弯曲, 腹面直, 尾尖钝圆, 尾长24.0～29.5 μm, 等于或略长于肛门处体宽。基于rDNA ITS1区构建的系统进化树, 该截获种群与短颈剑线虫巴西种群、新西兰种群、比利时种群及南非种群聚类成一个独立分支, 序列相似性达98.5%～98.7%;基于线粒体COXⅠ序列构建的系统进化树, 该截获种群与短颈剑线虫5个日本种群聚类成一个独立分支, 序列相似性达91.6%～93.6%。根据形态学和分子生物学特征分析, 此次截获的日本无花果线虫种群为短颈剑线虫, 并首次确认了无花果为该线虫的自然寄主, 海关检疫此类苗木进境时应重点关注该线虫, 降低传入几率。     

First isolation of rose yellow mosaic virus in Japan

Rose yellow mosaic virus, which belongs to the Roymovirus genus in the Potyviridae family, was isolated here in Japan from a rose cultivar, Irish Mist. The full-length genomic sequence was similar to a strain in Minnesota, United States, which was the first ever isolated, with 85% nucleotide and 94% amino acid sequence similarities. Unlike the Minnesota strain, which lacks 220 nt including the 6K1 protein region, the Japanese isolate contains this coding region, which is commonly found in those of the Potyviridae.

     

湖南首次检测到黄瓜绿斑驳花叶病毒

 黄瓜绿斑驳花叶病毒（Cucumber green mottle mosaic virus,CGMMV）自1935年首次报道^［1］以来,已广泛分布于亚洲、欧洲、南美洲的多个国家和地区,对葫芦科作物的生产造成了严重损失。CGMMV主要有两种重要的传播途径,一是带毒种子造成远距离传播,二是授粉、嫁接等农事操作造成的田间传播^［2］。     

Characterization of Lasiodiplodia species causing leaf blight,stem rot and fruit rot of fig (Ficus carica) in Malaysia

Fig (Ficus carica) is an exotic deciduous plant that is grown worldwide. Fungal diseases pose a major threat to fig plants, affecting their fruit quality and production. This study was conducted to characterize the fungal isolates associated with leaf blight, stem rot and fruit rot of F. carica in Malaysia through morphological analysis, DNA sequencing, multigene phylogenetic analysis and pathogenicity tests. From September 2018 to March 2019, 30 blighted leaves and 30 rotted stems and fruits of F. carica were collected from several nurseries in Malaysia. Thirty fungal isolates that belonged to Lasiodiplodia theobromae (27 isolates) and L. brasiliensis (three isolates) were identified based on morphological characteristics, comparison of DNA sequences and phylogenetic analysis of the internal transcribed spacer (ITS), elongation translation factor 1-α (tef1-α), β-tubulin (tub2) and DNA-directed RNA polymerase II subunit (rpb2). Among the 27 isolates of L. theobromae, nine isolates were obtained from leaves, eight isolates from stems and 10 isolates from fruits, whereas the three isolates of L. brasiliensis were obtained from stems (two isolates) and a leaf (one isolate). The results of pathogenicity tests revealed that L. theobromae and L. brasiliensis isolates were responsible for leaf blight and stem rot of F. carica, whereas fruit rot was caused by L. theobromae isolates. The present study highlighted two different species, L. theobromae and L. brasiliensis, as the causal agents of leaf blight and stem rot of F. carica. Additionally, L. theobromae caused fruit rot of F. carica in Malaysia.     

First report of viruses infecting Vigna marina and Vigna riukiuensis in Japan

Journal of General Plant Pathology - Mosaic, chlorosis, brown spots, or roughness were found on Vigna marina and V. riukiuensis, which are salt-resistant wild relatives of cowpea (V. unguiculata)...