In vitro germination of embryos for speeding up seedling development in olive breeding programmes

The germination potential of olive seeds without the sclerified endocarp (stoneless seeds) and growth of the seedlings were compared with germination and growth of excised and in vitro cultured embryos of ten olive cultivars. The number of empty stones and the number of stones with two seeds were also determined for each of the cultivars. Isolated embryos of all the cultivars germinated uniformly within 10-14 days in culture, while the mean germination time of stoneless seeds was 55-95 days depending on the cultivar. The percentage of embryo germination was 3-15 fold higher than that of stoneless seeds according to cultivar. Root growth was more rapid in plants originating from seeds than from excised embryos. The growth of plantlets derived from in vitro germinated embryos in the greenhouse was normal. Thus, embryo culture would increase the efficiency and shorten the time for starting initial progeny evaluation of olive breeding programmes. (C) 1997 Elsevier Science B.V.