糜子溶磷内生真菌的筛选及其鉴定

Screening and identification of phosphorus-soluble fungi in Panicum miliaceum

[目的]从产自宁夏回族自治区、甘肃省的不同糜子品种中分离、筛选出具有高效溶磷能力的内生真菌菌株并在糜子中接种,旨在评价其溶磷促生效果。[方法]采用溶磷圈和钼锑抗比色法测定糜子溶磷能力,同时通过盆栽试验测定其对糜子苗期生长、光合及磷素吸收累积的作用。[结果]从糜子种子内分离的内生菌株中有5株具有溶磷能力。其中,2株为来自甘肃省的LM1(Talaromyces sp.黄丝曲霉属),LM2(Talaromyces sp.),3株为来自宁夏回族自治区GM1(Talaromyces sp.),GM2(Penicillium sp.青霉属),GM3(Penicillium chrysogenum产黄青霉)。GM1,GM3号菌株溶磷圈直径(D)与菌落直径(d)的比值(D/d)较大,分别达到了1.59,1.47;相同成分液体培养基中可溶性磷含量分别为264.75和323.48μg/ml,溶磷率分别达到5.26%和6.43%,显著(p<0.05)高于其他菌株;其pH值分别为2.88和3.63,显著(p<0.05)低于其他菌株。5个溶磷真菌的溶磷率与pH值呈极显著(p<0.01)负相关。盆栽试验中,当磷用量减少75%和50%并接种溶磷菌GM3时,糜子SPAD值(叶绿素相对含量的一个参数)分别为20.63和21.46,净光合速率分别达为23.2和25.87μmol/(m2·s)。植株全磷含量分别为10.08和12.39 mg/盆,均显著高于对照(CK)(p<0.05),表明接种GM3对糜子促生作用表现明显。[结论] GM3为本试验得到的目标菌株,并且表现出良好的溶磷促生作用。

[Objective]The endophytic strains with the ability of phosphorus-soluble were isolated and screened from the seeds of different Panicum miliaceum varieties from Ningxia Hui Autonomous Region and Gansu Province,and inoculated in Panicum miliaceum to evaluate the effects of phosphorus dissolution and growth promotion.[Methods]The phosphorous dissolving capacity was determined by phosphorous ring and molybdenum-antimony colorimetric method,at the same time,pot experiments were conducted to determine its effects on seedling growth,photosynthesis and phosphorus absorption.[Results]Among the endophytic fungal strains isolated from Panicum miliaceum seeds,five strains had the ability to dissolve phosphorus,two strains were from Gansu Province〔LM 1(Talaromyces sp.),LM 2(Talaromyces sp.)〕and 3 strains were from Ningxia〔GM 1(Talaromyces sp.),GM 2(Penicillium sp.),GM 3(Penicillium chrysogenum)〕.The ratio of the diameter of solubilizing phosphorus circle(D)to the diameter of colony(d)of strain GM 1 and GM 3 was the largest,reaching 1.59 and 1.47;The content of soluble phosphorus in the liquid medium of the same composition was 264.75μg/ml and 323.48μg/ml,respectively,and the phosphorus dissolution rate reatched 5.26%and 6.43%,respectively,which was significantly higher than other strains(p<0.05);the pH value was 2.88 and 3.63,respectively,which was significantly lower than other strains(p<0.05);The phosphorus dissolution rate of the 5 fungis was negatively correlated with the pH value(p<0.01).In the pot experiment,when the phosphorus consumption was reduced by 75%and 50%,and inoculated with phosphorus-soluble fungi GM 3,the SPAD value(a parameter of chlorophyll relative content)of Panicum miliaceum was 20.63 and 21.46,respectively,net photosynthetic rate reached 23.2 and 25.87μmol/(m 2·s),the total phosphorus content of the plant was 10.09 and 12.39 mg/pot,respectively,which were significantly higher than the control(CK)(p<0.05).[Conclusion]Inoculation of GM 3 had obvious pro-growth effect on Panicum miliaceum.GM 3 was the target strain obtained in this experiment,and it showed a good effect of promoting the growth and dissolved phosphorus.