鞘氨醇单胞菌菌株CL01的分离鉴定及其对连作西瓜的促生效应  

Isolation and Identification of Sphingomonas sp.CL01 and Its Promoting Effects on Watermelon(Citrullus lanatus) in Continuous Cropping Soil

作　　者：王志刚[1,2] 胡云龙[1] 徐伟慧[1] 胡影[1] 刘帅[1] 王春龙[1] 

机构地区：[1]齐齐哈尔大学生命科学与农林学院,齐齐哈尔161006 [2]哈尔滨工业大学市政环境与工程学院,哈尔滨150001

出　　处：《农业生物技术学报》2015年第10期1360-1367,共8页Journal of Agricultural Biotechnology

基　　金：农业部都市农业(南方)重点实验室开放基金(No.UA201302);黑龙江省高校科技创新团队建设计划项目(No.2013TD003)

摘　　要：解磷菌（Phosphate-solubilizing microorganisms）能够提高土壤中有效磷含量,增加土壤肥力,促进植物生长,缓解作物连作障碍。本研究从植物根际分离得到一株高效解磷菌并对其进行菌株鉴定,同时测定了其解磷和吲哚乙酸（indole acetic acid,IAA）分泌能力,及其对连作西瓜（Citrullus lanatus）幼苗生长的影响。经鉴定,筛选得到的菌株CL01为鞘氨醇单胞菌（Sphingomonas sp.）,解磷能力强,最大解磷量可达到642.60 mg/L,其IAA最大分泌量可达到22.87 mg/L,经OD600=0.5浓度菌液处理后,连作西瓜幼苗的根干重、根长、根体积、根尖个数和毛根（d=0.0~0.5 mm）比例显著增加,根系平均直径显著降低。经OD600=1.0浓度菌液处理后,连作西瓜幼苗根尖数和毛根（d=0.0~0.5 mm）比例显著增加,西瓜幼苗根系平均直径显著降低;相比较而言,低浓度菌液对连作西瓜幼苗的促生效果更好。本研究表明,经筛选鉴定的鞘氨醇单胞菌菌株Sphingomonas sp.CL01具有较高的解磷能力,可分泌IAA,且能够优化西瓜根系形态,改善根系组成,在缓解西瓜连作障碍方面具有较好的应用前景。Phosphorus Solubilizing bacteria（PSB） can improve utilization of phosphorus in soil,increase soil fertility,promote plant growth,and alleviate continuous cropping obstacle.In this study,four PSB strains were screened from the rhizosphere soil,and all of them had phosphorus solubilizing ability.By the analysis of comparisons,one of them was screened and classified as Sphingomonas sp.,named strain CL01.Further,the efficiency of phosphorus-solubilizing and the secreting level of indole acetic acid（IAA） were determined for the strain CL01,meanwhile,the effects on the root growth of watermelon（Citrullus lanatus） seedling were studied.The results showed that the strain CL01 was the strongest one on the capacity of phosphorus solubilizing than the other strains.Its maximum amount of phosphorus solubilizing was 642.60 mg/L,and the secretion level of IAA was up to 22.87 mg/L,which could promote the development of roots and growth of plants.The watermelon seedlings were treated with the bacterial suspension（in LB medium,OD600=0.5）,for30 d,the underground dry weight,root length,root volume,the number of root tips and the proportion of fibrous roots of watermelon seedlings were increased significantly compared with the controls（CK1,sterilized continuous cropping soil;CK2,unsterilized continuous cropping soil）.The underground dry weights of the seedlings were increased by 27.04% and 103.90% compared with CK1 and CK2,respectively,The root length of the seedlings were increased by 83.60% and 63.75% compared with CK1 and CK2,respectively.The root volume of the seedlings were increased by 14.29% and 100% compared with CK1 and CK2,respectively.The number of root tips were increased by 15.16% and 85.45% compared with CK1 and CK2,respectively.The proportion of fibrous roots were increased by 47.81% and 26.80% compared with CK1 and CK2,respectively.Also the average diameter of roots was decreased by 47.89% and 66% compared with CK1 and CK2,respectively.Noticeably,if the concentration of the bacterial suspension wa

关 键 词：连作障碍 解磷菌 西瓜 根系 吲哚乙酸(IAA) 

分 类 号：S651[农业科学—果树学]