State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Agric-Environment and Agric-Products Safety, College of Agriculture, Guangxi University, Nanning 530004, China.
Phytopathology. 2024 Mar;114(3):618-629. doi: 10.1094/PHYTO-02-23-0045-R. Epub 2024 Mar 8.
The dynamic of plant-parasitic nematode populations in soil is closely related to soil microorganisms. Fungi from cysts were isolated to explore the phenomenon of decline in the population in the soil. Phylogenetic study of partial ITS, , , and gene sequences, in addition to morphological investigations, was utilized to identify a nematode-destroying fungus. The nematicidal activity of a novel strain GX1 against was assessed in vitro and in the greenhouse. Our findings revealed that strain GX1 is a new species of , named It has a strong parasitic and lethal effect on cysts, with 91.11% parasitism on cysts at 3 days after treatment. The contents of second-stage juveniles (J2s) and eggs inside the cysts were degraded and formed dense vacuoles, and the damaged eggs could not hatch normally. The spore suspension exhibited high nematophagous activity against nematodes, and fermentation filtrate exhibited marked inhibition of egg hatching and nematicidal activities on J2s. The hatching inhibition rates of eggs exposed to 1 × 10 CFU/ml spore suspensions or 20% 1-week fermentation filtrate (1-WF) for 15 days were 98.56 and 100%, respectively. The mortality of J2s exposed to 1 × 10 CFU/ml spore suspension reached 100% at 24 h; exposure to 50% 2-WF was 98.65 and 100% at 24 and 48 h, respectively. Greenhouse experiments revealed that the spore suspension and fermentation broth considerably decreased reproduction by 56.17 to 78.76%. is a potential biocontrol strain with nematophagous and nematicidal activity that deserves attention and application.
土壤中植物寄生线虫种群的动态与土壤微生物密切相关。为了探索土壤中线虫种群减少的现象，从孢囊内分离出真菌。利用部分 ITS、、和基因序列的系统发育研究以及形态学研究，鉴定了一种破坏线虫的真菌。新型菌株 GX1 对的室内和温室杀线虫活性进行了评估。研究结果表明，菌株 GX1 是一新种，命名为。它对线虫的孢囊具有很强的寄生和致死作用，处理后 3 天对孢囊的寄生率达到 91.11%。孢囊内的第二龄幼虫（J2）和卵的含量被降解并形成密集的空泡，受损的卵不能正常孵化。孢子悬浮液对线虫具有很高的捕食活性，发酵滤液对线虫的卵孵化和杀线虫活性具有明显的抑制作用。暴露于 1×10 CFU/ml 孢子悬浮液或 20% 1 周发酵滤液（1-WF）15 天的卵孵化抑制率分别为 98.56%和 100%。暴露于 1×10 CFU/ml 孢子悬浮液的 J2s 在 24 小时内死亡率达到 100%；暴露于 50% 2-WF 的死亡率分别在 24 和 48 小时达到 98.65%和 100%。温室实验表明，孢子悬浮液和发酵液可使繁殖减少 56.17%至 78.76%。是一种具有捕食和杀线虫活性的潜在生防菌株，值得关注和应用。
