Procena varijabilnosti prirodnih populacija crne topole (Populus nigra L.) na području Vojvodine primenom genetičkih markera

Abstract

Crna topola (Populus nigra L.) predstavlja jednu od najznačajnijih, ali potpuno marginalizovanih vrsta šumskog drveća aluvijalnih staništa u Evropi. Poslednjih decenija suočena je s ozbiljnim pretnjama po pitanju opstanka, pre svega zbog gubitka svojih staništa i nemogućnosti prirodne obnove, te se stoga ubraja u najugroženije drvenaste vrste Evrope. Sprovedena istraživanja imala su za cilj upoznavanje genetičkog diverziteta unutar i između četiri prirodne populacije crne topole, koje se nalaze uz tokove tri najveće reke u Vojvodini: Dunava (gornji i donji tok), Save i Tise. Odabrane populacije predstavljaju ostatke nekadašnjih prirodnih populacija u kojima je još uvek prisutan određeni genofond ove vrste, sveden na pretežno stara stabla, uz nedostatak prirodnog obnavljanja. Genetička varijabilnost unutar i između analiziranih populacija procenjena je primenom tri tipa genetičkih markera: morfoloških, anatomskih i molekularnih (SSR). Analize na nivou morfoloških markera obuhvatile su devet osnovnih (dužina i širina lista, dužina peteljke, ugao između prvog nerva i horizontale, širina lista na 1cm od samog vrha lista, rastojanje između osnove lista i najšireg dela lista, dužina celog lista, broj nerava sa leve strane lista, broj nerava sa desne strane lista) i tri izvedene karakteristike listova (odnosi širine i dužine lista, širine vrha i dužine lista, udaljenost baze do najšireg dela lista i dužina lista). Primenom anatomskih markera analizirano je pet osnovnih (gustina stoma, dimenzije stoma – dužina i širina ćelija zatvaračica i stomatalnog otvora) i tri izvedene karakteristike stoma lista (koeficijent oblika stoma, potencijalni indeks propustljivosti stoma, odnos gustine stoma lica i naličja), dok je molekularnim markerima urađena analiza dvanaest mikrosatelitnih markera (SSR) u cilju procene neutralne varijabilnosti. Dobijeni rezultati ukazuju na značajnu varijabilnost unutarpopulacija i malu varijabilnost međupopulacijama. AMOVA je razdvojila nivoe varijabilnosti kako bi se uvideo koji je njihov udeo u sveukupnoj varijabilnosti, pri čemu je varijabilnost između istraživnih populacija bila svega 4.31%...

Black poplar (Populus nigra L.) is one of the most important, but nonetheless most marginalized forest tree species in alluvial habitats of Europe. In recent decades it has faced serious threats pertaining to its survival, primarily due to the loss of the natural habitat and the lack of natural regeneration. Therefore it is considered to be one of the most endangered tree species in Europe. The aim of the conducted research was to explore the genetic diversity of within and between black poplar natural populations, growing in the area between the three largest rivers in the region of Vojvodina: the Danube (the upper and lower stream), Sava and Tisa. Selected populations are remnants of the former natural riparian populations which still show presence of aspecific gene pool of the species, primarily with old trees and withthe lack of natural regeneration. Genetic variability within populations and between the studied populations was estimated by using three types of genetic markers: morphological, anatomical and molecular (SSR). The analysis with morphological markers included the nine basic (leaf length and width, stem length, the angle between the first vein and horizontal, leaf width at 1cm from the top of the leaf, the distance between the base and the widest part of the leaf, the entire length of the leaf, the number of veins at the left side of leaf, the number of veins at the right side of the leaf) and three derived characteristics of leaves (ratio of leaf width and length, peak width and length of the leaf, the distance to the widest part of the base and leaf length). By using anatomical markers five basic(stomatal density, stomatal dimensions - length and width of guard cells and stomatal aperture) and three derived features of leaf stomata (stomatal shape coefficient, potential conductance index, the ratio of adaxial and abaxial stomata density) were analyzed, while the molecular marker analysis was performed with twelve microsatellite markers (SSR) in order to estimate the neutral variability. The results indicate significant variability within single populations and low variability between different populations. AMOVA splits levels of variability to provide insight into their share in the overall variability, where the variation between studied populations was only 4.31%...