不含花序的禾本科植物样品的鉴定

Identification of grass without inflorescence collected from Korqin,Inner Mongolia

2011年9月,从内蒙古科尔沁地区采集长有真菌子座、却不长花序的禾本科植物26株。提取植物基因组DNA,合成引物扩增植物叶绿体DNA中的trnT-trnL基因间间隔序列。结果表明:内蒙古带子座植物样品与羊草的目的片段长度均为740 bp,仅4个碱基的差异;而新麦草属的Psathyrostachys fragilis目的片段长度为1 750 bp,与带子座样品及羊草的碱基差异较大。系统发育树分析表明带子座植物样品与羊草聚为一支,自展值95%。利用组织透明法观察植物的叶表皮微形态,内蒙古带子座植物样品同样与羊草叶表皮微形态一致。结合植物学形态特征、trnT-trnL基因片段分析及叶表皮微形态,内蒙古带子座禾本科植物被鉴定为羊草(Leymus chinensis Trin.)。野外条件下,具有宿主特异性的内生真菌能在羊草植株上形成子座,国际上还未见相关报道,也显示羊草植株的特异性。

On September 2011,26 infertile grasses with stromata were collected from Korqin, Inner Mongolia. A PCR-based approach was used to identify these plants. Alignment analysis conducted by DNAssist indicated sequences of these plants and Leymus chinensis were 740 bp, with only four bases different in coverage,while sequence of Psathyrostaehys fragilis was 1 750 bp with distinct base difference. Pbylogenetic tree based on trnT-trnL intergenie space from epDNA region revealed that these plants clustered with Leymus chinensis with a bootstrap value of 95%. Leaf epidermis micromorphology was observed by tissue clearing method. Micromorphology of these plants was also consistent with Leymus chinensis, different from others. In combination of trnT-trnL intergenic space analysis and leaf epidermis, plants with stromata collected from Korqin were identified as Leymus chinensis Trin. The host specific fungal endophyte which develops stromata on Leymus chinensis in nature had no record. This could be another criterion to distinguish Leymus chinensis plants from other plants.