Huang Shijie, Yu Guojing, Wang Yong, Gao Huibin, Hui Chaomao, Vasupalli Naresh, Lin Xinchun
National Key Laboratory for Development and Utilization of Forest Food Resources, Zhejiang A & F University, Lin'an, Hangzhou, Zhejiang, 311300, China.
Key Laboratory of Bamboo Science and Technology of Ministry of Education, Bamboo Industry Institute, Zhejiang A & F University, Lin'an, Zhejiang, 311300, China.
BMC Plant Biol. 2025 Sep 1;25(1):1177. doi: 10.1186/s12870-025-07199-x.
The bamboo species Dendrocalamus × mutatus T.P.Yi & B.X.Li (D. mutatus) holds great economic and ecological importance in China. Although previously D. mutatus was presumed to be a hybrid of Bambusa grandis and Bambusa pervariabilis, its taxonomic status has remained uncertain. Therefore, we combined plastomes and nuclear SSR datasets, in addition to morphological data, to refine our understanding of the taxonomic status of D. mutatus.
The chloroplast genome of D. mutatus exhibits a typical quadripartite structure, comprising a large single-copy region (LSC), a small single-copy region (SSC), and two inverted repeat regions (IRa and IRb), containing a total length of 139,432 bp. Comparative genomic analyses revealed extremely high similarity between D. mutatus and D. yunnanicus, differing by only two single-nucleotide polymorphisms (SNPs). In contrast, a greater divergence was observed when compared with D. sikkimensis (six SNPs and one four-base insertion). Phylogenetic reconstruction using the Maximum Likelihood and Bayesian Inference method based on chloroplast genomes strongly supported the close relationship between D. mutatus and D. yunnanicus, while distinctly separating them from the previously proposed parent species Bambusa grandis and Bambusa pervariabilis. Morphological comparisons further confirmed the similarity between D. mutatus and D. yunnanicus, particularly with respect to the absence of conspicuous culm sheath auricles and oral setae, as well as the lack of fimbriate hairs on the ligule. Nuclear SSR marker analyses also showed identical predominant allele at the SSR 23 and 24 loci between D. mutatus and D. yunnanicus. Collectively, the comprehensive integration of chloroplast genome data, nuclear SSR evidence, and morphological observations supports the conclusion that D. mutatus is a synonym of D. yunnanicus rather than a hybrid of Bambusa grandis and Bambusa pervariabilis.
This research provides a comprehensive understanding of the chloroplast genome of D. mutatus, providing valuable insights that enhance the taxonomic resolution and conservation strategies for bamboo species.
巨龙竹（Dendrocalamus × mutatus T.P.Yi & B.X.Li，即D. mutatus）在中国具有重要的经济和生态价值。尽管之前认为巨龙竹是大绿竹（Bambusa grandis）和青皮竹（Bambusa pervariabilis）的杂交种，但其分类地位仍不明确。因此，我们结合了叶绿体基因组和核SSR数据集以及形态学数据，以深化对巨龙竹分类地位的认识。
巨龙竹的叶绿体基因组呈现典型的四分体结构，由一个大单拷贝区域（LSC）、一个小单拷贝区域（SSC）和两个反向重复区域（IRa和IRb）组成，全长139,432 bp。比较基因组分析显示，巨龙竹与云南龙竹（D. yunnanicus）之间具有极高的相似性，仅存在两个单核苷酸多态性（SNP）差异。相比之下，与西藏巨龙竹（D. sikkimensis）比较时观察到更大的差异（六个SNP和一个四碱基插入）。基于叶绿体基因组，使用最大似然法和贝叶斯推断法进行的系统发育重建有力地支持了巨龙竹与云南龙竹的密切关系，同时将它们与之前提出的亲本物种大绿竹和青皮竹明显区分开来。形态学比较进一步证实了巨龙竹与云南龙竹之间的相似性，特别是在没有明显的竿箨耳和口缘刚毛以及叶舌上没有流苏状毛方面。核SSR标记分析还显示，巨龙竹和云南龙竹在SSR 23和24位点的优势等位基因相同。总体而言，叶绿体基因组数据、核SSR证据和形态学观察的综合整合支持了巨龙竹是云南龙竹的异名而非大绿竹和青皮竹杂交种的结论。
本研究全面了解了巨龙竹的叶绿体基因组，提供了有价值的见解，提高了竹种的分类分辨率和保护策略。
