Identification of trisomics in diploid lucerne (Medicago sativa)

Abstract

Nine trisomics (including one double trisomic) derived from diploid and tetraploid Medicago sativa L. and M. falcata L. were examined at the pachytene stage of meiosis, and the extra chromosomes were tentatively identified on the basis of pachytene chromosome idiogram descriptions. Although identification of chromosomes involved in trivalent formation was not always possible, the trisomic chromosome could often be identified on the basis of its failure to form bivalents. Trisomics for five of the eight chromosomes were identified. Positive establishment of trisomic lines now requires the use of linkage data to confirm chromosome identities.