RAPD Variation Within and Among Natural Populations of Trembling Aspen (Populus tremuloides Michx.) From Alberta

Abstract

This article described the population structure of trembling aspen (Populus tremuloides Michx.) in Alberta, a dioecious tree with continuous and wide distribution, and with a primary mode of reproduction through suckering. We studied random amplified polymorphic DNA (RAPD) variation in 249 trees from eight natural populations. Trees within a population were a minimum of 200 m apart to decrease the risk of sampling ramets of a single ortet. Of a total of 28 amplified RAPD products (bands) from five random oligonucleotide primers, the frequencies at seven (25%) were heterogeneous across populations and the percentage of polymorphism averaged 90.2 per population. Estimates of Shannon's phenotypic diversity index ranged between 0.58 and 0.69 among populations, averaging 0.65. There were 246 multiband phenotypes among the 249 trees; three were each shared by two trees from different populations and the remaining 243 were unique. Thus, trees within populations probably were different clones. Analysis of molecular variance partitioned the RAPD variation into the among- and within-population components. The within-population component accounted for 97.4% of the variation and was significantly different from zero at the 2% level of probability. The among-population component, although accounting for only 2.6% of the variation, was significantly different from zero at the 1% level of probability. Pairwise tests for the homogeneity of the RAPD variance between populations suggested significant divergences among 18 of the 28 (64%) population pairs.

Genetic structure of natural Eugenia dysenterica DC (Myrtaceae) populations in northeastern Goiás, Brazil, accessed by morphological traits and RAPD markers

“…According to these authors, the presence of specific bands at each sampling site may be the result of the separate evolution of the populations by restriction to the gene flow. Lower levels of differentiation among populations were obtained by Yeh et al (1995) in natural populations of the Populus tremuloides Michx species. The differentiation among populations, although small (2.6%), was highly significant.…”

“…This value is similar to that obtained by Gillies et al (1997) who analyzed Cedrela odorata populations in Costa Rica, with the same type of marker. High levels of total variance are also reported for temperate climate species (Yeh et al, 1995;Liao and Hsiao, 1998). Although most of the genetic variance is found within populations there is a highly significant quantity among populations (about 8% of total variability), indicating gene flow restriction among populations.…”

“…These techniques have been applied to wild species to answer specific questions, mainly regarding the crossing system (Hayward and Hamilton, 1997). Some studies based on microsatellites have been employed in the study of natural populations (Collevatti et al, 2001;Zucchi et al, 2003) but most of the studies are performed with RAPD markers in plants (Chalmers et al, 1992;Wolf andRijn, 1993, Bucci andMenozzi, 1995;Yeh et al, 1995;Maguire and Sedgley 1997;Gillies et al, 1997, Palácios andGonzález-Candelas, 1997;Gallois et al, 1998, Cattan-Toupance et al, 1998, Skabo et al, 1998, and in other organisms (Peever andMilgroom, 1994, Lou et al, 1998).…”

Population Genetic Survey of Populus cathayana Originating From Southeastern Qinghai-Tibetan Plateau of China Based on SSR Markers

“…During the long evolutionary process, changes in distributions and adaptations to the harsh conditions have taken place (YU et al, 2003;WANG et al, 2005). Previous studies have showed that geographical isolation, complex and variable climate conditions are the main factors contributing to the genetic composition of plant populations (GEHRING and LINHART, 1992;STRAUS et al, 1992;YEH et al, 1995). The populations of P. cathayana occur in disjunctive mountain areas with a large geographic range of vertical altitude.…”

Genetic diversity among populations of the xerophytic tree species Balanites aegyptiaca and its morpho-physiological responses to water deficiency

“…Genetic variations among these sources may have been achieved by outcrossing and also by the spread of the seeds through various geographic areas. The high genetic diversity within populations with low diversity among countries has also been reported in many outcrossing woody plants species such as Uapaca kirkiana (Mwase et al, 2006) and Populus tremuloides (Yeh et al, 1995). This is a 1st report based on AFLP fingerprint to investigate the genetic diversity among different provenances of B. aegyptiaca collected from different countries.…”