Paternal and maternal effects on seed characteristics of olive cultivars.

Characteristics of seeds of Carolea and Kalamon cultivars, derived from self, cross and open pollination, were taken in consideration. In cross pollination, pollens of Arbequina, Carolea, Frantoio, Kalamon, Leccino, Maurino, Moraiolo, Nostrale di Rigali and Orbetana were used. Up to 5.1% of fruits of cv. Carolea derived from open-pollination was bi-seeded, while in Kalamon it was only 3.0%. In self-pollinated fruits of Carolea, 16.7 % was aborted and no bi-seeds were found, while 8.9 % and 6.5 % of self-pollinated fruits of Kalamon were respectively aborted and bi-seeded. In Carolea among the tested pollinizers, Dolce Agogia and Frantoio determined the lowest percentages of aborted seeds (6.9 and 8.2), while Moraiolo and Nostrale di Rigali didn’t effect bi-seeding. Paternal effects were observed on fruit characteristics of Kalamon: pollen of Dolce Agogia determined 33.3 % of bi-seed fruits and 22.2% of aborted seeds, followed by Nostrale di Rigali and Orbetana. The presence and number of viable seeds per fruit affected fruit size on both cultivars. In general the absence of seed determined smaller fruits due to a smaller endocarp. In cv. Carolea the biggest seeds were found in free-pollinated fruits with only one viable seed, while in cv. Kalamon the biggest fruits were recorded in open and self – pollinated fruits. In cv. Carolea fruits containing two viable seeds were heavier due to larger fruit components, while in cv. Kalamon two seeds per fruits dind’t seem to influence significally the fruit size compared to those containing only one seed.