小麦根际解钾细菌的分离筛选及鉴定
时间:2017-06-07 11:54 来源:毕业论文 作者:毕业论文 点击:次
| 摘 要：从周口市川汇区小麦根际土壤中筛选出9株解钾细菌，具有明显透明圈的有3株（K1、K3、K7）。采用原子吸收法测定其解钾活性，96 h后各培养基中K+的含量在4.37 %～13.01 %之间，最高的是菌株K7（13.01 %），其次是菌株K3（11.78 %）和K1（10.05 %）。同时通过菌体特征观察、菌落形态观察和生理生化鉴定，确定3种菌株属于胶质类芽孢杆菌。通过盆栽试验，对相关数据进行分析，3种菌株均能促进小麦的生长。与空白组相比，菌株K7提高了小麦的出苗率、根长、根重、株高、鲜重，分别达到13.58%、33.90%、35.83%、36.96%、47.51%，菌株K3与空白组相比，对应提高14.81%、32.20%、31.02%、27.72%、38.62%，菌株K1对小麦的促生效果最低，与空白组相比，对应提高7.41%、13.90%、23.95%、21.72%、28.58%。研究表明，菌株为K3和K7为高效解钾菌。关键词：解钾细菌；筛选；鉴定；解钾活性；盆栽实验9797 Isolation,Screening and Identification of Potassium-releasing Bacteria from Wheat Rhizosphere Abstract: Nine potassium-releasing bacterias were isolated from wheat rhizosphere soil collected from Chuan Hui region, Zhou Kou city. Among them, 3 strains had transparent circle, which were named K1、K3 and K7. The ability of potassium dissolving of every strain was measured by the atomic absorption method. 96 hours late, the K+ mass concentration of each culture medium were between 4.37% and 13.01%, and K7 had the highest ability of releasing potassium(13.01%), next were K3(11.78%) and K1(10.05%). The three bacterias were identified into Bacillus muciaginosus based on their feature, morphological and physiological and biochemical properties. In pot experiment, after primary and secondary test, the three potassium-releasing bacterias could promote the growth of wheat. Strain K7 treatments showed 13.58% increasing on wheat emergence, 13.56% increasing on root length, 23.95% increasing on root weight, 21.78% increasing on plant height(apart root), 28.58% increasing on total fresh weight, and strain K3 could increase the correspondents by 14.81%, 32.20%, 31.02%, 27.72%, 38.62%. The growth-promoting effection of K1 was the last, they were 7.41%, 13.56%, 23.95%, 21.78%, 28.58%. In conclusion, K3 and K7 were highly-active potassium-releasing bacteria. Key words：Potassium-releasing bacteria；Isolate；Identification；The ability of potassium dissolution；The pot experiment. 目 录 摘 要 1 引 言 2 1 材料与方法 3 1.1 材料 3 1.2 方法 4 2 结果与分析 6 2.1 解钾细菌的筛选 6 2.2 解钾细菌的初步鉴定 7 2.3 盆栽试验结果 9 3 讨论 10 4 结论 11 参考文献 12 致 谢 14小麦根际解钾细菌的分离筛选及鉴定引 言 钾是植物所必须的大量营养元素之一。缺钾会造成植物根系短而少，易早衰，而根系发育的好坏直接决定着植物吸收土壤养分能力的高低[1]，进而影响植株的生长发育，造成作物产量低、抗逆性差，且极易发生倒伏[2]。利用化肥补钾是我国农业生产中普遍使用、见效快的土壤有效钾补充方法，但长期过量使用化肥会影响土壤结构[3]，导致养分流失，造成环境污染。随着农业的迅速发展，我国约有60％的耕地缺钾，耕地速效钾含量迅速下降[4]，造成土壤中氮、磷、钾3种元素比例严重失调，制约了农业发展。另一方面，我国以钾长石为主的难溶性矿石资源却十分丰富，分布广泛，在黑龙江、湖北、辽宁、陕西、四川、云南、广西等省均有矿藏，总储量近100亿吨[5]。但是，可供作物吸收利用的速效性钾不超过全钾2％，而在一定条件下，矿物态钾、缓效性钾与速效性钾之间可以相互转化，存在动态平衡[6]。因此，可利用高效的解钾菌将土壤中的矿物态钾转变为速效性钾，供作物吸收利用。 (责任编辑：qin) |