Although a major drawback of ISSRs is its inability to detect heterozygotes, this marker is recognized as a valuable and affordable method for the evaluation of diversity and genetic structure of a wide range plants, including Crassulaceae species. Among these markers, ISSR is a multi-dominant locus marker that generally produces multiple DNA fragments throughout the genome of any species, presents Mendelian inheritance, reproducibility, is highly polymorphic and low cost. Ĭurrently, there are various methods of DNA-based markers for the genetic analysis of plant populations, the most common being amplified-fragment length polymorphism (AFLP), inter-simple sequence repeats (ISSRs), microsatellites (SSR), and single nucleotide polymorphisms (SNPs) each varies in polymorphism quantification, repeatability, resolution power and analysis cost. Moreover, genetic studies are essential when the evaluation of extinction risk is difficult to assess from ecological and demographic data alone. Thus, these studies can significantly strengthen strategies for population management, determine critical populations for conservation, and reduce species’ risk of extinction. Genetic studies of rare plants allow us to describe patterns of genetic diversity, population structure, and effective population size.
#Geographic distance matrix in genodive series
Based on our results, we propose to reclassify the conservation status of the species in danger of extinction, hence a series of conservation strategies are provided to prevent its disappearance.Įcological and genetic studies are essential to implement conservation plans, especially in endangered, rare and endemic plant species, in order to face of the global crisis of biodiversity loss. Genetic parameters are negatively affected by the loss of individuals and the local extinction of populations. Additionally, a genetic structure of the populations was found with low gene flow (Nm = 0.92). The average results indicated moderate levels of genetic diversity (number of alleles = 89.7 ± 3.9, expected heterozygosity = 0.212 ± 0.0, and percentage of polymorphic loci = 56.1 ± 3.9), parameters that decreased significantly when simulations were performed in P. Additionally, we carried out two simulations to explore how the loss of individuals or the local populations extinction affect the genetics parameters of the species. Twelve dominant ISSR markers were used to describe the genetic diversity of all known populations. This work analyzes the diversity and genetic structure of Pachyphytum cesium (Crassulaceae) to change the conservation status and propose conservation strategies. Pachyphytum caesium is an endemic species with extremely small populations in central Mexico. Genetic studies in rare species are important to determine their patterns of genetic diversity among populations and implement conservation plans aimed to reduce extinction risks.