Cytological Studies in Digitaria pentzii Stent

Abstract

Fourteen accessions of Digitaria pentzii have been studied cytologically: Ten of them are tetraploids, two are triploids, one is a diploid and one is a aneuploid. Observations made on chromosome configurations at diakinensis and metaphase 1 in polyploids, together with preliminary studies on gross morphology of pachytene chromosomes, indicate that the tetraploids are allopolyploids and the triploids are autopolyploids. Elimination of chromatin material through B-chromosome process following translocation is cited as one of the mechanisms for the occurrence of aneuploids.