The complete chloroplast genome sequence of Garcinia anomala (Clusiaceae) from Yunnan Province, China.

Garcinia anomala Planch. & Triana is an evergreen tree classified to the genus Garcinia in the family Clusiaceae. Here we report and characterize the complete chloroplast genome sequence of G. anomala and its phylogenetic relationship was investigated. The chloroplast genome is 156,774 bp in length and has a typical quadripartite chromosomal structure. The genome is divided into a pair of inverted repeat regions (IR) of 27,053 bp, one small single-copy (SSC) region of 17,082 bp and a large single copy (LSC) region of 85,586 bp. The overall GC content is 36.1%. A total of 130 functional genes were annotated, including 85 protein-coding, 37 tRNA and 8 rRNA genes. The phylogenetic analysis of G. anomala fully resolved it in a clade with four Garcinia taxa within clusioid clade of the Malpighiales.

Chloroplast phylogenomics and divergence times of Lagerstroemia (Lythraceae).

BACKGROUND: Crape myrtles, belonging to the genus Lagerstroemia L., have beautiful paniculate inflorescences and are cultivated as important ornamental tree species for landscaping and gardening. However, the phylogenetic relationships within Lagerstroemia have remained unresolved likely caused by limited sampling and the insufficient number of informative sites used in previous studies. RESULTS: In this study, we sequenced 20 Lagerstroemia chloroplast genomes and combined with 15 existing chloroplast genomes from the genus to investigate the phylogenetic relationships and divergence times within Lagerstroemia. The phylogenetic results indicated that this genus is a monophyletic group containing four clades. Our dating analysis suggested that Lagerstroemia originated in the late Paleocene (~ 60 Ma) and started to diversify in the middle Miocene. The diversification of most species occurred during the Pleistocene. Four variable loci, trnD-trnY-trnE, rrn16-trnI, ndhF-rpl32-trnL and ycf1, were discovered in the Lagerstroemia chloroplast genomes. CONCLUSIONS: The chloroplast genome information was successfully utilized for molecular characterization of diverse crape myrtle samples. Our results are valuable for the global genetic diversity assessment, conservation and utilization of Lagerstroemia.

Comparative Analysis of Six Lagerstroemia Complete Chloroplast Genomes.

Crape myrtles are economically important ornamental trees of the genus Lagerstroemia L. (Lythraceae), with a distribution from tropical to northern temperate zones. They are positioned phylogenetically to a large subclade of rosids (in the eudicots) which contain more than 25% of all the angiosperms. They commonly bloom from summer till fall and are of significant value in city landscape and environmental protection. Morphological traits are shared inter-specifically among plants of Lagerstroemia to certain extent and are also influenced by environmental conditions and different developmental stages. Thus, classification of plants in Lagerstroemia at species and cultivar levels is still a challenging task. Chloroplast (cp) genome sequences have been proven to be an informative and valuable source of cp DNA markers for genetic diversity evaluation. In this study, the complete cp genomes of three Lagerstroemia species were newly sequenced, and three other published cp genome sequences of Lagerstroemia were retrieved for comparative analyses in order to obtain an upgraded understanding of the application value of genetic information from the cp genomes. The six cp genomes ranged from 152,049 bp (L. subcostata) to 152,526 bp (L. speciosa) in length. We analyzed nucleotide substitutions, insertions/deletions, and simple sequence repeats in the cp genomes, and discovered 12 relatively highly variable regions that will potentially provide plastid markers for further taxonomic, phylogenetic, and population genetics studies in Lagerstroemia. The phylogenetic relationships of the Lagerstroemia taxa inferred from the datasets from the cp genomes obtained high support, indicating that cp genome data may be useful in resolving relationships in this genus.

Combined community ecology and floristics, a synthetic study on the upper montane evergreen broad-leaved forests in Yunnan, southwestern China.

The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous, island-like, distribution. It is diverse, rich in endemic species, and likely to be sensitive to climate change. Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan. All trees with d.b.h. > 1 cm in each plot were identified. Patterns of seed plant distributions were quantified at the specific, generic and family levels. The forests are dominated by the families Fagaceae, Lauraceae, Theaceae and Magnoliaceae, but are very diverse with only a few species shared between sites. Floristic similarities at the family and generic level were high, but they were low at the specific level, with species complementarity between plots. Diversity varied greatly among sites, with greater species richness and more rare species in western Yunnan than central Yunnan. The flora is dominated by tropical biogeographical elements, mainly the pantropic and the tropical Asian distributions at the family and genus levels. In contrast, at the species level, the flora is dominated by the southwest or the southeast China distributions, including Yunnan endemics. This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin, and has adapted to cooler temperatures with the uplift of the Himalayas. Due to great sensitivity to climate, high endemism and species complementarity, as well as the discontinuous, island-like, distribution patterns of the upper montane forest in Yunnan, the regional conservation of the forest is especially needed.