兼具解磷解钾功能生防菌分离鉴定及效果评价

Isolation,Identification and Effect Evaluation of Bio-control Bacteria with Phosphorus and Potassium Dissolving Function

利用稀释涂布法将采集到的不同土壤样品稀释涂布到NA培养基平板中进行培养,将分离到不同形态的菌株编号并接入解钾解磷培养基平板中筛选,然后将平板中产生溶解圈的菌株分离纯化;采用浅盘法将过滤消毒后的根结线虫放入加有不同菌株发酵液的贝式培养皿中,观察杀线效果,然后从中进一步筛选兼具解磷释钾作用的多功能生防菌株;利用钼锑抗比色法和火焰分光光度计分别测定菌株的解磷解钾效果,并进行形态学、生理生化及分子鉴定。结果表明,从解磷解钾培养平板中筛选出9株解磷释钾细菌。杀线虫试验结果显示,48 h后,其中3株杀线虫校正死亡率在50%以上。通过钼锑抗比色法测定筛选到的3种菌株的解有机磷结果为0.82~3.66 mg/L,解无机磷结果为40.90~61.80 mg/L。利用火焰分光光度计测得3种菌株分解无机钾的结果为6.72~8.74 mg/L。经形态学、生理生化和分子鉴定结果分析,其中2种菌株为芽孢杆菌,另外1种菌株为假单胞菌。

By dilution coating method,different soil sample dilutions were cultured in NA culture medium to isolate strains.Strains with different forms were cultured in phosphorus and potassium dissolving medium plate to screen and identify the strains with dissolving ring.To further screen the strains with bio-control function,the sterilized root knot nematodes by shallow dish method were added into the petri dish with fermentation of different strains to observe the nematicidal effect.The dissolving efficiencies of phosphorus and potassium of different strains were further tested through molybdenum antimony colorimetric method and flame spectrophotometer.The screened strains were identified through morphological,physiological and biochemical,and molecular identification measures.The results showed that nine strains of bacteria were screened from the phosphorus and potassium dissolving medium.The nematicidal effects showed that the corrected mortality rates of three strains were more than 50%after 48 h.The organic and inorganic phosphorus dissolving results of these strains were 0.82-3.66 mg/L and 40.90-61.80 mg/L,respectively.The inorganic potassium dissolving results of three strains of were 6.72-8.74 mg/L.After analysis of morphology,physiology,biochemistry and molecular identification,two of the strains were Bacillus and the other was Pseudomonas.