ABSTRACT

A batch of nematophagous fungi (NF), isolated from soil and animal faeces at Tapachula, Chiapas, Mexico, was identified through morphological methods and molecular tools. Additionally, the fungi were biologically characterised through their in vitro predatory capability against the free-living nematode Panagrellus redivivus. Molecular identification of nine isolates was achieved by amplifying the 18S, 5.8S and 28S regions using ITS5 and ITS4 oligonucleotides, followed by sequencing and aligning through BLAST. Only species of Arthrobotrys genus: A. oligospora, A. conoides, A. arthrobotryoides and A. musiformis were found. The in vitro bioassay revealed a large variability in the predatory capabilities of the different isolates. The isolate Z1-1-2 of A. arthrobotryoides showed the highest nematode reduction (NR) from 822.8 (± 169.5) to only 51.4 (± 35.2) = 93.7% NR; in contrast A. oligospora (isolate Z3-2-2) showed the lowest NR from 548.5 (± 66.6) to 234.2 (± 123.6) = 57.2% Genotyping analysis corroborated the morphological identification. The comparison of sequences with the NCBI sequences showed a close phylogenetic relationship. A phylogenetic tree was generated to compare its phylogenetic relationship with other strains reported in the NCBI. The NF isolated could be potential candidates for future studies on the biological control of nematodes.

摘要

通过形态学方法和分子工具鉴定了从墨西哥恰帕斯州塔帕丘拉的土壤和动物粪便中分离出的一批食线虫真菌 (NF)。此外，这些真菌的生物学特征是通过它们对自由生活的线虫Panagrellus redivivus 的体外捕食能力。通过使用 ITS5 和 ITS4 寡核苷酸扩增 18S、5.8S 和 28S 区域，然后通过 BLAST 进行测序和比对，实现了九个分离株的分子鉴定。仅发现节肢植物属的物种：A. oligospora、A. conoides、A. artrobotryoides和A. musiformis 。体外_生物测定显示不同分离株的捕食能力存在很大差异。A. arthrobotryoides的分离株 Z1-1-2显示出最高的线虫减少量 (NR)，从 822.8 (± 169.5) 到仅 51.4 (± 35.2) = 93.7% NR；相比之下，A. oligospora（分离株 Z3-2-2）的 NR 最低，从 548.5 (± 66.6) 到 234.2 (± 123.6) = 57.2% 基因分型分析证实了形态学鉴定。序列与NCBI序列的比较显示出密切的系统发育关系。生成系统发育树以比较其与 NCBI 中报道的其他菌株的系统发育关系。分离的 NF 可能是未来线虫生物控制研究的潜在候选者。