Breeding of triploid citrus cultivars I. Production of triploids from satsuma mandarin (Citrus unshiu Marc.) X tetraploid ponkan mandarin (Citrus reticulata Blanco) crosses.

摘要

Crosses between satsuma mandarins and tetraploid ponkan (cv. Nakano 3) were made to produce triploid hybrid cultivars. Triploid embryos were obtained from the crosses using 3 seed parents (Ootsu 4, Aoshima and Imamura), which produced comparativelysmall numbers of embryo per seed. Of the 3, the frequency of triploid embryo production per fruit was highest in Aoshima. The frequency of triploid embryo production per seed in undeveloped seeds was higher than that in fully developed seeds. Using the embryo rescue technique, triploid plants were obtained efficiently from the embryos of undeveloped seeds. Tetraploid plants were also obtained from fully developed seed of Ootsu 4 and Aoshima. RAPD analysis showed that all the triploid plants were hybridsand the tetraploid plants were also hybrids or natural autotetraploids. Two hybrid embryos in one seed with identical banding RAPD patterns on agarose gels indicated that the embryos were derived from the same egg cell.