Ammopiptanthus possesses ancestral traits and, as a tertiary relict, is one of the surviving remnants of the ancient Mediterranean retreat and climate drought. It is also the only genus of super xerophytic, evergreen, broad-leaved shrubs. Ammopiptanthus nanus, one of the two species in this genus, is predominantly found in extremely arid and frigid environments, and is increasingly threatened with extinction. Study of the species’ genetic diversity is thus beneficial for its survival and the efficacy of ex situ conservation efforts. Based on transcriptome data, 15 pairs of effective EST-SSR were screened to evaluate A. nanus genetic diversity. In all, 87 samples from three populations were evaluated, the results of which show that ex situ conservation in the Wuqia region needs to be supplemented. Conservation and breeding of individual A. nanus offspring should be strengthened in the future to ensure their progeny continue to exhibit high genetic diversity and variation.
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.
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.
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.
Saussurea involucrata is a rare perennial herb endemic to the alpine zone of the Tianshan Mountains, possessing significant medicinal value yet facing severe threats from overharvesting and habitat fragmentation. The core distribution area and recognized genetic differentiation center of this species are located in the Bayinbuluke region of the Western Tianshan Mountains. In contrast, the genetic distinctiveness and conservation status of populations in the Eastern Tianshan Mountains have remained unclear. To clarify the genetic relationships, we conducted an integrated analysis using nuclear microsatellite (SSR) markers as well as chloroplast (cpDNA) and nuclear ribosomal DNA (nrDNA) sequences on 16 populations (5 from the Eastern Tianshan Mountains and 11 from the Bayinbuluke region). The results showed that the Eastern Tianshan Mountains populations exhibited higher genetic diversity (mean He = 0.5568). Bayesian clustering and principal coordinate analysis (PCoA) clearly separated all populations into two genetic groups corresponding to the two geographical regions. Notably, private haplotypes (cpDNA H1 and nrDNA H7) were identified exclusively in the Eastern Tianshan populations, and no recent genetic bottleneck was detected, indicating historical demographic stability. These findings demonstrate significant genetic differentiation and a unique evolutionary trajectory in the Eastern Tianshan Mountains populations, likely resulting from long-term geographical isolation and local adaptation to arid environments. Therefore, we propose that these populations be managed as an independent Management Unit (MU) to preserve their unique genetic legacy. This study provides critical genetic evidence for refining conservation strategies and promoting the sustainable use of this endangered species, while the established molecular marker system also offers a reliable framework for its geographical traceability.
Ammopiptanthus nanus (Fabaceae), a nationally protected endangered evergreen shrub endemic to Central Asian deserts, is severely threatened by habitat fragmentation. To conserve its genetic resources, multiple ex situ populations have been established across China. We evaluated conservation efficacy under distinct management strategies across four ex situ populations (n = 114), including a near-site protected area (J), a Forestry and Grassland Administration–managed zone (L), Tazhong Botanical Garden (T), and the Forestry Academy of Sciences (K), using integrated molecular markers: expressed sequence tag–simple sequence repeats (EST-SSRs), chloroplast DNA fragments ( psbA–trnH , trnL–trnF , trnS–trnG ), and nuclear ribosomal ITS (ITS1/ITS4) sequences. The results reveal significant strategy-dependent divergence in genetic conservation efficiency, primarily driven by founder genetic composition and reproductive management protocols. Strategy (J) retained moderate chloroplast diversity but exhibited reduced nuclear diversity and high inbreeding. Strategy (L) maintained moderate nuclear diversity yet limited chloroplast variation. Strategy (T) showed the highest nuclear diversity but minimal maternal lineage preservation. Strategy (K) preserved unique maternal haplotypes and phylogenetic distinctiveness despite constrained nuclear diversity. Critically, all populations displayed high inbreeding coefficients (F > 0.404), indicating genetic bottlenecks and restricted gene flow. To ensure long-term viability, we recommend: (1) diversifying genetic foundations through the introduction of founders from multiple wild sources and expansion of population sizes to mitigate drift; (2) enhancing gene flow via periodic interpopulation transplants and facilitated distant cross-pollination, integrated with long-term monitoring of nuclear and cytoplasmic diversity.