青稞(Hordeum vulgare L. var. nudum)是西藏主要粮食作物,在青藏高原广泛种植,具重要经济与生态价值。但西藏地区的独特环境致麦类病害频发,化肥农药的过度使用严重威胁生态。本研究为探寻环境友好生物防治法,从青稞根际土筛选拮抗菌株,通过平板对峙法评估抑菌活性、研究发酵滤液特性及促生特性,以筛选优良菌株,为开发青稞专用微生物肥料提供支持。研究结果表明:从健康青稞根际土壤中分离获得5株对赤霉病菌(Fusarium graminearum)和根腐病菌(Fusarium solani)具有显著拮抗作用的菌株,经形态学观察和16S rRNA基因序列分析鉴定,菌株QK-1属于假单胞菌属(Pseudomonas sp.)、菌株QK-7和QK-32属于产碱杆菌属(Alcaligenes sp.)、菌株QK-17属于窄食单胞菌属(Stenotrophomonas sp.)、菌株QK-18属于芽孢杆菌属(Bacillus sp.);发酵滤液抑菌试验显示,菌株QK-7和QK-17对靶标病原菌具有显著抑制作用,其效果分别为76.66%和90.84%,且在60 ℃ ~ 80 ℃ 温度范围内保持稳定;综合抑菌活性和促生特性评估,QK-7菌株表现出最优异的生物防治潜力。本研究结果为开发适用于西藏地区麦类作物的生物防治制剂提供了重要的菌种资源和技术支撑。
Abstract
Barley (Hordeum vulgare L. var. nudum) is a major food crop in Xizang, widely cultivated on the Tibetan Plateau, with important economic and ecological values. However, the unique environment of Xizang has resulted in the frequent occurrence of wheat diseases, and the excessive use of chemical fertilizers and pesticides has seriously threatened the ecology. This study aimed to explore the environmentally friendly biological control method, from the barley inter-root soil screening antagonistic strains, study fermentation filtrate characteristics and the promotion of the characteristics of the screening of good strains, through the plate standoff method to assess the inhibitory activity, and provide support for the development of barley special microbial fertilizers.The results showed: Five strains with significant antagonistic effects against Fusariumgraminearum and Fusarium solani were isolated from healthy barley rhizosphere soil. Morphological observation and 16S rRNA gene sequencing identified them as Pseudomonas sp. QK-1, Alcaligenes sp. QK-7 and QK-32, Stenotrophomonas sp. QK-17, and Bacillus sp. QK-18; Fermentation filtrate tests revealed that strains QK-7 and QK-17 exhibited significant inhibitory effects on target pathogens with 76.66% and 90.84%, with stable activity within the temperature range of 60 °C ~ 80°C; Comprehensive evaluation of antimicrobial activity and growth-promoting traits indicated that strain QK-7 demonstrated the most promising biocontrol potential. These findings provide valuable microbial resources and technical support for developing biocontrol agents suitable for cereal crops in Xizang.
青稞(Hordeum vulgare L. var. nudum)属于禾本科大麦属,是大麦的一个变种,在全世界均有种植,在我国主要种植于西藏、青海、云南、甘肃、四川等省区海拔较高的地区,是最重要的粮食作物之一,因其具有成熟期短、耐寒性强、适应性广等特点,能够在海拔超过4 200 m的高寒地区种植[1]。并且青稞富含多种氨基酸、膳食纤维、维生素和人体所需要的微量元素,具有卓越的药用价值和丰富的营养价值,还可用于酿造青稞酒、制饴糖、用作饲料等。近年来,随着西藏经济的快速发展和人民生活水平的不断提高,对青稞的需求持续增长,然而,农作物病虫害如赤霉病[2]、根腐病等,已成为制约青稞产量的主要因素,严重威胁粮食安全。
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