Department of Crop Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, PO Box 34, Al-Khoud, 123, Oman.
Sci Rep. 2019 Aug 2;9(1):11255. doi: 10.1038/s41598-019-47736-x.
Pythium-induced damping-off disease is a major disease limiting cucumber and tomato production in different parts of the world. The current study investigated the efficiency of Talaromyces variabilis and its bioactive metabolites in suppressing Pythium-induced damping-off of cucumbers and tomatoes. T. variabilis inhibited the in vitro growth of P. aphanidermatum in solid and liquid media. In addition, abnormalities in P. aphanidermatum hyphae were observed as a result of T. variabilis. Extracts from T. variabilis induced cellular leakage and suppressed oospore production of P. aphanidermatum. Biochemical analyses of T. variabilis metabolites showed that T. variabilis produces glucanase, cellulase and siderophores, suggesting the contribution of these metabolites in the inhibition of P. aphandermatum growth and in hyphal abnormalities. Treating cucumber seeds with spore and mycelial suspension of T. variabilis isolates led to a significant improvement in the seedling survival of P. aphanidermatum-inoculated seedlings from 18 to 52% (improvement by 34%) for isolate 48 P and from 30-66% (improvement by 36%) for isolate 28 R. Similarly, treating tomato seeds with spore and mycelial suspension of T. variabilis isolates led to a significant improvement in the seedling survival of P. aphanidermatum-inoculated seedlings from 7 to 36% (improvement by 29%) for isolate 28 R and from 20 to 64% (improvement by 44%) for isolate 48 P. Differences in the percent improvement in seedling survival between experiments may be related to difference in the efficacy of the two different isolates or their interaction with the hosts and pathogen. The use of T. variabilis in the biocontrol of Pythium-induced diseases may offer alternatives to the currently used chemical control.
腐霉引起的猝倒病是限制世界不同地区黄瓜和番茄生产的主要病害。本研究调查了塔宾曲霉及其生物活性代谢物抑制腐霉引起的黄瓜和番茄猝倒病的效率。塔宾曲霉在固体和液体培养基中抑制腐霉的体外生长。此外，观察到腐霉菌丝的异常是由于塔宾曲霉的结果。塔宾曲霉提取物诱导细胞渗漏，并抑制腐霉的卵孢子产生。塔宾曲霉代谢物的生化分析表明，塔宾曲霉产生葡聚糖酶、纤维素酶和铁载体，表明这些代谢物在抑制腐霉生长和菌丝异常中发挥作用。用塔宾曲霉分离株的孢子和菌丝悬浮液处理黄瓜种子，可显著提高腐霉接种幼苗的种子存活率，从 18%提高到 52%（提高 34%），对 48 P 分离株，从 30%提高到 66%（提高 36%），对 28 R 分离株。同样，用塔宾曲霉分离株的孢子和菌丝悬浮液处理番茄种子，可显著提高腐霉接种幼苗的种子存活率，从 7%提高到 36%（提高 29%），对 28 R 分离株，从 20%提高到 64%（提高 44%），对 48 P 分离株。试验间种子存活率提高百分比的差异可能与两个不同分离株的功效差异或它们与宿主和病原体的相互作用有关。塔宾曲霉在腐霉病生物防治中的应用可能为目前使用的化学防治提供替代方法。
