Genetic diversity and taxonomy within the genus Rhinanthus
Date
2015-02-03
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Meie planeedi bioloogiline mitmekesisus kahaneb kiiresti. Tänaseks on teada, et liikide ellujäämiseks on oluline geneetiline varieeruvus. Geneetilise diversiteedi uurimine võib aidata lahendata keerukate liigikomplekside taksonoomiat ning annab infot tänapäeva liigirikkuse, liikide mineviku ja evolutsiooni kohta. Lisaks sellele mõjutab geneetilist mitmekesisust ka taimede paljunemisviis ning populatsioonide suurused. Seega on oluline hinnata liikide geneetilist mitmekesisust. Käesolevad doktoritöös uurisin isoensüümide ja mikrosatelliitidega seitsme liigi geneetilist varieeruvust perekonnast Rhinanthus. Uuritud liigid kuulusid kolme erinevasse sektsiooni: Eesti endeem R. osiliensis, R. rumelicus, R. wagneri, R. angustifolius, R. alectorolophus sektsiooni Cleistolemus, R. minor sektsiooni Rhinanthus ning Bulgaaria endeem R. javorkae sektsiooni Anoectolemi. Lisaks sellele võrdlesime esmakordselt geneetiliselt Rootsi saarelt Gotlandilt leitud ebaselget robirohu taksonit morfoloogiliselt sarnase Eesti endeemiga R. osiliensis. Tulemused näitasid laialdast sugulusristumist enamuses uuritud populatsioonidest hoolimata liigilisest kuuluvusest. Endeemidel (R. osiliensis ja R. javorkae) ning kitsa levikuga Gotlandilt leitud ebaselgel taksonil on madalam geneetiline mitmekesisus võrreldes laialt levinud liikidega (R. rumelicus, R. wagneri, R. angustifolius). Siiski, madal geneetiline mitmekesisus leiti samuti laialt levinud liigil R. minor, mis ilmselt on tingitud liigi õie morfoloogiast. Geneetiliselt eristusid hästi eraldi sektsioonidesse kuuluvad R. minor ja bulgaaria endeem R. javorkae. Uuritud sektsiooni Cleistomus liigid on geneetiliselt teineteisele sarnased välja arvatud R. alectorolophus, mis eristus märkimisväärselt teistest sama sektsiooni liikides. Seega on sektsiooni Cleistolemus monofüleetilisus küsitav. Lõpetuseks näitasid tulemused, et Rootsist Gotlandi saarelt leitud robirohi on geneetiliselt märkimisväärselt erinev morfoloogiliselt sarnase Saaremaa robirohuga R. osiliensis ning tegemist ei ole ühe liigiga. Minu doktoritöö näitab mlekulaargeneetiliste uuringute tähtsust aitamaks selgitada keerulisi liikidevahelisi suhteid, hinnata populatsioonide jõulisust.
Biological diversity is rapidly decreasing. Evaluation of genetic diversity and assessment of genetic differentiation are essential for estimate boundaries between species. Different aspects of genetic diversity provide valuable information about the species delimitation, relationships and species boundaries. Genetic diversity and differentiation levels of seven Rhinanthus species from three different sections and one unclear taxon were studied in this thesis Estonian endem R. osiliensis, R. rumelicus, R. wagneri, R. angustifolius and R. alectorolophus belonging to section Cleistolemus, R. minor to section Rhinanthus and Bulgarian endem R. javorkae to section Anoectolemi. In addition, taxonomically unclear individuals found from Sweden were studied and compared with R. osiliensis, R. angustifolius and R. minor from Estonia. Two different molecular techniques - allozymes and microsatellites - were used for analyses. We found high level of non-random mating and inbreeding in most of the studied populations. Low genetic diversity was found in unknown Rhinanthus sp., endemics R. osiliensis and R. javorkae with restricted geographic range. Widespread R. minor showed also low level of genetic variation and high inbreeding mode due to flower morphology. Our results of genetic differentiation were in concordance with previous taxonomy where R. minor and R. javokae belong to two different sections were well differentiated from other studied species. Surprisingly, R. alectorolophus that belongs to section Cleistolemus together with R. osiliensis, R. rumelicus, R. wagneri and R. angustifolius was strongly differentiated from those species and monophyly of this section is questionable. Low genetic differentiation of R. osiliensis, R. rumelicus, R. wagneri and R. angustifolius shows their close affinity and weak genetic structure of section Cleistolemus. Finnaly, we clearly showed that the unknown Rhinantus sp. found from Gotland, while morphologically similar to R. osiliensis, does not belong to the same taxon. Both R. osiliensis and Rhinanthus sp. are genetically more close to R. angustifolius. We suggest that these two cryptic species originated from two independent island colonization events and may be even from different refugia. Further genetic comparison between unknown Rhinanthus sp. and local Rhinanthus species from Gotland is necessary to determine the species status and to check for possible alternative hypotheses about the origin of this unclear taxon.
Biological diversity is rapidly decreasing. Evaluation of genetic diversity and assessment of genetic differentiation are essential for estimate boundaries between species. Different aspects of genetic diversity provide valuable information about the species delimitation, relationships and species boundaries. Genetic diversity and differentiation levels of seven Rhinanthus species from three different sections and one unclear taxon were studied in this thesis Estonian endem R. osiliensis, R. rumelicus, R. wagneri, R. angustifolius and R. alectorolophus belonging to section Cleistolemus, R. minor to section Rhinanthus and Bulgarian endem R. javorkae to section Anoectolemi. In addition, taxonomically unclear individuals found from Sweden were studied and compared with R. osiliensis, R. angustifolius and R. minor from Estonia. Two different molecular techniques - allozymes and microsatellites - were used for analyses. We found high level of non-random mating and inbreeding in most of the studied populations. Low genetic diversity was found in unknown Rhinanthus sp., endemics R. osiliensis and R. javorkae with restricted geographic range. Widespread R. minor showed also low level of genetic variation and high inbreeding mode due to flower morphology. Our results of genetic differentiation were in concordance with previous taxonomy where R. minor and R. javokae belong to two different sections were well differentiated from other studied species. Surprisingly, R. alectorolophus that belongs to section Cleistolemus together with R. osiliensis, R. rumelicus, R. wagneri and R. angustifolius was strongly differentiated from those species and monophyly of this section is questionable. Low genetic differentiation of R. osiliensis, R. rumelicus, R. wagneri and R. angustifolius shows their close affinity and weak genetic structure of section Cleistolemus. Finnaly, we clearly showed that the unknown Rhinantus sp. found from Gotland, while morphologically similar to R. osiliensis, does not belong to the same taxon. Both R. osiliensis and Rhinanthus sp. are genetically more close to R. angustifolius. We suggest that these two cryptic species originated from two independent island colonization events and may be even from different refugia. Further genetic comparison between unknown Rhinanthus sp. and local Rhinanthus species from Gotland is necessary to determine the species status and to check for possible alternative hypotheses about the origin of this unclear taxon.
Description
Väitekirja elektrooniline versioon ei sisalda publikatsioone.
Keywords
saaremaa robirohi, geneetiline muutlikkus, taksonoomia, Saaremaa yellow rattle, genetic diversity, taxonomy