硅酸盐细菌NBT菌株在小麦根际定殖的初步研究

对硅酸盐细菌NBT菌株进行了耐药性标记，得到稳定的链霉素抗性标记菌NBT菌株，采用选择性培养基分离计数，通过琼脂平板和盆栽试验，研究了标记菌NBT在小麦根际的定殖动态及影响因素。结果表明，在灭菌土盆栽中，播种后9d左右NBT菌株在小麦根际的定殖水平达最高(1．4×10^8cfu·g^-1根土)，播种后54d左右趋向稳定，NBT菌株细胞数量为2．4×10^3cfu·g^-1根土；未灭菌土盆栽中，播种后9d左右NBT菌株的定殖水平达最高(3．8×10^8cfu·g^-1根土)，60d左右趋向稳定，菌数为3．1×10^3cfu·g^-1根土，牛物和非牛物因素对NBT菌株定殖小麦根系有影响。

Colonization of silicate bacterium strain NBT in wheat roots

The strain NBT of silicate bacterium was labelled with streptomycin, and a stable streptomycin resistance strain NBT was obtained. Its colonization dynamics and affecting factors in wheat rhizosphere were studied in agar plates and greenhouse pots were studied by counting the method with selective medium. The results of pot culture experiment showed that strain NBT could successfully colonize in the rhizosphere of wheat. In pot cultures of sterile soil, the highest colonization level (3.4 x 10(7) cfu.g-1 root soil) was reached on 9th day after seeds sown; at 54th day, the population of strain NBT tended to stable, and decreased to 1.4 x 10(4) cfu.g-1 root soil. In pot cultures of unsterile soil, the highest colonization level (3.8 x 10(7) cfu.g-1 root soil) was reached at 9th day, and the population of strain NBT tended to a stationary state at 60th day, with the numbers being 1.4 x 10(4) cfu.g-1 root soil. Some biological and abiotic factors could greatly influence the colonization of the beneficial microorganism.