Genetic diversity and genotypic stability in Prunus avium L. at the northern parts of species distribution range

Abstract

& Key message Large genetic variation was found in Prunus avium L. populations from the northern parts of the species distribution range. The ranking of genotypes in terms of growth was stable when tested at three trial sites within the northern parts of the species distribution range. & Context Peripheral populations especially those in the leading edge are isolated from rest of the areas in the species distribution range. This can make them less genetically diverse yet genetically distinct from the rest of the populations in the species distribution range. Evaluation of their genetic diversity is thus crucial in understanding the local adaptation potential of a species. & Aims We investigated the genetic diversity and genotype by environment interaction at the northern parts of the distribution range of P. avium. & Methods Quantitative genetic variation of growth, stem form, and spring phenology were assessed in progenies from 93 plus trees of P. avium selected from 43 locations at the north of the species distribution range in Sweden and tested at two Swedish sites and one Danish site. & Results We find large quantitative genetic variation in growth and phenology at the northern part of the distribution range of P. avium. Only a limited genotype by environment interaction was observed with no clear indication of local adaptation at the northern parts of the species distribution. & Conclusion We conclude that P. avium harbors a high level of genetic diversity at the north of its distribution range. Present patterns therefore reflect more likely the recent introduction of the species and dispersal dynamics rather than a long-term loss of diversity along South-North ecological clines during the Holocene. With no indications of genetic depletion in growth or phenology, the gene pool in the breeding program is considered suitable for the future propagation of the species in the tested area.

Genetic signature of the natural gene pool of Tilia cordata Mill. in Lithuania: Compound evolutionary and anthropogenic effects

“…In agreement with the earlier studies on Tilia sp. with the SSR markers (Barker, 2017;Erichsen et al, 2019;Lobo et al, 2018;Logan et al, 2015), we did not detect more than 2 alleles at all loci, confirming the diploidy of Tilia cordata. In our study, the observed heterozygosity estimates are not markedly affected by null alleles as shown by the MICROCHECKER tests and the high variation in the singe locus H o and F IS values among the populations.…”

“…with Erichsen et al (2019) study where no clear population structuring was found for Tilia cordata in Demark with the set of SSR markers. Based on the findings discussed above, this genetic structure is likely to be shaped by the balance between drift caused fragmentation and gene flow as well as local effects of urban escapes (Lobo et al, 2018). There also could be signs of adaptation to poor soils and relatively higher frost tolerance in the coldest region in Lithuaniathe northeastern highland.…”

“…The results from the few available microsatellite-based studies on Tilia cordata are diverse. Logan et al (2015) found no marked reduction of genetic diversity of Tilia cordata in the UK, located not far from the margin of the range, whereas Lobo et al (2018) reported possible genetic drift effects on Tilia cordata in Demark. Therefore, the situation with the genetic diversity of Tilia cordata may vary depending on the region.…”

“…In different parts of Europe, these autochthonous gene pools were subjected to diverse adaptive pressure, land-use history, urban development, and forest use intensity. This led to a marked regional variation in the genetic condition of Tilia cordata populations in Europe (Erichsen et al, 2019;Lobo et al, 2018;Logan et al, 2019).…”

“…Population fragmentation in Tilia cordata often leads to depleted diversity due to genetic drift, especially hazardous for entomophilous species with limited gene flow capacity (Erichsen et al, 2019;Lobo et al, 2018;Lowe et al, 2015). In addition to that, spreading from Tilia groups of likely low diversity in urban territories may further compromise the genetic stability of this newly expanding Tilia cordata populations.…”