EMBRYO SAC DEVELOPMENT IN POLLINATED AND NONPOLLINATED FLOWERS OF 2 APRICOT CULTIVARS

The development of the embryo-sac was studied from anthesis to 10 d la ter in two apricot cultivars, Gitano and Velazquez Fine. In pollinated and non-pollinated flowers, megagametophyte development was very simi lar until 6 d after anthesis, although afterwards it was slightly slow er in pollinated flowers of both cultivars. Over the whole period, 11. 6% and 16.5% of ovules from 'Velaquez Fino' and 'Gitano' respectively were malformed. The percentage of mature ovules in both cultivars reac hed its maximum 10 d after anthesis. Considering the approximate time that pollen tubes need to reach the ovules, factors other than ovule d egradation had to be limiting the amount of fruit set.