荒漠植物根际解磷细菌的筛选及抑菌和促生特性研究

Screening of Phosphate-solubilizing Bacteria in Rhizosphere of Desert Plants and Their Antibacterial and Growth-promoting Effects

从荒漠植物根际筛选解磷菌株并研究其促生效应,为推动荒漠区微生物资源的开发和利用提供有效的参考。采用平板培养和钼锑抗比色法筛选荒漠植物根际土壤中具有解磷活性的细菌菌株,测定其促生和抑菌活性,并利用盆栽接种试验分析代表菌株对柠条幼苗生长的促进作用。结果表明:筛选出6株溶解无机磷的菌株,溶磷量为52.82~63.93 mg/L,其中菌株IP6的溶磷量最高;筛选出4株溶解有机磷的菌株,溶磷量为2.33~2.80 mg/L;多数解磷菌同时具备固氮、产IAA和分泌铁载体能力,所有菌株对玉米大斑病菌和马铃薯干腐病菌都能产生明显的抑制作用。与不接菌对照相比,接种沙雷氏菌IP6使柠条幼苗的株高、根长和鲜质量显著提高12.39%、9.85%和30.68%;接种假单胞菌OP2使柠条幼苗的株高、根长和叶片数显著提高13.29%、8.62%和19.56%,鲜质量和干质量显著增加46.32%和37.98%,二者促生效果显著,具有进一步开发为微生物肥料的潜能。

Screening phosphate-solubilizing bacteria from the rhizosphere of desert plants and studying their growth-promoting effects can lay a foundation for the development and utilization of microbial resources in desert areas.Plate culturing and molybdenum-antimony colorimetry methods were used to select phosphate-solubilizing bacterial strains from the rhizosphere soil of desert plants,and their growth-promotion and antibacterial activities were determined,followed by a pot inoculation test to analyze the growth-promoting effects of representative strains on Caragana sp.seedlings.The results showed that six strains capable of dissolving inorganic phosphate were screened,with phosphate-solubilizing capacities ranging from 52.82 to 63.93 mg/L,among which strain IP6 had the highest phosphate solubility.Four strains capable of dissolving organic phosphate were screened,with solubilization capacities ranging from 2.33 to 2.80 mg/L.Most phosphate-solubilizing bacteria also possessed the abilities to fix nitrogen,produce indole-3-acetic acid(IAA),and secrete siderophores.All strains could produce obvious inhibitory effects on the pathogens of Exserohilum turcica and Fusarium solani.Compared with the control,inoculation with Serratia sp.IP6 significantly increased the plant height,root length and fresh weight of Caragana sp.seedlings by 12.39%,9.85%and 30.68%,respectively;and inoculation with Pseudomonas sp.OP2 significantly increased the plant height,root length and number of leaves by 13.29%,8.62%and 19.56%,respectively,and the fresh weight and dry weight by 46.32%and 37.98%,respectively.The growth-promoting effects of both strains were significant,indicating their potential to be further developed as microbial fertilizers.