Influence of Seed Nitrogen and Carbon on Germination in Different Populations of Stone Pine

Stone pine (Pinus pinea L.) is mostly known for its edible kernels, which have been used for human consumption since Paleolithic times because of its highly nutritive value including high fat and protein. It is an important tree species in the Mediterranean basin, and one of the five native pine species in Turkey. Stone pine is also a crop in agroforestry in Mediterranean climate zones. Germination traits, carbon (C) and nitrogen (N) concentrations, C/N, carbon mass (CM) and nitrogen mass (NM) were investigated in seed lots of five native stone pine populations of Turkey. Significant differences were found among populations in terms of seed C and N concentrations. Seed germinations were conducted at 15 oC, 20 oC and 25 oC temperatures for 28 days. Germination percentage (GP) at 20 °C was the highest in all populations and up to 93%. The highest mean germination time (MGT) was 25 days at 15 °C and the minimum MGT was 13 days at 20 °C. C and N concentrations were 61–63% and 7.3–8.0%, respectively. The magnitude of the variance of C, N, C/N, CM and NM among the populations was 16%, 55%, 54%, 13%, and 16% respectively. MGT-N% (R2 = 0.88) and MGT-C/N (R2 = 0.78) at 20 °C and MGT-(C%-N%) (R2 = 0.95) at 15 °C indicated clearly the influence of C and N on seed MGT. Strong relationships suggest that stone pine seed carbon and nitrogen can be used as a relevant and fast assessment of seed viability in the context of nursery and afforestation techniques.