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Abstract：
Fusarium crown rot (FCR) caused by Fusarium pseudograminearum is one of the most serious soil-borne diseases of wheat. Among 58 bacterial isolates from the rhizosphere soil of winter wheat seedlings, strain YB-1631 was found to have the highest in vitro antagonism to F. pseudograminearum growth. LB cell-free culture filtrates inhibited mycelial growth and conidia germination of F. pseudograminearum by 84.14% and 92.23%, respectively. The culture filtrate caused distortion and disruption of the cells. Using a face-to-face plate assay, volatile substances produced by YB-1631 inhibited F. pseudograminearum growth by 68.16%. In the greenhouse, YB-1631 reduced the incidence of FCR on wheat seedlings by 84.02% and increased root and shoot fresh weights by 20.94% and 9.63%, respectively. YB-1631 was identified as Bacillus siamensis based on the gyrB sequence and average nucleotide identity of the complete genome. The complete genome was 4,090,312 bp with 4357 genes and 45.92% GC content. In the genome, genes were identified for root colonization, including those for chemotaxis and biofilm production, genes for plant growth promotion, including those for phytohormones and nutrient assimilation, and genes for biocontrol activity, including those for siderophores, extracellular hydrolase, volatiles, nonribosomal peptides, polyketide antibiotics, and elicitors of induced systemic resistance. In vitro production of siderophore, β-1, 3-glucanase, amylase, protease, cellulase, phosphorus solubilization, and indole acetic acid were detected. Bacillus siamensis YB-1631 appears to have significant potential in promoting wheat growth and controlling wheat FCR caused by F. pseudograminearum.
摘要：
由假镰刀菌引起的镰刀菌冠腐病（FCR）是小麦最严重的土传病害之一。在冬小麦幼苗根际土壤中的58种细菌中，发现菌株YB-1631对假赤霉病的生长具有最高的体外拮抗作用。LB无细胞培养滤液抑制假赤霉病菌菌丝生长和分生孢子萌发达84.14%和92.23%，分别。培养滤液引起细胞的变形和破坏。使用面对面板测定法，YB-1631产生的挥发性物质抑制了假赤霉病的生长68.16％。在温室里,YB-1631使小麦幼苗FCR发生率降低84.02%,根和芽鲜重分别提高20.94%和9.63%,分别。基于gyrB序列和完整基因组的平均核苷酸同一性,将YB-1631鉴定为唾液酸芽孢杆菌。完整基因组为4,090,312bp，基因4357个，GC含量为45.92%。在基因组中，确定了根定植的基因，包括那些用于趋化性和生物膜生产的，促进植物生长的基因，包括植物激素和营养同化，和生物控制活性的基因，包括铁载体,细胞外水解酶，挥发物,非核糖体肽，聚酮类抗生素,和诱导系统抵抗的激发子。铁载体的体外生产，β-1,3-葡聚糖酶,淀粉酶，蛋白酶，纤维素酶,磷溶解，并检测到吲哚乙酸。唾液酸芽孢杆菌YB-1631似乎在促进小麦生长和控制由假赤霉病引起的小麦FCR方面具有显着的潜力。
