Polyploidy, chimera and fertility of interspecific cassava (Manihot escuJenta Crantz) hybrids

Abstract

Four interspecific hybrids between cassava and wild Manlhot species were polyploidized by colchicine application to buds of cuttings. Totally tetraploid types as well as sectorial and periclinal chimeras were produced. Somatic selection applied to lateral buds of sectorial chimeras induced totally tetraploids. Fertility was restored in the sterile interspecific hybrids by chromosome doubling up to 93% viable pollen production in the tetraploids compared to 13% In diploids, which could lead to the evolution of new Manihot species. Periclinal chimeras showed high vigour compared to both tetraploid and diploid plants.