SELF-INCOMPATIBILITY AND EFFECT OF RECIPROCAL CROSS AND OPEN POLLINATION ON FRUIT SET AND FRUIT CHARACTERISTIC IN JORDANIAN ALMOND LANDRACES

Limited studies were carried out to identify self- and cross-compatibility relationships among Jordanian almond landraces. Therefore, this study aimed at studying the level of self-incompatibility and the effect of cross and open pollination on fruit set and shell, nut and kernel related traits in almond. To achieve this objective, field experiments were carried out during 2012 and 2013 cropping season on five Jordanian almond landraces and one wild bitter almond (A. communis) available in the farmer's fields at Ajloun district, Jordan. Fruit set was recorded in the field after open-pollination, self-pollination by bagging the branches with flower buds and cross pollination after emasculation of the floral buds. All almond genotypes showed complete self-incompatibility. Genotypes showed variable percentages in fruit set with similar trend in the two growing seasons. Following cross pollination treatment, genotypes exhibited fruit set ranging from 40.3% in Hajari to 94.0% in Fark and from 34.1% in Mukhmaly to 93.3% in Fark in 2012 and 2013, respectively. Results showed that cross pollination of Hami Hallo (79.7-81.7 and 77.8-89.2% in 2012 and 2013 respectively) and Fark (83.0-94.0 and 86.1-93.3% in 2012 and 2013 respectively) with other landraces led to high level of fruit set indicating high cross-incompatibility. Slight differences were recorded in fruit set in reciprocal crosses. Pollen source did not affect shell, nut and kernel traits. As a conclusion, results obtained from this study showed that, all of the genotypes were self in-compatible and all genotypes showed high level of cross-compatibility with variable degree among genotypes.