Plant & Animal Genome IX Conference

Workshop: Fruit/Nut Tree
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APPLICATION OF FISH AND GISH TECHNIQUES TO THE CHROMOSOME ANALYSIS OF DIOSPYROS SPP.

Laboratory of Pomology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan

Four ploidy levels, diploid, tetraploid, hexaploid, and nonaploid, were reported in the genus Diospyros with a basic chromosome number of x = 15. Most wild species in Diospyros are reported to be diploid (2n = 30), whereas common cultivated species of Diospyros, Japanese persimmon (D. kaki), is either hexaploid (2n = 90) or nonaploid (2n = 135). It has been speculated, therefore, that several wild diploid species of Diospyros were involved in speciation of D. kaki. There have been, however, only a few reports describing the origin of D. kaki and its genome composition, probably because chromosomes in Diospyros, especially those of polyploid species, are small in size and large in number. GISH and FISH have been recently developed and effectively used for chromosome analysis. We have been applying the technology to the chromosome analysis of D. kaki and several other Diospyros spp. The results obtained so far will be presented.