Cytogenetics of Trisomics in Rice

抄録

A natural triploid isolated from a diploid population of T. 1242 has been used for establishing trisomics for linkage group studies. The triploid plant when cytologically analysed at pachytene showed chromosomal differences indicating its allo-polyploid nature. The triploid was used as a female parent in triploid-diploid crosses for the synthesis of trisomics. Morphological variations of the trisomics corresponding to chromosomal differences have been studied. Trisomics showed morphological variations with partial sterility. These variations have been found to be associated with specific chromosomes present as extra in these plants. Five out of twelve (n=12) types of chromosomes have been associated with certain diagnostic morphological traits indicating their relationships with specific linkage groups. Correlations of the morphological traits of triploid-diploid progenies in the F₂ with their respective chromosomal set up have also been computed with a view to detecting linkage relationships.