SEGREGATION ANALYSIS OF RFLP MARKERS REVEALS A TETRASOMIC INHERITANCEIN APOMICTIC PASPALUM SIMPLEX

Apomictic tetraploid Paspalum simplex was crossed with colchicine-doub led diploid sexual plants belonging to the same species. Homologous ge nomic probes were selected from a partial PstI genomic library for the ir capacity to detect alleles specific to the apomictic parent, and th eir segregation was analyzed in the F-1 progeny. High levels of polymo rphism between apomictic and sexual genotypes were recorded. The heter ozygosity was high in both tetraploid and diploid genotypes but the di fferences between them were not as great as expected. In the sexual pa rent, some markers segregated as either a monoallelic duplex or a dial lelic duplex, while several allelic configurations were observed in th e apomictic parent. The segregation of double-dose monoallelic fragmen ts demonstrated the tetrasomic inheritance of apomictic P. simplex. Th e correlations between apomixis, ploidy level, and tetrasomic inherita nce are discussed.