胶质芽孢杆菌 Bacillus mucilaginosus 的分离及对荒漠沙中棉花种子发芽的影响

摘要

对采集的土壤样品中解钾菌进行分离与鉴定，再以荒漠沙为土壤基质，加入含菌量为0、0．16、0．48、0．80、1．20、1．60（×108／CFU·mL －1）的菌液进行发芽试验，研究了解钾菌对棉花种子的发芽率、幼苗的鲜重、芽长和根长、超氧化物歧化酶（SOD）、过氧化物酶（POD）和丙二醛（MDA）含量的影响。结果表明，分离出的解钾菌为胶质芽孢杆菌（Bacillus mucilaginosus）。当沙漠土壤中加入不同含菌量的菌液后：棉花种子发芽时间提前0～24 h，发芽率随着菌含量的增加呈先增大后减少的趋势，当菌含量为0．8×108 CFU·mL －1时发芽率最高为70．29％；茎的长度增加0．5～1．2 cm，主根的长度缩短0．20～0．65 cm，但促进了侧根的生长，幼苗的鲜重提高了0．0662～0．1582 g；幼苗中的相关酶和丙二醛含量分别有不同程度的增加和减少。%The potassium bacteria obtained from collected soil samples were isolated and identified,and then the ef-fects of different contents from viable bacteria on the cotton seed germination rate,fresh weight,shoot and root length of seeding,the content of superoxide dismutase (SOD),peroxidase (POD)and malondialdehyde (MDA)were studied us-ing desert sands as soil matrixes.The results showed that the potassium bacteria was Bacillus mucilaginosus .When dif-ferent bacterial contents in bacterial liquid were added into desert soil,germination time of cotton seeds was 0 ~24 hours earlier than the control experiment.Germination rate showed a tendency to become increased first and then went de-creased with the addition of bacterial content,reaching a highest value of 70.29% when the bacterial content was 0.8 × 108 CFU·mL -1 .The length of the cotton stem and taproot were relatively increased by 0.5 ~1 .2 cm and shortened by 0.20 ~0.65 cm,respectively.However,the growth of lateral root was promoted,and the fresh weight of seedlings was increased by about 0.0662 ~0.1582 g.In the meantime,both the content of related enzymes and malondialdehyde in the seedlings became increased or decreased to some extent.