Neospermospora avenae strain:VPRI 42798 Genome sequencing and assembly. Neospermospora avenae strain:VPRI 42798

Spermospora avenae causes the economically important red leather leaf disease of oats, which reduced grain yield and hay quality. It was first reported in the USA in the 1936 and subsequently in Australia in 1978. Despite this, its phylogenetic placement is unknown, attributed merely to Ascomycota. Twenty-three S.avenae single spore isolates were obtained from affected crops in South Australia and western Victoria from 2009-2016. DNA was extracted from each sequenced using Illumina technology. To identify its closest relatives, a draft genome was denovo assembled and contigs with the highest depth, hypothesised to the be the rRNA gene region, were compared to NCBI using the BLASTN function. Contigs that had homologous sequence to the rRNA gene region were used to identify closely related species, which turned out to be Rhynchosporium species. Sequence data from the alpha-tubulin, beta-tubulin, and ITS gene regions of Rhynchosporium species, identified as phylogenetically informative for this genus, were mapped to the S. avenae contigs. Phylogenetic analysis of the ITS region and multilocus concatenation demonstrated that S. avenae is nested within Rhynchosporium , closely related to R. orthosporum and R. lolii . When ITS sequences from other related genera sourced from GenBank were added to the analysis, it appears that Rhynchosporium is paraphyletic and should be split into two genera. Culturally, S. avenae prefers a semi-solid low nutrient medium (ie. quarter strength PDA made with 1.25% agar) and cool temperature (optimum 15 0 C). This corresponds well with the cold wet seasonal conditions required for disease development in the field.

燕麦平脐蠕孢（Spermospora avenae）是引发具有重要经济危害性的燕麦红皮革叶病的致病菌，该病害会降低谷物产量与干草品质。该菌于1936年首次在美国被报道，随后于1978年在澳大利亚被发现。尽管如此，其系统发育分类位置至今尚未明确，仅被暂归为子囊菌门（Ascomycota）。2009年至2016年间，研究人员从南澳大利亚州及维多利亚州西部的染病作物中分离得到23株燕麦平脐蠕孢单孢菌株。从每株菌株中提取DNA，并采用Illumina测序技术进行测序。为明确其近缘类群，研究人员对基因组草图进行了从头（de novo）组装，并将测序深度最高、被推测为核糖体RNA（rRNA）基因区域的重叠群（contigs）通过BLASTN工具与国家生物技术信息中心（NCBI）数据库进行序列比对。研究人员利用与rRNA基因区域存在同源序列的重叠群筛选近缘物种，结果发现其近缘类群为喙孢霉属（Rhynchosporium）物种。将已被证实对喙孢霉属具有系统发育解析价值的α-微管蛋白、β-微管蛋白及内部转录间隔区（Internal Transcribed Spacer, ITS）基因区域的序列数据，比对至燕麦平脐蠕孢的重叠群序列。对ITS区域及多基因串联序列的系统发育分析表明，燕麦平脐蠕孢嵌套于喙孢霉属中，与R. orthosporum和R. lolii亲缘关系紧密。当将从GenBank（基因银行）获取的其他相关属的ITS序列加入分析后，结果显示喙孢霉属为并系群，应被划分为两个属。在培养特性方面，燕麦平脐蠕孢偏好半固体低营养培养基（即采用1.25%琼脂配制的1/4强度马铃薯葡萄糖琼脂（Potato Dextrose Agar, PDA）培养基）及低温环境，最适生长温度为15℃。这与该病害在田间发生所需的冷湿季节条件高度契合。