THE PERSIMMON BREEDING PROGRAM AT IVIA: ALTERNATIVES TO CONVENTIONAL BREEDING OF PERSIMMON

In the Mediterranean area, the production of persimmon (Diospyros kaki Thunb.) [2n=6x=90] has increased recently as an alternative to the major fruit crops. In Spain, production relies almost exclusively on the cultivar ‘Rojo Brillante’ which accounts for the 83% of the crop. A crop based on a monovarietal culture implies several commercial and phytosanitary risks that could compromise the future. The breeding program started at IVIA in 2002 and it is aimed at increasing the range of cultivars available for the crop by producing new cultivars as an alternative to the cultivar ‘Rojo Brillante’. The main objective is to extend the harvest season and to obtain cultivars from the PCNA type. There are several facts that make it difficult to obtain PCNA fruits, the dominance of the inheritance of the fruit astringency, the limited number of cultivars bearing male flowers and the hexaploid nature of the main cultivars. All together it is difficult to obtain PCNA fruits by conventional breeding. The strategy of selected crosses among PCNA type cultivars resulted in negative effects of inbreeding, due to the low genetic diversity of the PCNA type cultivars. Besides the conventional breeding, at IVIA we have explored mutagenesis as a method for developing new cultivars. In the present paper we show the results obtained by mutagenesis and conventional breeding of persimmon. Both methods are complementary. The effectiveness of the methods and the genotypes obtained are discussed. Mutagenesis is an alternative method for generating diversity into persimmon.