2012 Volume 15 Issue 3+4 Pages 53-59
The genome size, basic chromosome number, and ploidy of genus Pennisetum varies among species. We isolated one new repetitive sequence each from P. orientale (PoSat1) and P. villosum (PvSat1) and two new repetitive sequences from P. setaceum (PsSat1 and PsSat2). The unit length of these repetitive sequences was 152–192 bp and no homology was seen between them. These sequences were located in the subtelomeric regions in a limited number of species. PoSat1 was highly repeated in P. orientale and P. flaccidum, and moderately repeated in P. villosum and P. setaceum, while other species had a lower number of this repeat. PvSat1, PsSat1, and PsSat2 were species-specific. These subtelomeric repeat sequences were mostly amplified in species with small chromosomes. We also examined the distribution of the repetitive centromeric sequence isolated from P. glaucum. This sequence tended to be repeated in species with large chromosomes. Here, we discuss the evolution of these repetitive sequences in Pennisetum.
