In order to study the genetics of local adaptation in all main deserts of northwest China, whole genomes of 169 individuals were resequenced, which covers 20 populations of Zygophyllum loczyi (Zygophyllales: Zygophylaceae). We describe more than 15 million single nucleotide polymorphisms and numerous InDels. The expected heterozygosity and PIC values associated with local adaptation varied significantly across biogeographic regions. Variation in environmental factors contributes largely to the population genetic structure of Z. loczyi. Bayesian analysis performed with STRUCTURE defined four genetic clusters, while the results of principle component analysis were similar. Our results shows that the Qaidam Desert group appears to be diverging into two branches characterized by significant geographic separation and gene flow with two neighboring deserts. Geological data assume that it is possible that the Taklamakan Desert was the original distribution site, and Z. loczyi could have migrated later on and expanded within other desert areas. The above findings provide insights into the processes involved in biogeography, phylogeny, and differentiation within the northwest deserts of China.
Various species from the genus Calligonum L. are widely used in erosion control in Northwest China. Their widespread use and breeding efforts highlight the need for the conservation of the high-quality germplasm resources of this genus. To assess genetic diversity, the genome of Calligonum junceum was screened, and 380,328 SSR loci were identified. After further screening, 17 microsatellite markers were identified and transferred to 11 other species of the genus. When analyzed together, the 11 species showed significant discrimination power (PIC = 0.623), and we detected that the mean number of alleles per locus was 2.684, the overall heterozygosity observed value was 0.295, and the expected heterozygosity (He) was 0.373. Genetic diversity in Calligonum mongolicum was the highest at I = 1.305, He = 0.647, and that of Calligonum gobicum was the lowest at I = 0.127, He = 0.072. The results of this study provide reference SSR primers for the genus Calligonum, supporting the improvement of its germplasm conservation efforts.
Ammopiptanthus nanus, a Tertiary-era endangered plant, is of great scientific value. In this research, we focus on A. nanus population dynamics in an effort to bridge the divide between micro genetic variation and a macroscopic ecological pattern of distribution. The population structure of 129 wild specimens of A. nanus from eight populations was analyzed using EST-SSR molecular markers in this research. The Mantel test and RDA analysis have been used in this research to investigate the factors that influence the genetic diversity of A. nanus. Using 15 pairs of SSR primers, a total of 227 alleles were detected in 129 samples from 8 populations. The mean number of alleles was 17, and the average expected heterozygosity was 0.405. It is shown that wild A. nanus is divided into six individual populations. A. nanus are significantly affected by wind speed in terms of the variation of genetics. It is suggested that a nature conservation area for A. nanus be established as soon as possible, based on our results and the current natural distribution of the species. It is necessary to focus on the issue of pests and diseases while simultaneously preventing the continuation of anthropogenic woodcutting and disaster. Manual seedling collection should be employed in regions where the environment permits. Through making use of manual breeding techniques, this will contribute to the growth of the natural population of A. nanus.