Segregation analysis of RFLP markers reveals a tetrasomic inheritance in apomictic Paspalum simplex.

Apomictic tetraploid Paspalum simplex was crossed with colchicine-doubled diploid sexual plants belonging to the same species. Homologous genomic probes were selected from a partial PstI genomic library for their capacity to detect alleles specific to the apomictic parent, and their segregation was analyzed in the F1 progeny. High levels of polymorphism between apomictic and sexual genotypes were recorded. The heterozygosity was high in both tetraploid and diploid genotypes but the differences between them were not as great as expected. In the sexual parent, some markers segregated as either a monoallelic duplex or a diallelic duplex, while several allelic configurations were observed in the apomictic parent. The segregation of double-dose monoallelic fragments demonstrated the tetrasomic inheritance of apomictic P. simplex. The correlations between apomixis, ploidy level, and tetrasomic inheritance are discussed.Key words: apomixis, tetrasomic inheritance, Paspalum simplex, molecular markers.