转Bt基因玉米根际微生物和细菌生理群多样性

Quantity of culturable microorganisms and diversity of bacterial physiological groups in transgenic Bt corn rhizosphere

大田栽培条件下,以转Bt玉米Mon810及其亲本非转基因玉米为研究对象,在玉米的不同生育期测定根际土壤微生物的数量变化,并对细菌群落结构及多样性进行了分析。结果表明,各生育期内Bt玉米与对照相比根际土壤真菌无显著差异,但细菌在抽丝期,放线菌在苗期二者有显著差异。同种细菌功能群的数量变化在Bt玉米和对照各生育期内趋势一致,不同的菌群表现不同。亚硝化细菌、好气固氮菌、氨化细菌和钾细菌的数量变化波动较大,其中Bt玉米和对照相比好气固氮菌的数量在生育期内有5个生育期有显著差异,而氨化细菌、钾细菌和亚硝酸菌仅分别在乳熟期、喇叭口期及拔节期和抽雄期差异显著。好气纤维分解菌和硝化细菌在苗期、拔节期和喇叭口期差异显著,无机磷分解菌在乳熟期和完熟期数量差异显著。整个生育期内3种群落特征参数均保持基本稳定,除乳熟期和完熟期外Bt玉米根际微生物群落特征参数均高于对照。

The transgenic Bt corn Mon810 and its parental non-transgenic corn（the control）were grown in field to study the quantitative changes of culturable microorganisms and the diversity of bacterial functional groups in their rhizosphere at different growth stages.There was no significant difference in the colony-forming of cultivable fungi in the rhizosphere of Bt corn and the control across the whole growth period,but significant differences were detected for bacteria at silking stage and actinomycetes at seeding stage.The diversity of the same bacterial functional groups in the rhizosphere of Bt corn and the control was similar,but the diversity of different bacterial functional groups varied.The number of aerobic nitrogen-fixing bacteria in the rhizosphere of Bt corn was significantly different from that of the control at five growth stages of the whole growth period,while the numbers of ammonifying bacteria,potassium-solubilizing bacteria,and nitrosation bacteria were only significantly different at milking stage,trumpet stage and jointing stage,and tasselling stage,respectively.The numbers of aerobic cellulose-decomposing bacteria and nitrobacteria were significantly different at seedling stage,jointing stage,and trumpet stage,and that of phosphorus-decomposing bacteria was significantly different at milking stage and full-ripe stage.Across the whole growth period except at silking stage and full-ripe stage,the population characteristic parameters of the microorganisms in Bt corn rhizosphere were higher than those in non-Bt corn rhizosphere.