The Identification Of Pathogen And The Screeing And Application Of Bio-control Bacterial Strains On The Bacterial Wilt Of Curcuma Wenyujin

Bacterial wilt of Curcuma wenyujin(BWCW)caused by Ralstonia solanaceraum was becaming a threat for Curcuma wenyujin production and quality.In this study,A bio-organic fertilizer(BOF)fortified with beneficial microorganisms such as Bacillus amyloliquefaciens ZJU-C612-4 and Paenibacillus jamilae ZJU-C612-3.A serial of experiments were conducted to test their control efficacies of BWCW under greenhouse and field conditions.The possible control mechanisms of BOF were also discussed.The main results obtained were listed as follows:1.Four pathogenic strains(TSC7,TSC8,TSC9,and TSC10)were isolated from the diseaseed tuber of Curcuma wenyujin using selective medium M-SMSA.Based on the results of the morphological characteristics,16 Sr RNA sequence,flic gene sequence,egl gene phylogenetic analysis,the four fluidal strains were identified as phylotype I.Based on the utilization of of three hexyl alcohols and three disaccharides,R.solanaceraum TSC7,TSC8 and TSC9 were identified as biovar 4,R.solanaceraum TSC10 was identified biovar 3.2.Eight of thirty-seven strains stored in the laboratory,expecially strain ZJU-C612-3 and ZJU-C612-4 showed best in suppression of R.solanaceraum TSC7 in plateand the inhibitory zone of strains ZJU-C612-3 and ZJU-C612-4 were19.3 mm and 21.7 mm,respectively.Based on the results of 16 Sr RNA sequence and physiological and biochemical tests,strain ZJU-C612-3 was identified as Paenibacillus jamilae.It showed the protease,cellulase activity,and can produce siderophores,abundant fusaricidins and polymyxin.The antifungal index of ZJU-C612-3 against N.parvum?P.capsisi?B.dothidea?F.graminearum?R.solani?A.tenuissima 65.88%?63.24%?60.59%?50.00%?45.12%?37.35%,respectively.Bacillus amylobacillus ZJUC612-4 has a strong protease activity,and can produce a variety of bacillomycin,surfactin and fengycin.The antifungal index of ZJU-C612-4 against N.parvum?B.dothidea?P.capsisi?F.graminearum?R.solani?A.tenuissima 72.06%?67.94%?65.29%?55.60%?54.97%?52.41%,respectively.3.The BOF,a organic fertilizer fortified with ZJU-C612-3 and ZJU-C612-4 was tested on suppression of BWCW under both in greenhouse and in field.The results showed that applying BOF of 500 kg/mu could significantly reduce the incidence of bacterial wilt in greenhouse,and the control effect was 45.4%.In field.the control effect of 200 kg/mu BOF could reach more than 70% compared with that of compound fertilizer or sheep manure.