Guizhou Academy of Forestry, Guiyang, Guizhou, China.
Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China, Guiyang, Guizhou, China.
Plant Signal Behav. 2023 Dec 31;18(1):2293405. doi: 10.1080/15592324.2023.2293405. Epub 2023 Dec 17.
Similar to other orchid species, (Lindl.ex Hook.) Stein, relies on nutrients provided by mycorrhizal fungus for seed germination and seedling development in the wild owing to a lack of endosperm in its seeds. Therefore, obtaining suitable and specialized fungi to enhance seed germination, seedling formation, and further development is considered a powerful tool for orchid seedling propagation, reintroduction, and species conservation. In this study, we investigated the diversity, abundance, and frequency of endophytic fungal strains in the root organs of . One family and five genera of the fungi were isolated and identified through rDNA-ITS sequencing. The ability of isolated fungi to germinate from the seeds of this species was evaluated, and the development of protocorm has been described. The findings showed that the treatments inoculated with endophytic fungal DYXY033 may successfully support the advanced developmental stage of seedlings up to stage 5. In addition, scanning electron microscopy (SEM) revealed that the mycelium of this strain began to invade from either end of the seeds up to the embryo, extending rapidly from the inside to the outside. Its lengthening resulted in the bursting of the seed coat to form protocorms, which developed into seedlings. The results showed that DYXY033 has a high degree of mycobiont specificity under symbiotic seed germination conditions and is a representative mycorrhizal fungus with ecological value for the species. In summary, this strain may particularly be significant for the protection of species that are endangered in China. In the long run, it may also contribute to global efforts in reintroducing orchid species and in realizing restorations of threatened orchid populations.
类似于其他兰花物种，(Lindl.ex Hook.) Stein 由于其种子中缺乏胚乳，在野外依赖菌根真菌提供的营养物质来促进种子萌发和幼苗发育。因此，获得合适和专门的真菌来增强种子萌发、幼苗形成和进一步发育被认为是兰花幼苗繁殖、再引入和物种保护的有力工具。在这项研究中，我们调查了. 的根器官中内生真菌菌株的多样性、丰度和频率。通过 rDNA-ITS 测序，分离和鉴定了一个真菌科和五个属的真菌。评估了分离真菌从该物种的种子中萌发 的能力，并描述了 原球茎的发育。研究结果表明，用内生真菌 DYXY033 处理可能成功地支持幼苗的高级发育阶段达到第 5 阶段。此外，扫描电子显微镜（SEM）显示，该菌株的菌丝从种子的两端开始侵入，直到胚胎，从内部迅速向外延伸。其伸长导致种皮爆裂形成原球茎，然后发育成幼苗。结果表明，DYXY033 在共生种子萌发条件下具有高度的菌根特异性，是一种具有生态价值的代表菌根真菌，对该物种具有保护意义。总之，该菌株可能对保护中国濒危的 物种特别重要。从长远来看，它也可能有助于全球重新引入兰花物种和实现受威胁的兰花种群的恢复。
