Decreasing prevalence of rhizosphere IAA producing and seedling root growth promoting bacteria with barley development irrespective of protozoan grazing regime
Decreasing prevalence of rhizosphere IAA producing and seedling root growth promoting bacteria with barley development irrespective of protozoan grazing regime
复制标题
无论原生动物放牧方式如何，随着大麦发育，根际 IAA 产生和幼苗根生长促进细菌的流行率降低
DOI：
10.1007/s11104-007-9267-8
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发表时间：
2007
期刊：
影响因子：
4.9
通讯作者：
R. Rønn
中科院分区：
文献类型：
--
作者：
Mette Vestergård;Lisa Bjørnlund;F. Henry;R. Rønn
大麦生长在土壤中，土壤中有细菌和混合原生动物群落（混合原生动物）或细菌和单一的vahlkampfiid变形虫物种（单一变形虫）。我们评估了植物年龄（播种后第29，43和57天）对根际细菌功能的两个方面的影响：（1）吲哚-3-乙酸（IAA）生产细菌的比例和（2）混合根际细菌组合对大麦幼苗根生长的影响。IAA生产者的比例显着降低，在第57天比在第29天和第43天，从根际提取的29天的老植物的混合细菌组合物的幼苗生长的危害显着低于老植物的细菌组合物。因此，这两个测定表明，从老植物的根际细菌群落比从年轻的植物的细菌群落对根的生长是不利的。采用长度异质性聚合酶链反应（LH-PCR）技术对根际细菌群落的遗传指纹图谱进行了比较。该分析显示，在第29天，从具有相当低多样性的接种物细菌群落到具有高得多的多样性的群落的明显演替。然而，多样性没有改变后，第29天，原生动物治疗，也没有植物年龄和遗传指纹之间的关系被发现。
Barley was grown in soil with either bacteria and a mixed protozoan community (Mixed protozoa) or bacteria and a single vahlkampfiid amoebal species (Single amoeba). We assessed the influence of plant age (day 29, 43 and 57 after sowing) on two aspects of rhizosphere bacterial functioning: (1) the proportion of indole-3-acetic acid (IAA) producing bacteria and (2) the effect of mixed rhizosphere bacterial assemblages on barley seedling root growth in an agar based assay. The proportion of IAA producers was significantly lower at day 57 than at day 29 and 43, and mixed bacterial assemblages extracted from rhizospheres of 29 days old plants were significantly less harmful to seedling growth than bacterial assemblages from older plants. Hence both assays indicated that bacterial communities from rhizospheres of older plants were less beneficial for root growth than bacterial communities from younger plants. Genetic fingerprinting of rhizosphere bacterial communities was compared by use of length heterogeneity polymerase chain reaction (LH-PCR). This analysis showed a clear succession from the inoculum bacterial community with a rather low diversity to a community with much higher diversity at day 29. However, diversity did not change after day 29, and no relationship between protozoan treatment nor plant age and genetic fingerprinting was found.