棉花新材料A111基于cpDNA的种性初步鉴定

A111是从澳大利亚收集到的一份新的野生棉，属于澳洲棉、或奈尔逊氏棉乃至一个新的棉种，归属一直没定论。为鉴别A111与澳大利亚以及世界其它地区棉种的差别，以24个棉种（变种）为参照，分析了A111的cpDNA序列特点。结果表明，在15条cpDNA基本序列中，筛选出了8条序列适合于棉属植物系统发育和种性鉴别研究。这8条序列的变异率和识别率均较高，其中rps16识别率最高(100%)。基于8个序列组合的系统发育分析，能识别单个棉种。聚类结果显示，棉属分为两大分支，A111与奈尔逊氏棉（G3）处于澳洲野生棉分支中的姊妹分支。序列比对结果表明，A111的叶绿体序列存在特异的插入与缺失，明显区别于其他棉种。由此，初步鉴定A111是澳洲野生棉的一个新种，与奈尔逊氏棉的亲缘关系最近。

Preliminary Identification of A111 as a New Species in Gossypium Based on Chloroplast Sequences

A111 is a new cotton material in Gossypium collected from Australia and its taxonomy classification is still unknown. To identify its differences with extant Gossypium species from Australia and other parts of the world, its cpDNA properties by referencing other 24 Gossypium species (or varietas) were analyzed in this paper. The results showed that 8 out of 15 candidates cpDNA fragments were suitable for phylogenetic analysis and identification of Gossypium spp. based on their higher variety and higher species resolution. Among the fragments, rps16 exhibited the highest species resolution (100%). The phylogenetic analysis based on the combination of 8 cpDNA fragments had successfully distinguished each species. The phylogenetic analysis revealed that there were 2 main clades in Gossypium and A111 was the sister to G. nelsonni on the branch of Australian G genome. However, A111 owned some special InDels, which was completely different from the other Gossypium species after sequence alignment. In conclusion, our results suggested that A111 may be a new Gossypium species from Australia after preliminary identification and has a close genetic relationship with G. nelsonni.