Cytotaxonomic Studies in the Genus Sorghum III. The Polyploid Species of the Subgenera Para-Sorghum and Stiposorghum

Publisher Website
Google Scholar
Abstract
Sorghum leiocladum and S. australiense (Para-Sorghum) and S. plumosum (Stiposorghum) with a somatic chromosome number of 20 are tetraploid spp. From 1-5 quadri-valents per pollen mother cell occur at diakinesis and metaphase I in each species. A hexaploid S. plumosum with at least 1 hexivalent per pollen mother cell was found. These spp. were considered to be autopolyploids. The orientation of quadrivalents at metaphase I in S. leiocladum was not directed, open and zig-zag configurations occurring with approximately equal frequencies; the orientation of quadrivalents at metaphase I in S. australiense and S. plumosum was directed, the zigzag configuration occurring with a frequency of 87-97%. Chromosomes of the multivalents in the hexaploid S. plumosum were predominantly alternately distr. at the same stage. The directed orientation was considered to be genetically detd. It was proposed that a species not displaying a directed orientation of the chromosomes in an interchange complex may not display a directed orientation of the quadrivalents in an induced autotetraploid (example: Zea mays); a species displaying a directed orientation of chromosomes in an interchange complex may display a directed orientation of the quadrivalents in an induced autotetraploid (example: Oenothera).

This publication has 0 references indexed in Scilit: