小麦根际固氮菌、解磷菌及解钾菌的互作效应

Effects of interaction between azotobacteria,P-releasing and K-releasing bacteria of wheat rhizosphere

固氮菌N2106、解磷菌P1616、解钾菌K0405是从小麦根际分离的分别具有高效固氮、溶磷、解钾功能的细菌,N2106-L、KL0405是发光酶基因LuxAB标记N2106及K0405所获得的标记菌株。将以上5种菌株分别单独培养并测定各菌悬液的细胞密度,然后将各菌株以相等的细菌数目进行混合液体培养。共设置4个不同的组合:N2106-L+P1616、N2106-L+K0405、KL0405+P1616以及N2106-L+KL0405+P1616,研究这些菌株之间的相互作用。结果表明,标记菌株的细胞密度均低于原始菌株1个数量级;两种菌株混合培养时,P1616促进了N2106-L和KL0405的生长,N2106-L和K0405之间存在某种相互作用;3种菌株混合培养时P1616为混合培养液中的优势菌种。

Azotobacteria N2106, P - releasing bacteria P1616 and K - releasing bacteria K0405 with the functions of N - fixing, P- releasing and K- releasing respectively were isolated from wheat rhizosphere. N2106 - L and KL0405 were gained by fluores- cence enzyme gene Lux AB transferred into N2106 and K0405. The above five strains were cultured and counted the cell density independently. Then every swain were mixed cultured in equal number in liquid. To study the interactions of these strains, three different combinations were set up： N2106 - L ＋ P1616, N2106 - L ＋ K0405, KL0405 ＋ P1616 and N2106 - L ＋ KL0405 ＋ P1616. it indicated that the cell densities of the labelled strains were lower than that of the original strains by 1 magnitude; When two strains mixed cultured, P1616 promoted the growth of N2106 - L and KL0405 and interaction exist between N2106 - L and K0405; When three strains mixed cultured, P1616 was dominant bacteria in liquid culture.