Analysis of the variability of the Ornithogalum umbellatum L. 1753 (Hyacinthaceae) using molecular markers and morpho-anatomical characters

Abstract

<p>Predmet ovog istraživanja je varijabilnost taksona&nbsp; <em>Ornithogalum umbellatum</em>&nbsp; L. 1753. (Hyacinthaceae) na području Srbije i Mađarske. Ovaj najpoznatiji i najrasprostranjeniji predstavnik roda&nbsp;<em> Ornithogalum&nbsp;</em> L. izučava se dugi niz godina sa različitih aspekata: kao gajena ba&scaron;tenska vrsta i kao invazivni korov; kao otrovna biljka i potencijalno lekovita. Sa ekolo&scaron;kog aspekta&nbsp; ove biljke su značajne kao&nbsp; domaćini insektima polinatorima koji su vi&scaron;estruko i u različitim fazama razvića vezani za ove lukovičaste geofite. Veliki areal&nbsp; i prilagođenost različitim tipovima stani&scaron;ta uzrokuju značajnu varijabilnost, koja rezultuje taksonomskom konfuzijom.&nbsp; Jedan od razloga za&nbsp; istorijski prepoznatljive taksonomski i filogenetski nerazja&scaron;njene relacije&nbsp; su&nbsp; područja sa prirodnim stani&scaron;tima populacija&nbsp;<em> O.&nbsp; umbellatum</em>&nbsp; čijem izučavanju nije posvećeno dovoljno pažnje. Jedno od takvih je i ovde istraživano područje. Kako je u Flori Srbije kao podvrsta&nbsp;<em> O. umbellatum&nbsp;</em> opisan i&nbsp; <em>O. umbellatum&nbsp; subsp.&nbsp; divergens</em>&nbsp; (Boreau), analizama su obuhvaćene i populacije ovog taksona.</p><p>RAPD-PCR metodom ustanovljen je vi&scaron;i nivo genetičkog diverziteta između nego u<br />okviru populacija, bez jasnog geografskog trenda dispozicije ove varijabilnosti. Ovi su<br />rezultati očekivani za poliploidne taksone sa velikim udelom vegetativnog razmnožavanja u reproduktivnoj strategiji biljke, koji su pritom &scaron;iroko rasprostranjeni<br />a u istraživanom području predstavljeni uglavnom relativno udaljenim te izolovanim<br />populacijama.&nbsp; Determinacija genetičke struktuiranosti među ispitivanim&nbsp; genotipovima ukazala je na razdvajanje populacija dva taksona u dva klastera. Rezultate u saglasnosti sa ovim dala&nbsp; je i analiza parametara poprečnih preseka lista, skapusa i plodnika, a ustanovljeni su i diskriminativni anatomski karakteri koji su razdvojili populacije dva taksona. Izdvojeni su pojedini kvantitativni karakteri, kako anatomski tako i morfolo&scaron;ki, koji su&nbsp; najvi&scaron;e doprineli varijabilnosti na interpopulacionom nivou. Pokazana je velika raznolikost morfolo&scaron;kih karaktera i heterogenost populacija&nbsp;<em> O. umbellatum</em>, &scaron;to je u skladu sa podacima u postojećoj litaraturi. Poznato je i da&nbsp; habitus ovih&nbsp; biljaka&nbsp; veoma&nbsp; zavisi&nbsp; od&nbsp; uslova&nbsp; sredine,&nbsp; kao&nbsp; i&nbsp; stadijuma&nbsp; razvića&nbsp; biljke,&nbsp; dok&nbsp; na molekularne&nbsp; markere&nbsp; ovi&nbsp; faktori&nbsp; ne&nbsp; utiču.&nbsp; Sa&nbsp; druge&nbsp; strane,&nbsp; iako&nbsp; primenjena&nbsp; RAPD metoda&nbsp; nije&nbsp; dovoljna&nbsp; za&nbsp; determinaciju&nbsp; filogenetski&nbsp; blisko&nbsp; srodnih&nbsp; taksona&nbsp; poput&nbsp; ovih, pokazala&nbsp; se&nbsp; pouzdanom&nbsp; i&nbsp; efikasnom&nbsp; za&nbsp; ispitivanje&nbsp; diverziteta&nbsp; na&nbsp; populaciono-genetičkom&nbsp; nivou.&nbsp; Stoga&nbsp; je&nbsp; u&nbsp; cilju&nbsp; &scaron;to&nbsp; sveobuhvatnije&nbsp; procene&nbsp; stanja&nbsp; kori&scaron;ćena kombinacija&nbsp; različitih&nbsp; pristupa,&nbsp; koji&nbsp; su&nbsp; dali&nbsp; usagla&scaron;ene&nbsp; rezultate,&nbsp; istovremeno&nbsp; dajući uvid&nbsp; u&nbsp; nivo&nbsp; polimorfnosti&nbsp; i&nbsp; struktuiranosti&nbsp; populacija&nbsp; i&nbsp; ukazujući&nbsp; na&nbsp; jedinstvene&nbsp; oblike<br />varijabilnosti morfo-anatomskih karakteristika</p><p>Sa&nbsp; jedne&nbsp; strane&nbsp; ovo&nbsp; je&nbsp; važno&nbsp; zbog&nbsp; razja&scaron;njenja&nbsp; komplikovane&nbsp; taksonomije,&nbsp; a&nbsp; sa&nbsp; druge zbog&nbsp; značaja&nbsp; ovih&nbsp; biljaka&nbsp; sa&nbsp; aspekta&nbsp; potencijalne&nbsp; koristi&nbsp; odnosno&nbsp; &scaron;tete&nbsp; za&nbsp; čoveka,&nbsp; ali&nbsp; i iz&nbsp; ugla&nbsp; za&scaron;tite&nbsp; biodiverziteta.&nbsp; Uvid&nbsp; u&nbsp; nivo&nbsp; varijabilnosti&nbsp; populacija&nbsp; doprineće adekvatnim&nbsp; strategijama&nbsp; konzervacije&nbsp; i&nbsp; menadžmenta&nbsp; kako&nbsp; ovih&nbsp; biljnih&nbsp; vrsta,&nbsp; tako&nbsp; i insekatskih sa kojima su povezane.</p>

