核桃专用溶磷、解钾、促生长高效功能微生物的筛选与复配

为解决土壤内磷、钾难以被核桃吸收利用的问题,采用涂布稀释的方法,筛选出4株溶磷、解钾、促生长功能性微生物,对其进行鉴定,研究其复配后对核桃苗的影响。从土壤中筛选出1326株微生物,去除形态相同、革兰氏染色结果相同的菌株剩余536株菌,检测其溶磷、解钾、分泌激素的能力,筛选出4株功能菌株,编号为ht1、ht2、ht3、ht4;对4株菌进行形态特征观察及生理生化鉴定,结合16S rDNA序列进行分析,确定ht1、ht4为解淀粉芽孢杆菌(Bacillus amyloliquefaciens),ht2、ht3为枯草芽孢杆菌(Bacillus subtilis);对4株功能菌进行平板对峙试验,发现4株菌株无抑制作用,经过不同菌种复配后,检测出4株功能菌株复配的IAA分泌量有很大幅度的提高。探索4株菌种不同比例的复配效果,检测出4株菌种在土壤中具有较强定殖能力,测量核桃苗农艺性状,发现4株菌剂以1:1:1:1的比例混合效果最好,树高、枝下高、冠幅等指标明显高于其他处理。

Special High-efficient Microorganisms for Dissolving Phosphorus,Potassium and Growth-promoting of Walnut: Screening and Compounding

To solve the problem that phosphorus and potassium in soil are difficult to be absorbed and utilized by plants, the functional microorganisms for dissolving phosphorus, potassium and growth promotion were screened out by the method of coating dilution. The results showed that 1326 strains of microorganisms were screened out from soil, 536 strains remained by removing the strains with the same morphology and gram staining results. The ability to dissolve phosphorus and potassium and secrete hormones was detected, and 4 functional strains were identified to study the effects of their combinations on walnut seedlings. Through the observation of the morphological characteristics and the physiological and biochemical identification of the 4 strains, and with the combination of 16S rDNA sequence analysis, ht1 and ht4 were confirmed as Bacillus amyloliquefaciens and ht2 and ht3 as Bacillus subtilis. Plate confrontation test was carried out on the 4 functional strains, and it was found that the 4 strains had no inhibitory effect. After the combination of different strains, the IAA secretion of the 4 functional strains was significantly increased. The compounding effect of the 4 strains with different proportions was explored, and the strong colonization ability of the strains was detected in the soil. The measurement of agronomic traits of walnut seedlings showed that the compounding effect of the 4 strains with 1:1:1:1 ratio was the best, and the indexes of tree height, sub-branch height and crown width were significantly higher than those of other treatments.