高寒草地禾草内生细菌B-401的鉴定及生物防治潜力评价

摘要

To study the biological control potential of B-401 endophytic bacteria in grasses on alpine grasslands, the determination of bacteriostatic ability was carried out by dual culture against plant pathogenic fungi.B-401 inhibited the growth of Phomafoveata,Stysanus stemonitis,Colletotrichum coccodes,Fusarium avenaceum, Fusariumoxysporum,Alternaria solani,Bipolaris sorokiniana and Fusarium solani by 74.45%,71.57%, 70.05%,48.01%,56.01%,60.25%,64.65% and 45.01% respectively.The control efficacy of B-401 against potato gangrene was 52.67% when a 10 times dilution of fermentation broth was sprayed on potato tubers dur-ing the storage-period.The concentration of IAA secreted by B-401 in King’s medium containing 100 mg/L tryptophan was 3.42 mg/L,and the concentration in the medium without tryptophan was 2.60 mg/L.B-401 possessed the capacity for nitrogen fixation but it did not have the capacity for phosphate solubilization.Based on morphology and physiological and biochemical characters,combined with 16S rDNA gene sequence analysis, B-401 was indentified as Bacillus atrophaeus.%为了明确高寒草地禾草内生细菌B-401的生物防治潜力，采用平板对峙法测定了其抑菌能力。抑菌谱表明， B-401对马铃薯坏疽病菌、马铃薯褐腐病菌、马铃薯炭疽病菌、马铃薯枯萎病菌、马铃薯干腐病菌、番茄早疫病菌、小麦根腐病菌、孜然根腐病菌和黄瓜枯萎病菌的抑制率分别达74．45％，71．57％，70．05％，48．01％，56．01％，60．25％，64．65％，45．01％和31．79％。在贮藏库中进行10倍液喷雾，对马铃薯坏疽病的防效达52．67％。生物学功能测定表明，该菌株在含有色氨酸和不含色氨酸的 King培养基中分泌 IAA分别为3．42和2．60 mg/L，且具有固氮能力，无溶磷能力。对B-401通过形态特征和生理生化测定，结合16S rDNA序列同源性分析，鉴定其为萎缩芽孢杆菌（Bacillusatrophaeus）。