The common walnut (Juglans regia L.), a species of significant economic and ecological importance, along with its variant, holds developmental value. Simple sequence repeat (SSR) markers are used as an effective method for material identification due to their co-dominant inheritance. In this work, a total of 357629 SSR loci were searched based on previously published walnut genome sequences, with a density of 662.28 (SSRs/Mb). The majority of all these loci were found to be single nucleotide A/T (58.49%), followed by the dinucleotide AT (19.48%). Based on the results of genome-wide SSR site design, 22 effective primer pairs were designed and screened to analyze the genetic diversity of 48 wild walnut samples from three countries. Each locus had an average of 5.17 effective alleles (Ne), with an average polymorphism information content (PIC) of 0.71, average heterozygosity (He) of 0.52, and average genetic differentiation index (Fst) of 0.09. The analysis of 48 wild walnut samples from three countries (Kyrgyzstan, Tajikistan, and China) using the unweighted pairwise clustering method and arithmetic mean (UPGMA) along with principal coordinate analysis revealed the division of all samples into three groups. In summary, these novel SSR markers serve as a reference for the identification of wild walnut germplasm in Central Asia and for the development and utilization of wild walnut seed resources.

Background/Objectives: Desert plants exhibit remarkable resilience to extreme environments, and their capacity for population establishment is noteworthy. However, the adaptation process mechanisms of those plants to harsh habitats, particularly concerning intraspecific differentiation and genetic diversity, remain poorly understood, and a comprehensive framework is lacking. Zygophyllum loczyi Kanitz, an annual or biennial desert herb, demonstrates significant phenotypic plasticity across diverse habitats. Methods: Using mixed-effects models, this study examined 20 populations from four deserts to assess phenotypic variation and predict trait_environment relationships. Results: The findings indicated substantial inter-population phenotypic differentiation in Z. loczyi, with greater variation observed between deserts than within them. Traits such as blade length, petal length, sepal length, and stamen length were influenced by environmental conditions. Mixed-effects model prediction showed that the growth location of Z. loczyi significantly impacted its phenotypic traits. The characteristics of the four desert populations displayed varying responses to temperature and moisture changes, with the most pronounced response noted in the Gurbantunggut desert (Gt) population, indicating that survival stress has an important influence on the performance of plants. The single nucleotide polymorphisms result further confirmed that the differentiation and genetic diversity of the Gt population displayed the highest selection pressure, resulting the small effective size of the population. Conclusions: This study uncovers the adaptive mechanism of Z. loczyi to habitat through investigating the inter-population phenotypic differentiation and genetic diversity and provides new insight into local adaptation and evolutionary processes in the desert environment.

This study systematically investigated the genetic characteristics and germplasm conservation strategies of Xinjiang Thompson Seedless grapes (Vitis vinifera Thompson Seedless) and Munake grapes (Vitis vinifera L. cv. Munake) using SSR molecular markers and whole-genome resequencing technology. A genetic diversity analysis of 165 Thompson Seedless accessions with 16 SSR markers identified 442 alleles (27.63 alleles per locus on average), with the expected heterozygosity (He = 0.76) and observed heterozygosity (Ho = 0.83) indicating moderate-to-low genetic diversity. A molecular variance analysis (AMOVA) further revealed that 96% of the genetic variation originated within populations, with minimal inter-population differentiation (Fst = 0.04). Phylogenetic reconstruction using SSR markers demonstrated significant genealogical associations between the two cultivars, supporting the hypothesis that Thompson Seedless may have originated from a domesticated lineage of Munake. The selected SSR markers exhibited high discriminatory power (PIC = 0.92), enabling the precise differentiation of accessions with closely related genetic backgrounds. Whole-genome resequencing identified 20,074,046 and 69,214,080 high-quality SNPs in 100 Thompson Seedless and 141 Munake accessions, respectively. Core germplasm banks were subsequently established: the Thompson Seedless core collection (25 accessions) captured 94% of genetic variation, reflecting genetic homogenization driven by intensive clonal cultivation, while the Munake core collection (42 accessions) retained 95% of allelic diversity and resolved regional synonym issues through highly polymorphic SNP markers. A comparative analysis revealed that Munake maintains higher genetic diversity due to natural gene flow, whereas Thompson Seedless faces heightened risks of genetic erosion from prolonged asexual propagation. These findings provide a theoretical foundation and technical framework for precise conservation, varietal improvement, and sustainable utilization of grape germplasm resources in Xinjiang.

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.