Department of Plant Protection, Rasht Branch, Islamic Azad University, Rasht 4147654919, Iran.
Department of Horticultural Science, Rasht Branch, Islamic Azad University, Rasht 4147654919, Iran.
Cells. 2022 Aug 25;11(17):2643. doi: 10.3390/cells11172643.
Peanut stem white rot caused by Sacc. is a soil-borne disease that is widely prevailing across peanut farms, leading to serious economic losses. Screening for biocontrol agents against this pathogen is urgent. In this research, 166 fungal isolates including 136 isolates of and 30 isolates of antagonistic endophytic fungi were obtained from a total of 220 samples collected from peanut farms in Guilan province, Iran. After morphological and molecular identification, six superior endophytic isolates were finally selected for the in vitro and greenhouse trials, including four isolates from , , , and and two isolates from . Four methods of biocontrol were used during the in vitro phase, i.e., dual culture, volatile metabolites assay, non-volatile metabolites assay (culture extract), and slide culture. It was found that had the highest capability of suppressing the mycelial growth of in the dual culture method (90.98%). As for the volatile metabolites assay, the most effective isolates in inhibiting the pathogen's mycelial growth were (MN395854.1) and (84.30% and 73.50% inhibition, respectively). In the non-volatile metabolites method, the isolates that performed the best in suppressing the mycelial growth of were and (MN395854.1) with 91.80% and 90.20% inhibitory effects, respectively. On the other hand, in the slide culture method, all isolates, except for and , successfully controlled the development of hyphae. The greenhouse trials also supported the effectiveness of endophytic fungi in controlling the pathogen on the host plants. According to the results, , , and (MN395854.1) were 44%, 42%, and 38% effective in alleviating the disease incidence and severity. Moreover, the application of these antagonistic fungi in the greenhouse conditions increased the height, fresh weight, and dry weight of the plants infected with the disease causal agent compared to the plants treated only with the pathogen. The results of the in vitro and greenhouse experiments revealed that the endophytic fungi occurring in the natural microbiota of peanut are capable of bio-controlling , the causal agent of peanut stem white rot disease. These findings shed new insights into the possible resistance induction in plants through biological protection.
花生茎基白腐病是一种由 Sacc.引起的土传病害，广泛流行于花生种植区，导致严重的经济损失。筛选针对该病原菌的生防剂迫在眉睫。本研究从伊朗吉兰省 220 个花生种植区采集的 220 个样本中获得了 166 株真菌分离株，其中包括 136 株 和 30 株拮抗性内生真菌。经过形态学和分子鉴定，最终从内生真菌中选择了 6 株优势内生真菌进行了室内和温室试验，其中 4 株来自 ， 和 ，2 株来自 。在室内阶段采用了 4 种生防方法，即双培养、挥发性代谢物测定、非挥发性代谢物测定（培养提取物）和滑培养。结果表明，在双培养方法中， 对 的抑菌效果最好（90.98%）。挥发性代谢物测定结果显示，对病原菌菌丝生长抑制效果最好的菌株为 （MN395854.1）和 （抑制率分别为 84.30%和 73.50%）。在非挥发性代谢物方法中，抑制 生长效果最好的菌株为 和 （MN395854.1），抑制率分别为 91.80%和 90.20%。另一方面，在滑培养方法中，除 和 外，所有分离株均能有效控制病原菌菌丝的发育。温室试验也支持内生真菌在宿主植物上控制病原菌的有效性。结果表明， 、 、 （MN395854.1）对减轻病害发生率和严重程度的效果分别为 44%、42%和 38%。此外，与仅用病原菌处理的植株相比，在温室条件下应用这些拮抗菌株可提高感染病原菌的 植株的高度、鲜重和干重。室内和温室试验的结果表明，花生天然菌群中的内生真菌能够生物防治花生茎基白腐病的病原菌 。这些发现为通过生物保护诱导 植物产生抗性提供了新的思路。
