EFFECT OF OVULE POSITION ON SEED MATURATION AND SEED WEIGHT IN ULEX-EUROPAEUS AND ULEX GALLII (FABACEAE)

We examined the effect of ovule position within the pod on the probabi lity of seed maturation and on seed weight in two woody legumes, Ulex europaeus and Ulex gallii. Results showed that ovule position had a si gnificant effect on the probability of seed maturation in both species . Ovules in a central position were found to have a higher probability of maturation in U. europaeus, whereas those in a stylar position wer e favored in U. gallii. Ulex europaeus showed no effect of position on seed weight. The smallest seed within the pod was more frequently at stylar positions in U. gallii. These results might be explained by sev eral non-exclusive hypotheses: time of fertilization, constraints on s eed development (e.g., fruit shape and access to maternal resources), and genetic quality. The effects of seed weight on progeny performance estimated as probability of germination and seedling weight were test ed in a laboratory experiment. Neither U. europaeus nor U. gallii exhi bited any effect of seed weight on the probability of germination. How ever, seedling weight was dependent on seed weight in both species.