YEAR-TO-YEAR VARIATION IN THE DEVELOPMENTAL STAGE OF THE EMBRYO SAC AT ANTHESIS IN FLOWERS OF APRICOT (PRUNUS-ARMENIACA L)

Examination over several years of the stage of development of ovules a t anthesis in eight cultivars of apricot reveals that, in the mild Med iterranean climate of Murcia, ovules are late in developing in compari son with other species. Frequently, ovules were found where there was no sign of the embyro sac. Sacs with two or four nuclei are very scarc e and ovules with the egg cell differentiated were hardly found. Altho ugh flowers were collected at the same external stage of development, there were substantial differences in the degree of embyro sac develop ment.