放线菌定殖及其对马铃薯根区土壤微生物的影响

Colonization of Actinomycetes and Their Effect on Microorganisms in Rhizosphere Soil of Potato

为探究放线菌Act11、Act12及G5对盆栽马铃薯根区土壤微生物组成、数量的影响,及其在根区土中的定殖情况,采用盆栽拌土接种Act11＋Act12混合放线菌剂和G5放线菌剂进行试验。收获期采用稀释平皿法对根区土中细菌、真菌及放线菌进行分离测数,采用16SrRNA序列分析方法对优势细菌和放线菌进行鉴定。结果表明,拌土接入Act11＋Act12混合放线菌剂和G5放线菌剂后,根区土壤中微生物数量发生如下变化：细菌总数较对照分别减少30.5%（P〈0.05）和28.0%（P〈0.05）,真菌总数较对照分别减少17.9%和45.8%,放线菌总数较对照分别增加44.1%（P〈0.05）和4.1%;放线菌与真菌数量比A/F较对照分别提高75.4%和92.4%;优势细菌JB1、JB2、JB3及优势放线菌JA3、JA4、JA5数量较对照分别减少18.7%-100.0%及0.4%-100.0%;经鉴定JB1为耐盐节杆菌（Arthrobacter pascens）,JB2为飞禽岛海草球菌（Phycicoccus bigeumensis）,JB3为黄金节杆菌（Arthrobacter aurescens）,JA3为德克萨斯糖丝菌（Saccharothrix texasensis）,JA4为新疆糖丝菌（Saccharothrix xinjiangensis）,JA5为淀粉酶产色链霉菌（Streptomyces diastatochromogenes）;（Act11＋Act12）和G5在根区土的定殖率分别为34.4%和45.9%。供试3株生防放线菌拌土接种对盆栽马铃薯根区土壤微生物区系均有显著影响,接入菌在马铃薯根区土中的定殖能力均较强。

The objective of this study is to explore the effect of actinomycetes Act11,Act12 and G5on composition and quantity of microorganisms in rhizosphere soil of potted potato,and colonization of these actinomycetes.Soil inoculation with mixed actinomycetic agent of Act11 and Act12,and G5 actinomycetic agent was conducted via pot trial.Serial dilution and plating techniques were used to isolate and count the quantity of soil bacteria,fungi and actinomycetes from potato rhizosphere soil during the harvest time.The dominant bacteria and actinomycetes were identified by 16 SrRNA sequence analysis.Results showed that quantity of microorganisms in potato rhizosphere soil changed after soil inoculation with mixed actinomycetic agent of Act11 and Act12,and G5 actinomycetic agent：compared with the control treatment,the number of soil bacteria decreased by 30.5%（P〈0.05）and 28.0%（P〈0.05）,respectively,and the number of soil fungi reduced by 17.9% and 45.8%,respectively,whereas the number of soil actinomycetes increased by 44.1%（P〈0.05）and 4.1%,respectively.The ratio between actinomycetes and fungi A/F increased by 75.4% and 92.4%,respectively,compared with the control treatment.The number of dominant bacteria JB1,JB2,JB3 and dominant actinomycetes JA3,JA4,JA5 decreased by 18.7%-100.0% and 0.4%-100.0%,compared with the control treatment.Identification showed that JB1 is Arthrobacter pascens,JB2 is Phycicoccus bigeumensis,JB3 is Arthrobacter aurescens,JA3 is Saccharothrix texasensis,JA4 is Saccharothrix xinjiangensis,and JA5 is Streptomyces diastatochromogenes.Colonization rates of Act11＋Act12and G5 in potato rhizosphere soil were 34.4% and 45.9%,respectively.In conclusion,all the tested three biocontrol actinomycetes had significant effect on the rhizosphere soil microflora after soil inoculation in pot trail,and all the inoculated actinomycetes colonized well in the rhizosphere soil of potato.