Relationship between seed biomass, germination time and seedling growth in Olea europea

Olive plants for commercial production are vegetatively propagated by cutting and grafting. While genetic identity can be maintained by "own root"; plants by cutting, the grafted plants may show different growth characteristics due to the influence of the rootstock. The selection of mother plants, able to produce seeds with desirable characteristics and rootstocks that may control seedling growth in grafted stock, can be an objective of study to facilitate the development of olive breeding programmes.The relationship between seed biomass, mineral nutrient reserves, time to germination and seedling growth was analysed for six cultivars of Olea europaea. The cultivars, exhibiting initial differences in seed biomass, differed significantly with respect to germination capacity, germination time and mineral content. Significant variation among cultivars was also evident in the linear growth of seedlings, evaluated at different intervals from 2 to 30 weeks. The seeds from all six cultivars exhibited low germination. There is a significant effect of cultivar on the levels of single mineral nutrient content of seeds, high concentrations of N and significant concentrations of K, P, Mg, and Ca were detected. Seed biomass was not related to time to germination and the levels of single nutrients of the seeds themselves. For seed tissue, significantly positive correlations existed only between K, and Mg concentrations. Seed biomass was positively and significantly related to root biomass. The seedlings obtained from larger seeds showed a substantially greater proportion of' biomass to roots. Some root traits may be important for survival and the establishment of' the seedlings, not least under conditions of limited water availability.