The complete chloroplast genome of Chimonobambusa hejiangensis (Poaceae: Arundinarieae) and phylogenetic analysis.

Chimonobambusa hejiangensis is a kind of bamboo that has excellent edible and economic value, which is endemic to southwest China. The study used next-generation sequencing to obtain the complete chloroplast (cp) genome sequence of C. hejiangensis. The cp genome of C. hejiangensis has a total length of 138,908 bp, and consisted of an 82,495-bp large single-copy region, an 12,743-bp small single-copy region, and two 21,835-bp IR regions. In total, 112 unique genes were found in the cp genome, including 77 protein coding, 31 tRNA, and 4 rRNA genes. Phylogenetic analysis indicated that C.hejiangensis and C. tumidissinoda are sister species within the Arundinarieae genus, where Chimonocalamus and Ampelocalamus are more closely related to them.

Phylogeography of the rare and endangered lycophyte Isoetes yunguiensis.

BACKGROUND: Isoetes yunguiensis Q. F. Wang & W. C. Taylor is a lycophyte of an ancient genus, and it is endemic to China. It is a first-class protected plant in China. This living fossil is used in paleoecology and studies on the evolution of Lycophytes in the Yunnan-Guizhou Plateau. In recent years, human activities have caused the disappearance of several wild populations, and the number of plants in the existing populations is low. Study of the genetic structure, distribution pattern, and historical dynamics of I. yunguiensis in all areas of its distribution is of guiding significance for its rational and effective protection. METHODS: Expressed sequence tag-simple sequence repeat (EST-SSR) markers were used to study the genetic diversity and structure of I. yunguiensis, and noncoding chloroplast DNA (cpDNA) sequences were used to study the pedigree, population dynamics history, and glacial shelter of I. yunguiensis. A maximum entropy model was used to predict the past, present, and future distribution patterns of I. yunguiensis. RESULTS: Analysis with EST-SSR markers revealed that I. yunguiensis showed high genetic diversity and that genetic variation was significantly higher within populations than between populations. Based on cpDNA data, it was concluded that there was no significant geographic pedigree in the whole area of I. yunguiensis distribution (NST = 0.344 >  GST = 0.183, p > 0.05); 21 haplotypes were detected using DnaSP v5. Neutral test and LAMARC simulation showed that I. yunguiensis has experienced rapid expansion in recent years. The maximum entropy model predicted that the potential distribution area of I. yunguiensis in the last glacial maximum period has increased significantly compared with the present distribution area, but the future distribution area did not show substantial changes.