古国槐叶片溶磷内生真菌的筛选及其促生潜力初探

Screening of Phosphate-Solubilizing Endophytic Fungi from Ancient Sophora japonica Leaves and Their Potential for Plant Growth-Promoting

该试验从周公庙古国槐叶片内分离、筛选具有溶磷能力的内生真菌,采用溶磷圈法和钼锑抗比色法测定其溶解无机磷的能力,同时测定其回接后对国槐无菌苗叶绿素、可溶性蛋白质、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性的影响,探究内生真菌的溶磷能力及其促生效应。结果表明:(1)从古国槐叶片中分离出的55株内生真菌中,28株具有溶磷能力,其中溶磷能力较强的活性菌株有12株:ZG-7为拟盘多毛孢(Pestalotiopsis sp.),ZG-9、ZG-23、ZG-32、ZG-36和ZG-53为镰刀菌(Fusariumsp.),ZG-15和ZG-34为曲霉(Aspergillus sp.),ZG-39和ZG-51为链格孢(Alternariasp.),ZG-42为木霉(Trichoderma sp.),ZG-48为附球菌(Epicoccumsp.)。(2)曲霉属真菌ZG-15和ZG-34的溶磷圈直径(d)及其与菌落直径(D)的比值d/D均高于其他菌株,对Ca_3(PO_4)_2的溶解能力最强(1 238.28和941.22mg·L-1),并极显著高于其他菌株(P<0.01)。(3)4株内生真菌ZG-7、ZG-9、ZG-15和ZG-48回接至国槐无菌苗10d后,可从苗根组织的皮层细胞中观察到内生菌丝,其中黑曲霉(Aspergillus niger)ZG-15可显著提高国槐无菌苗的叶绿素含量、可溶性蛋白质含量、SOD、POD活性(P<0.05),从而维持幼苗的正常生长和提高其抗逆能力,为该试验得到的促生潜力优势内生真菌,可为古国槐的有效保护及林木溶磷生物菌肥的生产提供依据。

To explore the phosphate-solubilizing ability of endophytic fungi and their plant growth-promo-ting potential ,we evaluated the phosphate-solubilizing capability of endophytic fungi from ancient Sophora j aponica leaves in Zhougongmiao by the method of dissolved phosphorus cycle and molybdenum-bule ,and detected the effects of inoculated sterile host plantlet on chlorophyll ,soluble protein contents ,SOD and POD activities .The results showed that ,there were 28 out of 55 fungi strains from ancient S .japonica leaves with phosphate-solubilizing capability ,and twelve strains among twenty-eight endophytic fungi dis-played strong capability of dissolving phosphate of Ca3 （PO4 ）2 by a test of phosphate-solubilizing＆amp;nbsp;capability ,they were Pestalotiopsis sp .（ZG-7） ,Fusarium sp .（ZG-9 ,ZG-23 ,ZG-32 ,ZG-36 and ZG-53） , Aspergillus sp .（ZG-15 and ZG-34） ,Alternaria sp .（ZG-39 and ZG-51） ,Trichoderma sp .（ZG-42） and Epicoccum sp .（ZG-48） .Two strains with strong phosphate-solubilizing capability were then picked up , ZG-15 and ZG-34 ,belonged to Aspergillus spp ..Their diameter of phosphorus solubilizing circle （d） and d/D （D ,colony diameter） were both higher than that of others ,and their solubilization of Ca3 （PO4 ）2 accounted for 1 238 .28 mg？L -1 and 941 .22 mg？L -1 ,respectively ,which were significantly higher than that of others and control （P〈0 .01） .Four strains （ZG-7 ,ZG-9 ,ZG-15 and ZG-48） from different genera were inoculated into aseptic S . j aponica seedlings bottle to ensure their contact upon with each other . Mycelium was observed infecting into the cortex cells and around the surface epidemical cells of root tissue ;underthetreatmentby AspergillusnigerZG-15,S.japonicaseedlings＇chorophyllcontent,solu-ble protein content ,SOD and POD net activities were all obviously higher than that of control （P〈0 .05） , so ,ZG-15 could maintain healthy seedling grow th and improve seedling resilience ,which showed a great potential for ancient S .j aponica protection and a potential application as an organism-fertilizer for forest tree .