紫花苜蓿根际氢氧化细菌对小麦的促生作用与促生机制

从紫花苜蓿根际土壤分离出8株氢氧化细菌, 测定其对小麦生长的促进作用, 通过小型栽培实验对萌发的小麦进行表征, 并利用ACC脱氨酶法和铁载体检测实验对促生机制进行了初步研究. 结果表明, 菌株WMQ-7, FMG-3, FMG-5对小麦的促生作用显著, 根长和苗长均比对照增加50%和30%以上; 小麦种子的根上部分干重平均值比对照分别增加95.24%, 57.14%, 47.62%; 成熟的小麦麦粒数均比对照多1倍以上. 菌株WMQ-7既为ACC脱氨酶阳性又为铁载体阳性, ACC脱氨酶活力为0.671 U/μg, 铁载体在404 nm处有明显的吸收峰, 吸光值为0.834, 经检测其产生的铁载体的量为7.1996 µg/mL并确定该铁载体类型不是儿茶酚型. 因此推测, 菌株WMQ-7对小麦的促生作用机制可能与ACC脱氨酶活性和铁载体阳性有关.

Plant growth promoting and its mechanism of hydrogen-oxidizing bacteria isolated from Medicago sativa rhizosphere

Eight hydrogen-oxidizing bacteria isolated from Medicago sativa rhizosphere were test on wheat growth promoting effect. Superficial characteristics of germinal wheat were test by small scale cultivated experiments. ACC deaminase and siderophore were test to find the plant growth promoting mechanisms of hydrogen-oxidizing bacteria. Results show that WMQ-7, FMG-3 and FMG-5 have strong ability to promote the growth of wheat. The length of roots and sprouts respectively increased over 50% and 30% than blank control. Dry biomass of wheat effect by the strains was respectively increased 95.24%, 57.14% and 47.62%. Quantity of grain increased over 100%. Strain WMQ-7 can produce both of ACC deaminase and siderophore. ACC deaminase activity is 0.671 U/μg. Siderophore concentration is 7.1996 μg/mL and absorption peak is at 404 nm and the absorbance was 0.834. So we speculate that ACC deaminase activity and siderophore would be the plant growth promoting mechanisms of strain WMQ-7.