水稻根际固氮菌促生特性评价

利用半固体培养基和土壤栽培经水稻特异性根际固氮菌处理的水稻幼苗,发现固氮菌属(Azotobacterspp.)菌株R-N00、R-N1110和R-N1112具有较强的促生能力。半固体培养基栽培获得接种3株菌株的水稻幼苗干重分别提高16.60%、9.23%和9.37%,根干重分别提高38.00%、30.00%和55.00%;土壤栽培获得接种菌株的水稻幼苗干重分别提高93.25%、90.18%和97.21%,根干重分别提高71.25%、72.21%和74.92%。这3株菌的固氮能力分别为13.37、11.93和13.57 mg.L-1;合成铁载体能力均达到5+;分泌吲哚乙酸分别为6.79、8.60和3.39 mg.L-1;溶磷能力分别为41.63、37.76和39.78 mg.L-1。结果表明,水稻根际促生菌的各种促生生理活性共同作用促进水稻幼苗生长,为高效生物肥料的研究提供参考。

Mechanisms of plant growth promotion of Azotobacter spp of rice PGPR on rice seedling

The rice seedlings inoculated with specific Azotobacter spp.of rice were cultured in semisolid medium and soil respectively,and the results displayed that the strains R-N00,R-N1110 and R-N1112 possess strong growth-promoting ability.Seedling dry weight increased by 16.60%,9.23% and 9.37%,and root dry weight increased 38.00%,30.00% and 55.00%,respectively,when cultivated in semisolid medium by the three strains.Seedling dry weight increased by 93.25%,90.18% and 97.21%,and root dry weight increased by 71.25%,72.21% and 74.92%,respectively,when cultivated in soil.The nitrogen fixation rates of the three strains were 13.37,11.93 and 13.57 mg?L-1 respectively;the ability of producing siderophore of the three strains were all 5+;the indole acetic acid(IAA) concentrations were 6.79,8.60 and 3.39 mg?L-1 respectively;the phosphate solubili-zation was 41.63,37.76 and 39.78 mg?L-1 respectively.The results show that growth-promoting physical activities of rice PGPR(plant growth-promoting rhizobacteria) promote the growth of rice seedlings together,and provide reference for the study of efficient bio-fertilizers.