A preliminary analysis of phylogenetic relationships of Arundinaria and related genera based on nucleotide sequences of nrDNA （ITS region） and cpDNA （trnL-F intergenic spacer）

Phylogenetic relationships of Arundinaria and related genera (Pleioblastus, Pseudosasa, Oligostachyum, Bashania, Clavinodum, etc.) were assessed by analyzing the sequences of the nrDNA internal transcribed spacer (ITS) and the cpDNA trnL-F intergenic spacer (IGS). Comparison with trnL-F IGS sequence, the ITS region provided the higher number of parsimony informative characters, and the interspecific variation of the ITS sequence was higher than that of the trnL-F IGS sequence.The tree obtained by combining both sets of data showed that the species sampled in Arundinaria and the related genera were monophyletic and divided into two clades. The relationships and positioning of all the taxa surveryed (including A. oleosa, A. hsienchuensis, A. chino, A. amara, A. yixingensis, A. amabilis, A. fortunei, A. pygmaea, A. gramineus, A. fargesii, A. faberi, A. hupehense, Pseudosasa japonica cv. Tsutsumiana, P. japonica and Brachystachyum densiflorum) were also discussed. The results from the sequences were broadly consistent with morphological characters, appearing all these taxa sampled belong to the genus of Arundinaria. The topologies of the trees generated from individual data and the combined data were similar.

正阳县花生根瘤菌遗传多样性及其共生特性研究

从河南省正阳县土壤中捕捉67株根瘤菌,根据IGS-RFLP结果分成9个基因内间隔区(intergenic spacer,IGS)类型,通过16S rRNA基因序列系统发育分析鉴定菌株为慢生根瘤菌属(Bradyrhizobium),并依据持家基因多位点序列分析(multilocus sequence analysis,MLSA)结果将其分成7个簇(Clusters)。其中,Clusters 1被鉴定为广东慢生根瘤菌(B.guangdongense),Clusters 2、3、4、5和6分别被鉴定为慢生根瘤菌属的疑似新种群B.genospeciesⅡ、Ⅲ、Ⅳ、Ⅴ和Ⅵ。选取11个代表菌株,结瘤基因nodA序列与广东慢生根瘤菌CCBAU 51649T和广州慢生根瘤菌(B.guangzhouense)CCBAU 51670T聚为相同分支,宿主均为花生。所有代表菌株均能与花生植株共生结瘤,且叶绿素含量、地上部干质量和地下部干质量、株高度、根长度与对照相比均有显著提升,其中接种ZB30的处理组的地上部干质量是对照组的2.7倍。