1. Evolution of a hybrid zone of willows (Salix L.) in the Alps analysed by RAD-seq and morphometricsPia Marinček, 2022, magistrsko delo Povzetek: Natural hybridization of plants can result in many outcomes with several evolutionary consequences, such as hybrid speciation and introgression. Natural hybrid zones can arise as a result of fluctuating climate during the exchange of glacial and interglacial periods, where species retract and expand their territories, resulting in secondary contacts. On mountain ranges, such as the European Alps, hybrid zones of alpine species are frequently formed where different lineages meet. Willows are a large genus of woody plants with an immense capability of interspecific crossing. About 33 species of this genus inhabit the Alps, where intermediate phenotypes were frequently observed and proclaimed as hybrids, but rarely examined in detail. One of the reasons was a lack of informative molecular markers and suitable analytical tools to analyse this highly diverse and convergent genus. With the development of the RAD-seq technology, several questions regarding willow phylogeny and hybridization could be answered. In this study, a putative hybrid zone of two sister species, S. foetida and S. waldsteiniana, was investigated to study the genomic structure of populations within and outside their contact zone, to find evidence for hybrid speciation or introgression, and to analyse if morphological phenotypes are reflected by their genotypes. Individuals of the two species were sampled across their distribution range in the Alps and examined with the use of RADseq data and morphometric analyses. The results showed that a hybrid zone between the two species was established within the range of their contact zone. Patterns of genetic admixture in homoploid hybrids indicated introgression with asymmetric backcrossing to one of the parental species. Morphometric characteristics of hybrids supported the molecular data and showed intermediacy with a bias towards S. waldsteiniana. Only one potentially divergent hybrid lineage was observed, hinting to a possibility of localised hybrid speciation events.
Ključne besede: alpine plants, hybridization, morphometry, RAD sequencing, master thesis
Objavljeno v DiRROS: 17.01.2025; Ogledov: 306; Prenosov: 100
 Celotno besedilo (4,66 MB) |
2. Using genomic information for management planning of an endangered perennial, Viola uliginosaKyung Min Lee, Pertti Ranta, Jarmo Saarikivi, Lado Kutnar, Branko Vreš, Maxim Dzhus, Marko Mutanen, Laura Kvist, 2020, izvirni znanstveni članek Povzetek: Species occupying habitats subjected to frequent natural and/or anthropogenic changes are a challenge for conservation management. We studied one such species, Viola uliginosa, an endangered perennial wetland species typically inhabiting sporadi-cally flooded meadows alongside rivers/lakes. In order to estimate genomic diversity, population structure, and history, we sampled five sites in Finland, three in Estonia, and one each in Slovenia, Belarus, and Poland using genomic SNP data with double-digest restriction site-associated DNA sequencing (ddRAD-seq). We found mono-phyletic populations, high levels of inbreeding (mean population FSNP = 0.407-0.945), low effective population sizes (Ne = 0.8-50.9), indications of past demographic ex-pansion, and rare long-distance dispersal. Our results are important in implementing conservation strategies for V. uliginosa, which should include founding of seed banks, ex situ cultivations, and reintroductions with individuals of proper origin, combined with continuous population monitoring and habitat management.
Ključne besede: nature conservation, demography, genomic diversity, population genomics, RAD sequencing, Viola
Objavljeno v DiRROS: 20.01.2022; Ogledov: 1570; Prenosov: 1203
Celotno besedilo (1,49 MB)
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