Evaluation of parthenocarpy ability in different citrus genotypes

Citrus breeding programs focused to produce seedless varieties need to increase the knowledge about the parthenocarpic ability (PA) of the different citrus genotypes used as parents in sexual hybridizations. Current information is insufficient and in some cases contradictory. In this context, ten citrus genotypes were assessed for their PA including Campeona, Imperial, Saltenita, Fortune and Moncada mandarins, Clemenules and Monreal clementines, Tardia Picana satsuma, Ellendale tangor and Pink pummelo. We used terminal flowers at balloon stage and performed the following treatments: 1) hand-cross-pollination with FOrtune and bagged (Clemenules was used for Fortune due the self-incompatibility of Fortune, 2) hand-self-pollination and bagged, 3) emasculated and bagged, 4) bagged and 5) open pollination. About 100 flowers were used for each treatment and were repeated in two consecutive seasons. Fruits were collected when ripe and data of fruit set, number of seeds per fruit and fruit weight were redorded. Different levels of PA were observed; Tardia Picana satsuma showed the highest level of PA followed by Moncada, CLemenules, Imperial and Pink pummelo. Campeona, Ellendale and Saltenita displayed a low level of PA, whereas Fortune and Monreal (a self-compatible Clementine) do not show PA and needs the stimulus of pollination for fruit development. In addition, we observed different relations between fruit size and seed number depending on the genotype. These results have been used for parental combination strategies in our triploid breeding program. (Texte intégral)