根际耐盐真菌分离筛选及溶磷促生性能分析

Isolation,Screening,Phosphorus Solubilization and Plant Growth-Promoting Characteristics of Rhizosphere Halotolerant Fungi

溶磷微生物可提高土壤中有效磷含量,但目前筛选的溶磷菌株在盐渍化土壤中应用的潜力有限。以滨海盐生植物根际土壤为材料,分离筛选可用于盐碱土改良的高效耐盐解磷菌株,为盐碱土生物菌肥的研制提供优质菌种资源。结果表明,北戴河湿地及曹妃甸湿地的3种原生盐地植物根际土壤中共分离筛选无机磷降解菌株5株和有机磷降解菌株3株,命名为C1-C7和G1,均能耐受10%的盐浓度。菌株间解磷能力差异显著,D/d为1.05~1.81,无机磷降解菌解磷量为26.61~4415.00mg/L,与对照相比有效磷增量为0.80~4371.10mg/L;有机磷降解菌解磷量为1.96~5.79mg/L,有效磷增量-3.40~0.20mg/L,有效磷含量与D/d之间相关性不强。其中菌株C1降解无机磷能力最强,溶磷量达4397.70mg/L,吲哚乙酸(IAA)分泌量为33.07mg/L,经分子鉴定该菌株为草酸青霉,是一株高效耐盐解磷菌,兼具促生作用,可以考虑作为盐碱地改良菌肥的重点菌种,与植物协同改良修复中重度盐碱土,可有效提高盐碱地土壤肥力,有更好的应用潜力。

To obtain high-efficiency halotolerant phosphorus strains and provide high-quality bacteria fertilizer species resources for the development of saline soil,phosphate solubilizing fungus were isolated and screened from the rhizosphere soil of coastal halophytes.The results showed that five inorganic phosphorus strains and three organic phosphate solubilizing strains were isolated in rhizosphere soil of three halophytes from Beidaihe wetland and Caofeidian wetland,named C1-C7,G1,grown at 10%sodium chloride medium.The D/d values of the eight fungus ranged from 1.05 to 1.81.The effective phosphorus content was 26.61-4415.00 mg/L in the inorganic phosphorus strains,which was 0.80-4371.10 mg/L higher than CK;the effective phosphorus content was 1.96-5.79 mg/L in organic phosphate solubilizing strains,which was-3.40-0.20 mg/L higher than CK.There was a weak correlation between effective phosphorus content and D/d.The strain C1 could produce 4397.70 mg/L available phosphate,meanwhile,C1 had the ability to promote plant growth with IAA secretion of 33.07 mg/L.The strain C1 was identified as Penicillium oxalicum,and the effective phosphorus content between strains showed significant difference.Strain C1 was a highly effective phosphate-dissolving halotolerant fungi with growth-promoting activity.It could be considered as a key strain for the development of microbial fertilizer in saline-alkali land which had great potential to improve phosphorus utilization rate in moderate-to-severe saline soil by plant-microorganism.