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通过3种PCR技术测定基因特征和测定3种生化特征,对来自南澳洲两块对比小麦田土壤中的Pseudomonasbrassicacearum种群的菌株进行了分析研究。结果显示,两种不同土壤和两种不同根部区域(根表和根际),该种群具有高度多样性,其基因型和基因组也具有显著差异(P<0.05)。所分离到的菌株中,四分之三具有独特的基因组,90%以上的基因组是其原种群所独具有的。所有菌株的基因组的平均同源性比较低(22%),聚类分析不能证明来自不同小麦田和不同根部区域的菌株具有亲缘性。聚类分析显示,种群内的基因流动是受到限制的,菌株基因组的差异是由于基因的随机漂流引起的,由根表得到的基因型是与所采集的对比土壤相关联的。有三分之一的菌株检测到了2,4二乙酰基均苯三酚(PhlD)生物合成基因,这些菌株形成了一相关联的组群(同源性为60%)。4株产生PhlD的菌株(两种野生型,表型不同)对小麦全蚀病和腐霉引起的油菜根腐病具有显著的防治效果,展现出了对这类病原菌引起的根部病害的防治潜能。
Three strains of Pseudomonas brassicacearum in soil from two comparative wheat fields in South Australia were analyzed by three PCR techniques to determine the genetic characteristics and determine three biochemical characteristics. The results showed that there were significant differences in genotypes and genomes between two different soils and two different root regions (root and rhizosphere) (P <0.05). Three-quarters of the isolated isolates have unique genomes, and more than 90% of the genome is unique to their original population. The average genome homology of all isolates was low (22%), and cluster analysis did not prove that the isolates from different wheat fields and different root regions were endemic. Cluster analysis showed that the flow of genes within the population was limited. The differences in the genome of the strains were due to random rafting of the genes. The genotypes from the root list were correlated with the soils that were collected. One third of strains detected the 2,4-diacetyl pyrogallol (PhlD) biosynthetic genes that formed an associated cohort (60% homology). Four strains producing PhlD (two wild type and different phenotype) had significant control effects on total eclipses and Pythium-induced root rot in rapeseed and showed the potential of controlling root diseases caused by such pathogens .