Genome Homology and Origin of Panicum sumatrense (Gramineae)

Abstract

Interspecific hybrids between Panicum sumatrense and P. psilopodium were produced and analyzed to assess the genome homology between these two taxa. Meiotic behaviour was perfectly normal in both the parental species, P. sumatrense and P. psilopodium. Regular 18 bivalents were observed in the parents and they are allotetraploid. Both the parents are fully fertile. In the hybrids a mean chromosome pairing of 17.9 II+0.035 IV per cell was found in 200 cells analyzed. About 96% of the PMCs contained 18 bivalents. Regular 18 bivalent formation in the hybrids strongly suggests that the genomes of P. sumatrense and P. psilopodium are basically similar and are fully homologous. Thus P. sumatrense or sama millet might have originated from wild taxon P. psilopodium through selection and further cultivation. Presence of a single quadrivalent in the hybrid indicates the genomic divergence and differentiation in these two species through one reciprocal translocation.