青海解磷菌菌株的分离筛选

以青海省主要农耕区海东区和海南区的小麦、洋芋、油菜、蚕豆、辣椒、葱等16种作物的根际土壤为试验材料，通过解磷圈试验对土壤样品进行解磷菌的初筛和复筛。结果表明：共得到具有明显解磷圈的解磷菌28株。通过对解磷圈大小测定，筛选出y8-4、y5．1和w4．1等9株菌表现较好，解磷圈直径（D）与菌落直径（d）比值（D／d）均≥1．5。通过摇瓶复筛得出，y8-4解磷能力较强，菌液中磷含量达95μg／mL，其次是菌株y16-4和y9-4；其中菌株y9-4培养液的pH值有所降低。综合评价认为菌株y9-4的彤d较大，培养液中磷含量较高，且pH值有所降低，最后确定其作为适合青海农作区推广的高效解磷菌。

Isolation and Screening of Phosphorus Solubilizing Bacterial Strains in Qinghai Province

The phosphorus-solubilizing bacteria were isolated and screened from the rhizosphere soil of 16 crops in Qinghai Province.The results showed that 28 strains were obtained which had obviously dissolved phosphorus ring.By determining the ring size,9 strains were screened with the ratio of dissolving phosphate zone diameter to bacterial colony diameter(D/d) greater than or equal to 1.5.The phosphate-dissolving ability of strain y8-4 was higher,than y6-4 and y9-4.pH value of y9-4 culture solution decreased.Based on the comprehensive evaluation,strain y9-4 with higher D/d value,higher phosphorus content in the culture medium and decreased pH,which was suitable for popularizing in agricultural district in Qinghai.