Zhang X X, Kosier B, Priefer U B
Okologie des Bodens, RWTH Aachen, Worringer Weg 1, 52060 Aachen, Germany.
Mol Ecol. 2001 Sep;10(9):2297-305. doi: 10.1046/j.0962-1083.2001.01364.x.
A total of 360 Rhizobium leguminosarum bv. viciae strains was isolated from three brown-coal mining restoration fields of different age and plant cover (without and in the first and second year of alfalfa, Medicago sativa, cultivation) using two host species (Vicia hirsuta and Pisum sativum) as capture plants. The strains were genetically typed by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-generated 16S-23S ribosomal DNA intergenic spacer regions (IGS-RFLP) and characterized by plasmid profiles and RFLP analysis of amplified nodABC genes. The R. leguminosarum bv. viciae population was dominated by the same group of strains (irrespective of the trap plant used). According to type richness, the genetic diversity of indigenous R. leguminosarum in the second year of restoration was lower than in the first year and it resembled that of the fallow field, except for plasmid types, in which it was higher than that of the fallow field. Some of the less frequent nodABC genotypes were associated with distinct chromosomal IGS genotypes and symbiotic plasmids (pSyms) of different sizes, indicating that horizontal transfer and rearrangements of pSym can occur in natural environments. However, the dominant pSym and chromosomal genotypes were strictly correlated suggesting a genetically stable persistence of the prevailing R. leguminosarum bv. viciae genotypes in the absence of its host plant.
利用两种寄主植物（硬毛野豌豆和豌豆）作为诱捕植物，从三个不同年份和植被覆盖情况（未种植和苜蓿种植第一年及第二年）的褐煤开采复垦地共分离出360株豌豆根瘤菌蚕豆生物型菌株。通过聚合酶链反应（PCR）扩增的16S - 23S核糖体DNA基因间隔区（IGS - RFLP）的限制性片段长度多态性分析对菌株进行基因分型，并通过质粒图谱和扩增的nodABC基因的RFLP分析进行特征鉴定。无论使用哪种诱捕植物，豌豆根瘤菌蚕豆生物型群体均以同一组菌株为主。就类型丰富度而言，复垦第二年本地豌豆根瘤菌的遗传多样性低于第一年，除了质粒类型，其与休耕地相似，在质粒类型方面，复垦地高于休耕地。一些频率较低的nodABC基因型与不同大小的独特染色体IGS基因型和共生质粒（pSyms）相关，表明pSym在自然环境中可发生水平转移和重排。然而，占主导地位的pSym和染色体基因型严格相关，表明在没有寄主植物的情况下，优势豌豆根瘤菌蚕豆生物型基因型具有遗传稳定性。
