EVALUATION OF ABILITY TO PRODUCE NATURAL TRIPLOID FROM DIPLOID CROSSES IN DIFFERENT CLEMENTINE’S CULTIVARS

Seedlessnessis an important economic trait relating to fruit quality. For that, Citrus breeding programs focused on the development of seedless cultivars by triploidy way. The triploid citrus can be produced by natural hybridization. On the other hand, Clementine’s cultivars were usually used as female’s parents because of the self-incompatibility and mono-embryony. In this paper, we evaluate 23 Clementine's cultivars for the ability to produce spontaneously undeveloped seeds which contain triploids embryos. At the fruit maturity, all seeds were extracted and classified according to their shape. But, only undeveloped seeds were cultured in Murashige and Skoog medium with 1 mg/l of gibberilic acid. Then, all seedlings were analyzed by flow cytometer. The clone which can produce a large number of undeveloped seeds is Muska followed by Berkane, but the clone characterized by a germination rate and regeneration significant is Hernandina followed by Courtois, Bruno and Georges Pourreyron. While, the clementines Nour and Cadoux proved to be less able to produce abnormal seeds. The triploidy rate varied from 0% in Nules S, Ain Taoujdat, Nules E, Nour, Muska and Cadoux to 50% in Berkane and Wase. The average triploidy rate is 26.35% and the highest level of triploidy varied from 39% at Hernandina to 33% at Courtois. Studies have shown the importance of the best choice of female parents for optimizing the spontaneous production of 2n gametes in diploids crosses. Clementine Hernandina can be used as the best female parent to receive spontaneous pollination to produce triploids hybrids.