恶臭假单胞细菌与紫花苜蓿在泥炭培养体中结合定殖研究

在植物根系定殖外源微生物是促进植物健康生长和污染土壤修复的重要方法,而植物根部存在适宜的生长空间是外源微生物定殖的关键。利用泥炭是植物和微生物优良的培养基质的特点,将泥炭作为外源微生物和植物根部的结合体,研究在播种时期接种和露根时期接种条件下,恶臭假单胞细菌(AB-92019)在泥炭与苜蓿根系构成的定殖环境中的定殖动态和定殖密度。结果表明:2种定殖时期在泥炭体的定殖效果有明显不同,露根时期接种后第20 d的定殖密度为6.10 logcfu/g干泥炭;播种时期接种定殖密度下降较快,第20 d的定殖密度为5.62 logcfu/g干泥炭。而在苜蓿根系20 d后的定殖密度,播种时期接种(3.90 logcfu/g鲜根)高于露根时期接种(3.03 logcfu/g鲜根)。并且2种时期定殖都不影响苜蓿正常的生长。

Pseudomonas putida Colonization in Alfalfa Rhizosphere under Peat Substrate Condition

Bacterial colonization in rhizosphere is an important measure of healthy growth of plant and remediation of polluted soil,however,an effective inoculation of rhizosphere needs well growing space.On the basis of peat being excellent culture medium of plant and microbe,peat was produced in a cylinder(r=2.5 cm,h=3 cm) as a conjunct substrate of alfalfa and P.putida(AB-92019).Culture experiment was conducted to investigate the inoculation density and dynamics of P.putida in peat substrate and alfalfa roots with two inoculated periods,inoculation seedtime(IST) and inoculation of root coming out the peat cylinder time(IRPT).The results showed that the colonization dynamics and the density of IRPT in peat were different from IST,the colonization density of IRPT reached 6.10 log cfu/g dry peat 20 days after,and that of IST decreased rapidly and achieved 5.62 log cfu/g dry peat 20 days afterwards.However,the inoculation density of IST(3.90 log cfu/g dry root) in alfalfa roots was more than that of IRPT(3.03 log cfu/g root) 20 days after.The growth of alfalfa was not influenced by two inoculation methods.