Interchange Trisomics of Pearl Millet (Pennisetum americanum (L.) K. Schum): Its Cytomorphology, Fertility and Transmission

抄録

Twenty five interchange trisomics were isolated from an interchange trisomic and six translocation heterozygotes of pearl millet (2n=14). Morphology and fertility of these trisomics varied from plant to plant and season to season. Cytological analysis of these trisomics indicates that chromosome associations of trivalents and univalents were frequent with comparatively less frequency of _??_₄ and pentavalents in all the trisomics studied. Other associations were relatively infrequent. Transmission rate and breeding behaviour of 18 interchange trisomics were studied for three seasons of the crop and it was found that average frequency of primary trisomics was more than that of other trisomics (tertiary and interchange). The possible causes of differential transmission rates of different trisomics have been discussed.