利用液化澱粉芽孢桿菌Ba01防治馬鈴薯瘡痂病菌

Abstract

馬鈴薯瘡痂病(Potato common scab)主要由土傳性放線菌馬鈴薯瘡痂病菌(Streptomyces scabies)引起，是近年來影響台灣馬鈴薯產業甚鉅的細菌性病害。然而目前尚無有效殺菌劑及缺乏抗病植株，而輪作等方法亦無法有效降低病害發生，因此希望使用生物製劑成為替代的防治方法。本研究利用分離自台灣田間健康馬鈴薯之液化澱粉芽孢桿菌(Bacillus amyloliquefaciens) Ba01來拮抗馬鈴薯瘡痂病菌。在培養基對峙培養及掃描式電子顯微鏡的實驗中，發現Ba01能有效抑制馬鈴薯瘡痂病菌之生長分化及產孢。經由影像質譜儀分析，發現三種可能的抑菌物質，分別為surfactin、iturin A和fengycin。在溫室的盆栽實驗中，馬鈴薯的罹病度由55.6 ± 11.1% (只接種馬鈴薯瘡痂病菌) 降至4.2 ± 1.4% (同時接種馬鈴薯瘡痂病菌和澆灌Ba01)。而在田間試驗中，馬鈴薯的罹病度也由14.4 ± 2.9% 降至5.6 ± 1.1%，顯示Ba01有望發展成抗馬鈴薯瘡痂病之生物防治製劑。

Potato common scab, which is caused by soil-borne Streptomyces species, is a severe plant disease that results in significant reduction in the economic value of potatoes worldwide. Due to the lack of efficacious pesticides, crop rotations, and resistant potato cultivars against the disease, we investigated whether biological control can serve as an alternative approach. In this study, multiple Bacillus species were isolated from healthy potato tubers, and Bacillus amyloliquefaciens Ba01 was chosen for further analyses based on its potency against the potato common scab pathogen Streptomyces scabies. Ba01 inhibited the growth and sporulation of S. scabies and secreted secondary metabolites such as surfactin, iturin A, and fengycin with potential activity against S. scabies as determined by imaging mass spectrometry. In pot assays, the disease severity of potato common scab was decreased from 55.6 ± 11.1% (inoculated with S. scabies only) to 4.2 ± 1.4% (inoculated with S. scabies and Ba01). In the field trial, the disease severity of potato common scab was reduced from 14.4 ± 2.9% (naturally occurred) to 5.6 ± 1.1% after Ba01 treatment, representing the first documented instance that Bacillus species controls potato common scab in nature.