Genetic diversity of the endangered and narrow endemic Piperia yadonii (Orchidaceae) assessed with ISSR polymorphisms

Abstract

Highly endangered plants that are also narrow endemics are generally found to be genetically depauperate and thus are exceedingly susceptible to ecological and anthropological threats that can lead to their extinction. Piperia yadonii is restricted to a single California county within a biodiversity hotspot. We used nine primers to generate intersimple sequence repeat (ISSR) data to assess its genetic diversity and structure. Within each population, 99% of the loci were polymorphic, expected heterozygosity was low, and a majority of the loci were shared with few other populations. Forty percent of the total variation could be attributed to population differentiation while the rest (60%) resides within populations, and the genetic distances between populations were independent of the corresponding geographical distances. High divergence among populations is likely due to fragmentation and limited gene flow. Each population contains several private loci, and ideally, each should be protected to preserve the overall diversity of the species. Because P. yadonii currently retains a modest amount of genetic variation among individuals within populations, preserving and expanding the habitat at each site to allow natural expansion of populations would be additional strategies for its conservation before populations become too small to persist naturally.

Assessment of genetic diversity among four orchids based on ddRAD sequencing data for conservation purposes

“…Genetic diversity helps to understand the evolutionary consequences in order to get idea about the genetic drift, mutational process and direction of gene-flow and divergence phenomena in the populations (Dressler 1993;Chase et al 2005;George et al 2009). Orchids contain high level of genomic complexity, because it carries wide range of variation in DNA content.…”

Molecular Study on Endemic Cattleya Species from Brazilian Flora

“…This polymorphism is justified by the use of the three species and the different accessions of each. High levels of polymorphism were found in other orchids genus such as Dendrobium (Wang, 2009), Piperia (George, 2009) and Cymbidium .…”

“…The ISSR markers were useful in phylogenetic relations determination studies among species and subjects within the same species in orchids such as Dendrobium (Wang et al, 2009), Piperiayadonii (George et al, 2009), Cymbidiumspp , Cattleyaspp and Brassavolatuberculata (Fajardo et al, 2014). In this study the ISSR markers were used for the purpose of comparing the polymorphic fragment pattern in commercialized plants named Cattleya guttata, C. tigrina e C. leopoldii, aiming to find variations in the germplasm.…”

Analysis of genetic diversity of Laeliinae (Orchidaceae) in the State of Sergipe using ISSR markers

“…Studies on patterns of genetic diversity within populations and the structure between populations may help to infer evolutionary mechanisms, such as genetic drift, selection, and mutation. Furthermore, the spatial genetic structure may serve as an indicator of the extent of gene flow and population divergence (George et al, 2009).…”