Genetic variability and population structure of Disanthus cercidifolius subsp. longipes (Hamamelidaceae) based on AFLP analysis

Transcriptomic and metabolic analysis unveils the mechanism behind leaf color development in Disanthus cercidifolius var. longipes

Introduction: Leaf coloration in Disanthus cercidifolius var. longipes results from the interplay of various pigments undergoing complex catalytic reactions. Methods: We aimed to elucidate the mechanisms of pigment biosynthesis affecting leaf color transition in D. cercidifolius var. longipes by analyzing variations in pigment accumulation and levels of gene expression. Results: We identified 468, 577, and 215 differential metabolites in green leaves (GL), gradual-color-changing leaves (GCCL), and red leaves (RL), respectively, with 94 metabolites shared across all comparisons. Metabolite accumulation patterns were similar among GL, GCCL, and RL, with flavonoids being the main differential metabolites. Delphinidin, malvidin, and petunidin derivatives were mostly accumulated in GCCL, whereas cyanidin, pelargonidin, and peonidin derivatives accumulated in RL. Transcriptome sequencing was used to identify differentially expressed genes. The expression of anthocyanin biosynthetic pathway genes was associated with anthocyanin accumulation patterns. Discussion: Our findings reveal that the content of delphinidin, malvidin, petunidin, and carotenoids collectively determines the gradual transition of leaf color from green in spring and summer to green, purple, and orange-yellow in early autumn, whereas the content of cyanidin, peonidin, pelargonidin, and carotenoids together causes the autumnal transition to red or orange-red colors as leaves of D. cercidifolius var. longipes age.

Characterization and phylogenetic analysis of the complete chloroplast genome sequence of Disanthus cercidifolius subsp. longipes (Hamamelidaceae), a rare and endangered wild plant species in China

Disanthus cercidifolius subsp. longipes is a rare and endangered plant species. In our study, the complete chloroplast genome was assembled by using high-throughput DNA sequencing data. The whole CP genome is 158,076 bp in length, comprising of a large single-copy region of 87,148 bp, a small single-copy region of 18,300 bp, and two inverted repeat regions of 26,314 bp each. There are 136 genes in the genome, including 86 protein-coding genes, 40 transfer RNA genes, eight ribosomal RNA genes, and two pseudogenes (ndhK and ycf1). Phylogenetic results demonstrated that D. cercidifolius subsp. longipes grouped with other Hamamelidaceae species, with a support rate of 100%.

Isolation and identification of EST-SSR markers in Chunia bucklandioides (Hamamelidaceae)

PREMISE OF THE STUDY

Chunia bucklandioides (Hamamelidaceae), endemic to Hainan, China, is listed as threatened in the IUCN Red List and is now only found on Mt. Diaoluo and Mt. Jianfeng. Thus, microsatellite markers were developed for future conservation genetic studies of this species.

METHODS AND RESULTS

A total of 115 primers were designed on the basis of the transcriptome data of C. bucklandioides. Of them, 59 successfully amplified in C. bucklandioides and polymorphisms were detected in 11; the number of alleles per locus varied from two to five, the observed heterozygosity ranged from 0.000 to 0.941, and the expected heterozygosity ranged from 0.000 to 0.699. A total of 13 primers amplified in Mytilaria laosensis, and five primers amplified in Exbucklandia tonkinensis and E. populnea.

CONCLUSIONS

The markers screened here provide a basis to assess genetic structure and further establish conservation strategies for C. bucklandioides.

Yalongjiang River Has Had an Important Role in the Dispersal and Divergence of Rosa soulieana in the Hengduan Mountains of China

The Hengduan Mountains are the core of the Sino-Himalayan Floristic Region. Rosa soulieana Crép. is an important wild rose species that is widely distributed in the Hengduan Mountains. To provide better future utilization of this wild rose, and also to add some possible proof of the effect of geomorphological and ecological characteristics of the Hengduan Mountains on the current spatial distribution and genetic diversity of local species, the genetic diversity and genetic structure of 556 individuals from 37 populations of R. soulieana were studied using fluorescent amplified fragment length polymorphisms (AFLPs). R. soulieana showed a moderately high level of genetic diversity and a high level of genetic differentiation at the species level. The total percentage of polymorphic loci, total heterozygosity (Ht), Shannon index (I), and heterozygosity value within populations (Hs) were 97.8%, 0.253, 0.339, and 0.139, respectively. More than half of the total genetic variation (54.0%) occurred within populations, and the overall gene differentiation coefficient (Gst) was 0.451. The genetic differentiation among populations was positively and significantly correlated with geographic distance. The neighbor-joining cluster and the Bayesian analysis divided all the populations and individuals into 3 groups, and did not support the morphology based intraspecific varieties. The results confirmed that the ancient R. soulieana of the third group survived in northwestern Yunnan and Yalongjiang valley and then moved upnorth along the valley. The spatial distribution of the other two groups was the result of allopatric divergence due to long period of adaptation to the different climatic conditions of its distribution at either side of the Yalongjiang River.