油用牡丹根际解有机磷细菌的筛选及解磷功能研究

Organic Phosphate-solubilizing Bacteria Screening in the Rhizosphere of Paeonia ostii and Study on Their Phosphate-solubilizing Capabilities

油用牡丹作为市场上新兴的木本油料作物,土壤有效磷缺乏严重制约油用牡丹生长发育以及产量和品质的提升。分离筛选油用牡丹高效解磷细菌,充分发挥其根际微生物的作用,是实现油用牡丹高产优质目标、保障农业绿色发展的有效途径。以不同生长年限油用牡丹‘凤丹’根际土壤为研究对象,选用以植酸钙为磷源的培养基,利用平板稀释法分离筛选具有解有机磷能力的细菌,并利用16S rDNA测序技术对菌株进行鉴定,结合溶磷圈法和钼锑抗比色法分析其解磷能力。从一、三、四年生油用牡丹根际土壤中共筛选出14株解有机磷菌株。其中隶属于芽孢杆菌属和假单胞菌属的各有5株,隶属于节杆菌属的有3株,还有1株隶属于新鞘氨醇杆菌属;14株解有机磷菌株溶磷指数和溶磷效率分别在1.6-9.0以及60%-800%之间,其中一年生油用牡丹根际筛选到的菌株FD1-15的溶磷指数和溶磷效率均最高;培养液中速效磷含量为2.88-5.30 mg/L,活化率在26.44%-62.13%之间,解磷能力和活化能力最强的是从三年生油用牡丹根际筛选获得的菌株FD3-13,隶属于芽孢杆菌属。这为提高油用牡丹的产油量和食用品质提供理论和技术支撑,同时也为微生物菌肥的研发和应用提供一定的参考。

Paeonia ostii as a new woody oil crop with high oil values,the deficiency of available phosphorus in the soil severely restricts its growth and development,yield and quality.Isolation and screening of highly effective phosphate-solubilizing bacteria(PSB)and playing the role of rhizosphere microorganisms is an effective way to achieve the goal of high yield and high quality of P.ostii and ensure the green development of agriculture.Seedlings of P.ostii‘Fengdan’growing for different years were selected as study objects,and phytin was selected as the only phosphorus(P)source in the medium.Then the method of plate dilution was employed to isolate organic phosphate-solubilizing bacteria.And finally the 16S rDNA sequencing technology was used for molecular identification of these strains,and methods of phosphatesolubilizing circle and liquid culture were applied to analyze their phosphate-solubilizing abilities.As results,14 strains of PSB were isolated from the rhizosphere of P.ostii in 1 year,3 and 4 years.Among them,there were 5 strains of Pseudomonas,5 strains of Bacillus,3 strains of Arthrobacter and one strain of Novosphingobium,respectively.The phosphate-solubilizing index and phosphate-solubilizing efficiency of 14 strains ranged in 1.6 to 9.0 and 60%to 800%,among them the phosphate-solubilizing index and phosphate-solubilizing efficiency of strain FD1-15 was the highest.The available P content in liquid culture of PSB ranged in 2.88 mg/L to 5.30 mg/L,and the mobilization ratio ranged in 26.44%to 62.13%.The strain FD3-13 isolated from the rhizosphere of P.ostii with three-year-seedlings presented the strongest phosphatesolubilizing capacity,which belonged to genus of Bacillus.The results provide a theoretical and technical support for improving oil yield and edible quality of oil peony and useful reference for development and application microbial fertilizers.