Germination and seedling establishment in bilberry (Vaccinium myrtillus L.) in Central Italy

The bilberry is a spontaneous dwarf shrub with potential for national and international markets because its fruits have food and medicinal uses, being considered an important source of sugars, antioxidants, vitamins and minerals. Request of bilberry fruits is constantly increasing, but the land area covered in bilberry bushes and the locally collected berries have declined in Central Italian Apennine in these last decays. Freshly matured seeds of the dwarf shrubs Vaccinium myrtillus were tested for germination before and after cold stratification and air room storage under different light conditions and temperatures. Thereafter, seeds were in vivo and in vitro germinated on different soil types and culture media under the best assessed conditions. The optimal conditions for germination of bilberry seeds were: freshly mature seeds, 16-h photoperiod, temperature of 22.5±0.5°C. In initial test, seeds germinated to 66-76% at 22.5°C and 25°C, with very few seeds germinating at 15°C (8%); darkness had always a negative influence on the germination capacity. However, after cold stratification germination increased significantly at 15°C, both in light (51%) and darkness (24%); thus, seeds of this species are conditionally dormant at maturity. Although the effect was different depending on temperature and light condition, cold seed stratification had an overall negative effect on all the considered germination parameters, and seed viability was strongly reduced after storage at room temperature for 90 days. The germination substrate did not significantly affect the final germination percentage, that reached almost 62-78% on average. The temperature proved to be the most influential physical factor on bilberry seed germination. Seedlings obtained by in vivo experiments showed a good development, however additional studies are necessary to support the definition of a standardized commercial protocol for seedling production.