Genetic diversity and population structure in the Brazilian Cattleya labiata (Orchidaceae) using RAPD and ISSR markers

Abstract

Brazilian orchids are currently threatened with extinction due to habitat loss and, because of their high ornamental value, intense collecting pressure. Genetic diversity can play a key role in the survival of endangered orchid species. Here we provide the first data on genetic diversity and structure of wild populations in the genus Cattleya, in particular C. labiata, using random amplified polymorphic DNA (RAPD) and intersimple sequence repeat (ISSR) markers. We studied 130 individuals, 117 belonging to Cattleya labiata and 13 from 10 other species in the same genus. Data generated from 12 ISSR and 12 RAPD primers were used to determine genetic variability via a model-based Bayesian procedure (Structure) and molecular variance analysis. In addition, Shannon index, genetic diversity and Jaccard coefficients were also estimated. The marker data indicated that C. labiata has a high level of polymorphism, and five reconstructed populations were identified by Structure. The unweighted pair group method with arithmetic mean dendrogram did not group the samples by origin, which was also confirmed by Bayesian analysis, demonstrating the complex genetic structure of C. labiata. Other Cattleya species showed no relationship with any C. labiata sample. This genetic characterization of Cattleya from northeast Brazil contributes to knowledge of the genetic structure of the species and can be used to define strategies for conservation and breeding programmes.

Massive Extraction of the OrchidLaelia speciosa(HBK) Schltr. for Trading in Local Markets Affect Its Population Genetic Structure in a Fragmented Landscape in Central Mexico

“…The majority of population genetic studies have been focused on both epiphytic and terrestrial orchids and was mainly based on isozymes (Á vila-Dı´az & Oyama, 2007;Borba, Felix, Solferini, & Semir, 2001;Murren, 2003;Trapnell, Hamrick, & Nason, 2004) and microsatellites (Da Cruz, Selbach-Schnadelbach, Lambert, Ribeiro, & Borba, 2011;Mun˜oz, Warner, & Albertazzi, 2010;Pinheiro et al, 2012;Stone, Crystal, Devlin, Downer, & Cameron, 2012;Swarts, Sinclair, Krauss, & Dixon, 2009;Vargas, Parra-Tabla, Feinsinger, & Leirana-Alcocer, 2006). Despite the molecular marker used, the few studies in orchids indicated that epiphytes enjoy some of the dispersal advantages of trees (e.g., greater potential for gene flow derived from longer-distance dispersal of pollen and seeds; Borba et al, 2001;Flores-Palacios & Garcı´a-Franco, 2003;, which may attenuate the genetic impacts of habitat fragmentation.…”

Molecular characterization of bromeliads from northeast Brazil

“…Previous studies have reported that DNA fingerprinting techniques, in combination with ISSR and RAPD, are usefulfor genotypediscrimination and for genetic similarity analysis (Fernández et al, 2002;Pinheiro et al, 2012).…”

Diversity and genetic structure of jenipapo (Genipa americana L.) Brazilian accessions

“…For ISSR, 12 primers from Operon were used (Pinheiro et al, 2012) to screen for polymorphisms (Table 2). Polymerase chain reaction (PCR) amplifications were performed using a PTC-100 thermocycler, with reactions consisting of 5-min initial denaturation at 95 ºC, followed by 45 cycles of denaturation at 94 ºC for 1 min, primer annealing at 52 ºC for 1 min and extension at 72 ºC for 45 s, and one final extension step at 72 ºC for 10 min.…”