作 者：
刘鲁峰;狄义宁;何丽莲;谢林艳;胡一凡;李富生
关键词：
枯草芽孢杆菌;促生作用;IAA;光合指标;液质联用仪
摘 要：
【目的】内生枯草芽孢杆菌B9菌株是一株分离于甘蔗根部的内生枯草芽孢杆菌,探究其促生长作用及产吲哚乙酸(IAA)能力,为下一步将其研制成高效微生物肥料接种剂提供理论依据。【方法】以玉米种子、甘蔗单芽茎和甘蔗组培苗为供试材料,通过浸泡接种玉米种子与甘蔗单芽茎,明确B9的最适促生长密度,观察它们的生长势并测定芽长、根长、株高、生根数和根系重量;通过灌根接种甘蔗组培苗,观察试管组培苗中根系长势,测定盆栽组培苗根长、株高、根系活力、氮代谢相关酶活性、叶绿素以及光合指标,运用液质联用仪检测无菌上清液中与促生长相关的IAA的含量。【结果】B9菌液稀释后对玉米种子和幼苗均有一定的促生长作用,随着菌液稀释倍数的增加,促生长效果呈先增加后减弱的趋势,在1.0×10~6 CFU/mL时,对玉米生长情况的影响达到最佳。甘蔗单芽茎经1.0×10~6 CFU/mL的B9菌液处理后,其相关的形态和农艺性状均显著优于清水对照(P<0.05)。在该密度下,甘蔗组培苗的株高、根长、叶绿素含量、谷氨酰胺合成酶(GS)、谷氨酸合成酶(GOGAT)、叶片净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)和根系活力等指标均明显优于CK。在LB培养基B9菌液中,吲哚乙酸含量增加明显,在9 d时达到(95.63±2.33) ng/mL,比空白对照增加1054.9%。在Landy培养基菌液中,同样检测到吲哚乙酸呈不断增长的态势,在9 d时比对照高出2.56倍。【结论】B9菌株对甘蔗和玉米均具有明显的促生长效果,且发酵液中的IAA分泌能力强。
译 名：
Study on the Growth Promotion Effect and IAA Production Capacity of Bacillus subtilis B9
作 者：
LIU Lufeng;DI Yining;HE Lilian;XIE Linyan;HU Yifan;LI Fusheng;College of Agronomy and Biotechnology, Yunnan Agricultural University;Sugarcane Research Institute, Yunnan Agricultural University;
关键词：
Bacillus subtilis;;growth promoting effect;;indole-3-acetic(IAA);;photosynthetic indexes;;liquid mass coupling apparatus
摘 要：
[Purpose]B9 strain is an endophytic Bacillus subtilis isolated from the root of sugarcane. The study on its growth-promoting effect and indole-3-acetic acid(IAA) production capacity provides a theoretical basis for the development of high-efficiency microbial fertilizer inoculant.[Method]Corn seed, sugarcane single bud stem and sugarcane tissue culture seedlings were test materials, and corn seed and sugarcane single bud stem were inoculated by soaking, and the optimal growth concentration of B9 was explored. Their growth potential was observed and the bud length, root length, plant height, root number and root weight were measured. The roots of the sugarcane tissue culture seedlings were inoculated by root irrigation, and the root growth of the tissue culture seedlings was observed. The root length, plant height, root activity, nitrogen metabolism related enzyme activities, chlorophyll and photosynthetic indexes of the potted seedlings were measured. The use of liquid chromatography-mass spectrometry(LC-MS) to detected probiotic-related substances of content in indole-3-acetic acid(IAA).[Result]The dilution of B9 bacteria had a certain promoting effect on corn seeds and seedlings. The growth-promoting effect showed an increasing first and then decreasing trend with the increase of the dilution factor. At the concentration of 1.0×10~6 CFU/mL, the effect on corn growth is optimal. The related morphological and agronomic characters of sugarcane single bud stem were significantly better than those of clear water by treatment with 1.0×10~6 CFU/mL B9 bacterial solution(P<0.05). At this concentration, plant height, root length, chlorophyll content,glutamine synthetase(GS), glutamate synthase(GOGAT), net photosynthetic rate(P_n), stomatal conductance(G_s), transpiration rate(T_r), root activity of sugarcane tissue culture seedlings were significantly better than CK treatment. In the B9 bacterial solution of LB medium, the increase indole-3-acetic was significant, reaching(95.63±2.33) ng/mL at the 9 d and an increase of 1054.9% over the blank control. In the Landy medium, the indoleacetic acid was detected to be increasing trend, which was 2.56 times higher than the control at the 9 d.[Conclusion]In conclusion, B9 strain has obvious growth promotion effect on sugarcane and corn, and the secretion capacity of IAA in fermentation liquid is strong.
