PRODUCTION OF TERTIARY TRISOMICS IN RICE (ORYZA-SATIVA L)

Tertiary trisomics, cytogenetical variants with an interchanged chromosome in addition to the normal chromosome complement, were produced through systematic three-way crosses (primary trisomics/reciprocal translocations//normal disomics) in rice (Oryza sativa L.). Twenty-five tertiary trisomics were selected on the basis of their morphology and seed fertility in the F1 progenies of the three-way crosses. They were identified by observations of the breeding behavior of their selfed progenies and of chromosomal configurations at meiosis. As the tertiary trisomics produced in this study are useful for chromosome mapping, additional production of tertiary trisomics is under way.