High genetic diversity promotes a common-garden trial of Quercus robur as a potential seed source

The process of adaptation in forest trees might be facilitated if seeds resulting from crossings among different provenances are used for plantation establishment. This can be accomplished if seeds from existing common-garden trials become available. This paper aims to characterize genetic diversity of a provenance/family common-garden trial of Quercus robur which is considered a possible source of highly diverse seed lots. Provenance/family common-garden trial of Quercus robur located in Oleszyce, Poland, consisting of 8 to 19 families of six Polish provenances was chosen for the study. With the aid of 16 nuclear microsatellite markers, 1812 trees growing in the trial were genotyped. Standard population genetic parameters were calculated, and genetic variation and inbreeding were compared among provenances. Expected heterozygosity and particularly allelic richness appeared to be high, reaching on average 0.847 and 23.5, respectively. We found no signatures of inbreeding (FIS=0.006) and low, although statistically significant, level of genetic differentiation among provenances (FST=0.016). On the other hand, we found high allelic differentiation (AST=0.137) between provenances, though uneven contribution of each provenance to the total allelic richness was noted. Effective population sizes estimated for each provenance based on linkage disequilibrium were highly correlated with the number of families within provenances. We conclude that the studied common-garden trial possesses high genetic diversity and possible mating among different provenances may promote further heterosis effects. Thus the trial may be used in the future as an experimental source of highly diverse seed lots much needed in the context of climate change

Data from: Beech roots are simultaneously colonized by multiple genets of the ectomycorrhizal fungus Laccaria amethystina clustered in two genetic groups

In this study we characterize and compare the genetic structure of aboveground and belowground populations of the ectomycorrhizal fungus Laccaria amethystina in an unmanaged mixed beech forest. Fruiting bodies and mycorrhizas of L. amethystina were mapped and collected in four plots in the Świętokrzyskie Mountains (Poland). A total of 563 fruiting bodies and 394 mycorrhizas were successfully genotyped using the rDNA IGS1 (intergenic spacer) and seven SSR (simple sequence repeat) markers. We identified two different genetic clusters of L. amethystina in all of the plots, suggesting that a process of sympatric isolation may be occurring at a local scale. The proportion of individuals belonging to each cluster was similar among plots aboveground while it significantly differed belowground. Predominance of a given cluster could be explained by distinct host preferences or by priority effects and competition among genets. Both aboveground and belowground populations consisted of many intermingling small genets. Consequently, host trees were simultaneously colonized by many L. amethystina genets that may show different ecophysiological abilities. Our data showed that several genets may last for at least one year belowground and sustain into the next season. Ectomycorrhizal species reproducing by means of spores can form highly diverse and persistent belowground genets that may provide the host tree with higher resilience in a changing environment and enhance ecosystem performance