一株烤烟根际解钾细菌的鉴定及其在烤烟生产中的应用

Identification of a silicate bacterium from flue-cured tobacco rhizosphere and application in flue-cured tobacco production

对分离自烤烟根际的解钾菌K03进行分类鉴定,并通过小区试验探讨其在烤烟生产中的应用。通过形态和生理生化特征及16S rDNA序列分析,将K03菌株鉴定为阿氏肠杆菌(Enterobacter asburiae)。将该菌制作菌肥,烤烟移栽时施入30 kg.hm-2菌肥,同时减施20%的K肥,与全量施用K肥相比,可显著提高不同生长期烤烟根际细菌数量和解钾菌的数量。降低放线菌的数量和现蕾期真菌的数量,烤烟根际微生物区系以细菌和解钾菌为优势菌群。圆顶期烤烟根际土壤中矿质元素除Mg的有效性有所降低外,P,K,Ca,Cu,Zn,Fe和Mn的有效性有不同程度的提高,K的有效性提高27.08%,烤烟产量和产值分别提高7.38%和5.47%。施用解钾菌肥可有效减少化肥的使用量,是可持续生产优质、无公害烟叶的有效途径。

A silicate bacterium K03 isolated from flue-cured tobacco rhizosphere was identified by morphologic characteristic,physiological and biochemical reaction,and phylogenetic tree based on 16S rDNA sequences.The results showed that this silicate bacterium belong to Enterobacter,may be Enterobacter asburiae.Silicate bacterium fertilizer preparaed using K03 was applied at a rate of 30 kg·hm-2 with minus 20% K dosage of full fertilizer when flue-cured tobacco was transplanted in plots.The numbers of rhizobacteria and rhizo-silicate bacteria significantly increased during the whole growth period,while the number of rhizoactinomycetes during the whole growth period and the number of rhizofungi at budding stage significantly decreased,compared to the control which was treated by 100% K of the recommended doses for tobacco.It indicated that the dominant microbial flora in tobacco rhizosphere altered to bacteria and silicate bacteria.The availability of mineral elements P,K,Ca,Cu,Zn,Fe and Mn,except Mg,in tobacco rhizosphere in tobacco topping stage were higher than that of the control,especially the availability of K was 27.08% higher than the control.The yield and production value of tobacco leaves were 7.38% and 5.47% higher than the control.The results suggested that silicate bacteria fertilizer reduced application rates of chemical K fertilizers,which could be an efficient way to produce high-quality and pollution-free tobacco leaves sustainably.