Inter- and intra-population variation of a South American beech in germination traits.

BARBERO, FERNANDO; GALLO, LEONARDO ARIEL; PASTORINO, MARIO JUAN

Bugos

Simposio; COST E52, Final Meeting Genetic Resources of European Beech; 2010

European Science Foundaton COST E52

Nothofagus is an emblematic genus of the southern hemisphere represented in the temperate Patagonian forests of Argentina by six species. N. obliqua, one South American “cousin” of Fagus sylvatica with high breeding potential, is the target of a domestication program in Argentina, in the frame of which field and nursery trials are being conducted. Here, we present the results of a germination analysis performed under controlled conditions. Each of 101 open pollinated families corresponding to seven natural populations (13 to 15 families per population) were represented by 400 seeds distributed in four germination trays and arranged in a four-block experimental design. Seeds were surveyed every 48 hours during 38 days recording the number of germinated seeds. Germination capacity (GC) was the relative number of germinated seeds at the end of the trial. A Gompertz exponential curve was fitted to the cumulative germination data for each repetition of each family, thus estimating germination energy through the slope parameter of the curve (S) and the time at the maximum germination rate (T). Significant differences among populations were shown for these three variables through an ANOVA test with a mixed model with random families nested within fixed populations. In fact variation was quite large, since one population had a mean GC of 1.5% while another rose till 57%. Family factor resulted significant for the three variables too, with mean GC ranging from nil to 77%. Maternal effects are important at this stage; however, the observed variation seems a promising trend when thinking on conservation and genetic improvement.