枯草桿菌Bacillus subtilis WG6-14對水稻秧苗之生長促進及對Sclerotium rolfsii所造成水稻秧苗立枯病之防治效果

Growth Promotion and Reduced Sclerotium rolfsii Seedling Blight of Rice by Bacillus subtilis WG6-14

林漢釗(H. C. Lin) ； 黃文的(W. D. Huang) ； 楊尚書(S. S. Yang) ； 曾德賜(D. S. Tzeng)

《植物病理學會刊》 17卷1期 (2008/03) Pp. 53-64

https://doi.org/10.6649/PPB.200803_17(1).0006

摘要

本文旨在探討枯草桿菌(Bacillus subtilis WG6-14)於水稻(Oryza sativa L)育苗過程病害管理之應用性。利用本研究室所建立技術以750公升發酵槽所產出之WG6-14醱酵菌液（每毫升約含1×10^10內生孢子），以50~100倍稀釋浸漬處理台稉八號(cv. TK8)稻種，溫室試驗證實，其較之慣行利用撲克拉（25%乳劑，經2000倍稀釋應用）行浸種處理，有提早發芽且明顯提高發芽率的效果。繼而於台中市南屯區產銷班育苗場，以50倍稀釋WG6-14醱酵菌液同法分別浸漬處理台稉八號與台稉九號(cv. TK9)稻種亦發現，其與利用撲克拉(cv. TK8)或利用清水(cv. TK9)行浸種處理之對照組相較，處理兩週後調查結果顯示，兩供試品種發芽率分別提升50 (TK8)與22% (TK9)，秧苗生長則分別提高10與13%。針對Sclerotium rolfsii在秧苗上之危害，經由對峙培養證實WG6-14可產生對S. rolfsii NTSR-01菌株具優異生長抑制效果之抗生物質，於WG6-14培養過濾液處理下，可造成後者菌絲細胞膜滲漏作用。於田間選取已被S. rolfsii感染的秧苗盤，以稀釋50倍之WG6-14每日一次連續澆灌一週，處理後三天，相對於對照組發病面積平均增加年4.92%，WG6-14處理組只增加約0.88%，被害部位菌核形成數最亦大爲減少。在密閉培養皿中，以WG6-14連同尿素一起處理，對存在於未經滅菌處理土壤中之S. rolfsii NTSR-01菌核可有明顯協力致死效果，單獨施用尿素時菌核存活率僅降至56.8%，而WG6-14與尿素共同施用則可導致菌核接近全數死亡。上述結果顯示枯草桿菌WG6-14生物製劑於水稻秧苗生產及苗期立枯病之防治上極具應用潛力。

關鍵字

枯草桿菌WG6-14 ； 生物殺菌劑 ； 生物防治 ； 電解質滲漏 ； 水稻秧苗立枯病 ； 白絹病菌

並列摘要

The application of Bacillus subtilis WG6-14 on seedling production of rice (Oryza sativa L.) was explored. In greenhouse test, the application of a fermentor produced WG6-14 broth culture (contains approximately 1.0×10^10 endospores/ml) at 50-100X in dilution compared to that by Prochloraz (EC, applied at 2000X dilution) as control treatment for seed soaking was shown resulted an earlier and increased seed germination and the increased hypocotyl growth. The germination and growth stimulation was further demonstrated in a followed field trial in a commercial rice seedling propagation station in 2005 at Nan-tun, Taichung. The soaking treatment of rice (cv. TK8 and cv. TK9) with WG6-14 at 50X in dilution led to a 50% (cv. TK8) and 22% (cv. TK9) increase of seed germination and a 10% and 13% increase of seedling height comparing to that of chemical (for cv. TK8) or water (cv. TK9) treated control 2 weeks after seeding. The potential of WG6-14 in the control of seedling blight caused by Sclerotium rolfsii, was also investigated. By dual culture assay, WG6-14 was shown strongly antagonistic against S. rolfsii NTSR-01. The growth inhibition was due mainly to the membrane damage by WG6-14 produced antibiotics which was manifested by the greatly increased electrolyte leakage from the tested mycelia. A daily drenching of seedling trays with severe infection of Sclerotium rolfsii by 50X diluted WG6-14 for week greatly reduced increases of infected area and the total numbers of sclerotia produced. In a closed Petri dish system, the application of WG6-14 together with urea was shown to be lethal to sclerotial population of S. rolfsii NTSR-01 present in a non-sterile soil sample. The application of urea (0.5%) by itself led to only 56.8% reduction of the viable sclerotia, while with the combined use of WG6-14, the viable count was reduced to nearly zero. Although further effort are needed to work out the possibly involved mechanism regarding to the sclerotia killing, the results herein provided indicated clearly the great value of WG6-14 as a microbial agent for rice seedling production and as well the seeding blight control.

並列關鍵字

Bacillus subtilis WG6-14 ； biofungicide ； biocontrol ； electrolyte leakage ； Sclerotium rolfsii seeding blight of rice