<p>Variability of&nbsp; <em>Ornithogalum umbellatum&nbsp;</em> L. 1753. (Hyacinthaceae) in&nbsp; Serbia and Hungary&nbsp; was analyzed in this research. This most famous and the most&nbsp; widespread taxon in genus <em>Ornithogalum</em> L. has been a research subject for many years for various reasons: as garden plant and invasive weed; for its toxic and pharmaceutical properties. From an ecological point of view those bulbous geophytes&nbsp; are the important host-plants for insect pollinators associated with them in different life stages.&nbsp; Large distribution area and adaptation to diverse habitat types result in significant variability of these plants which is followed by&nbsp; taxonomic confusion. Persisting taxonomic problems arise also from the fact that there are under-investigated regions with native populations of <em>O.</em>&nbsp;<em>umbellatum, </em>such as&nbsp; localities&nbsp; in Serbia and neighbouring countries. Since published floras of these countries&nbsp; include&nbsp; <em>O. umbellatum&nbsp;</em> subsp.&nbsp; <em>divergens</em> (Boreau), analyses involve populations of this taxon as&nbsp; well.</p><p>RAPD-PCR method revealed higher levels of genetic diversity among than within populations, without distinct geographical trend in the disposition of the variability. These results have been expected for polyploid taxa with high levels of vegetative reproduction, widespread and represented mostly with relatively distant and isolated populations in the given region. Genetic structure analyses have separated&nbsp; populations of the two investigated taxa into two clusters. Analyses of the anatomical characteristics of the leaf, scapus and ovary cross-sections have shown results in accordance with those. Discriminative characters which divided populations of the two&nbsp; taxa were determined. Distinctive quantitative characters, both anatomical and morphological, which have contributed the most to the interpopulation variability, were&nbsp; singled out. Great diversity of morphological characters and population heterogeneity&nbsp; of&nbsp; <em>O.&nbsp; umbellatum&nbsp;</em> has been&nbsp; shown, which&nbsp; was&nbsp; already described in literature dealing with the subject. Additionally, the high diversity is explained by the fact that habitus of those plants with very plastic phenotypes is influenced by environmental conditions and life stage of the plant. Those factors do not affect molecular markers; however techniques like RAPD-PCR could not be used independently for&nbsp; characterization&nbsp; of phylogenetically close taxa such as these. Nevertheless, RAPDs proved to be a reliable and efficient method suitable for distinguishing genetic differentiation on population level. Therefore, combination of different approaches was used in order to give comprehensive assessment of the situation. The results were consistent, revealing the levels of populations&rsquo;&nbsp; polymorphism and structure, as well as certain variations of morpho-anatomical features.</p><p>This is important in the light of complicated&nbsp; taxonomy clarification, and on the other hand from the aspect of potential value or harm of these plants to humans. In terms of&nbsp; biodiversity conservation, insight into population variability levels might contribute to adequate management strategies for both plants and insects related to them.</p>