Polyploid origin, genetic diversity and population structure in the tetraploid sea lavender Limonium narbonense Miller (Plumbaginaceae) from eastern Spain

Abstract

Limonium narbonense Miller is a fertile tetraploid species with a sporophytic self-incompatibility system. This sea lavender is found in coastal salt marshes which have been under intense human pressure during the past decades resulting in significant habitat fragmentation. Eleven microsatellite loci specifically designed for this species were amplified in 135 individuals from five populations. These markers were used to investigate the polyploid nature, the levels of genetic diversity and population structure in this species. L. narbonense showed high levels of genetic diversity (A = 7.82, P = 100% H (T) = 0.446), consistent with its likely autotetraploid origin revealed in this study and obligate outcrossing breeding system. Inbreeding (F (IS)) values were low in the three southern populations (mean F (IS) = 0.062), and higher in the northern populations (mean F (IS) = 0.184). Bayesian analysis of population structure revealed that populations could be grouped into two genetic clusters, one including three southern populations and the other the two northernmost ones. Individuals from the two northernmost populations showed higher admixture of the two genetic clusters than individuals from the three southern ones. A thorough analysis of microsatellite electrophoretic patterns suggests an autotetraploid origin for L. narbonense. The genetic structure revealed in this study is attributed to a recent migration from the southern area. This result suggests a net gene flow from the south to the north, likely facilitated by migratory movements of birds visiting the temporary flooded ponds occupied by L. narbonense.

Assessment of genetic diversity and population structure of Tunisian populations of Brachypodium hybridum by SSR markers

“…This finding agrees with the expected results for predominantly selfing species (Vanden Broeck et al, 2014), However,the level of genetic diversity reported in our study was found to be slightly higher than that detected by Vogel et al (2009) andFiliz et al (2009b) in a large Turkish collection of B. distachyon by using SSR and SRAP markers, respectively.Conversely, a relatively low level of genetic diversity was revealed by Hammami et al (2012) in a relatively small Spanish collection of thecomplex of species B. distachyon, B. stacei and B. hybridum (7, 4 and 12 accessions,respectively) by using allozymes, and by Jaroszowicz et al (2012) in a collection of 18Eurasian B. distachyon accessions by using RAPD markers. The high genetic diversityobserved in our study agrees with the expectations for polyploid taxa since it has beendemonstrated that the polyploid species typically display a great genetic diversity (Palop-Esteban et al, 2011).Moreover, our results showed that the observed heterozygosity across the studied populations was lower about three times than the expected heterozygosity (31% vs 79%), whichconfirms that B.…”

Conservation genetics of Magnolia acuminata, an endangered species in Canada: Can genetic diversity be maintained in fragmented, peripheral populations?

“…Population genetic analyses of polyploid data can be done following either a genotypebased (e.g. Palop-Esteban et al 2011) or phenotype-based (e.g. Obbard et al 2006;Vinson et al 2015) approach and, because information can be lost using either method, and each type of analysis has its own set of assumptions, we compared the results of both approaches (following Kirk et al 2011) for many of our analyses.…”

Genetic Diversity and Origins of the Homoploid-Type Hybrid Phytophthora ×alni

“…Thus, better knowledge of the processes that give rise to hybrid taxa is an important question in the evolutionary biology of emerging pathogens. Understanding the mechanisms that lead to speciation and to the establishment, spread, and evolution of hybrid taxa requires investigation of the identity and genetic variability of parental species and of the directionality and recurrence of the hybridization events (9,10).…”