Genetic characterization of apospory in tetraploid Paspalum notatum based on the identification of linked molecular markers

MARTINEZ, ERIC JAVIER; HOPP, E.; STEIN, J.; JUAN PABLO AMELIO ORTIZ; QUARIN, CAMILO LUIS

Molecular Breeding

Kluwer Academic Publishers

Lugar: Amsterdam; Año: 2003 vol. 14 p. 319 - 327

1380-3743

Tetraploid Paspalum notatum bahiagrass is a valuable forage grass with aposporous apomictic reproduction. In a previous study, we showed that apospory in bahiagrass is under the control of a single dominant gene with a distorted segregation ratio. The objective of this work was to identify molecular markers linked to apospory in tetraploid P. notatum and establish a preliminary synthenic relationship with the genomic region associated with apospory in P. simplex.A F 1 population of 290 individuals, segregating for apospory, was generated after cross-ing a completely sexual plant Q4188 with a natural aposporous apomictic plant Q4117. The whole progeny was classified as sexual or aposporous by embryo sacs analysis. A bulked segregant analysis was carried out to identify molecular markers co-segregating with apospory. Four hundred RAPD primers, 30 AFLP primers com-binations and 85 RFLP clones were screened using DNA from both parental genotypes and aposporous and sexual bulks. Linkage analysis was performed with cytological and genetic information from the complete progeny. Cytoembryological analysis showed 219 sexual and 71 aposporous F 1 individuals. Seven different molecular markers 2 RAPD, 4 AFLP and 1 RFLP were found to be completely linked to apospory. The RFLP probe C1069, mapping to the telomeric region of the long arm of rice chromosome 12, was one of the molecular mark-ers completely linked to apospory in P. notatum. This marker had been previously associated with apospory in P. simplex. A preliminary map of the chromosome region carrying the apospory locus was constructed.