XVI International Botanical Congess

In apomictic species, progeny may be formed by apomictic reproduction (2n+0), the hybridization of rare sexual genotypes (n+n), or through the fertilization of unreduced gametes (2n+n). In this paper we will review the vegetative and reproductive fitness of progeny resulting from controlled intra- and interspecific hybridization in buffelgrass, Pennisetum ciliare (L.) Link. [Cenchrus ciliaris L.] Buffelgrass is an aposporous, polyploid, perennial C4 grass that has been widely planted for pasture and conservation throughout the semi-arid tropics. Because apomictic reproduction is simply inherited in buffelgrass, forage improvement efforts have focused on the hybridization of rare sexual genotypes with apomictic genotypes, and the subsequent selection, evaluation, and release of apomictic hybrids. This program has allowed us to compare the fertility, pollen quality, height, biomass, etc) of several hundred 2n+0, n+n and 2n+n progeny. On average apomictic (2n+0, 2n+n, and n+n) progeny exhibit greater mean vegetative and reproductive fitness than sexual progeny (n+n), although occasional sexual progeny were identified that exhibited higher levels of fertility and vegetative vigor than their apomictic counterparts.