CO-SEGREGATION OF DNA MARKERS WITH TRIPSACUM FERTILITY

Genetically related triploid populations of Tripsacum dactyloides segr egating for sterility were shown to co-segregate with particular RFLP markers. While the percentage of seedset varies within apomictic popul ations, it is known that sterility, the absence of seed, is associated with sexual reproduction in triploid populations. Given this, it is o f interest that five out of 25 RFLP markers showed co-segregation with the phenotype, percent seedset, scored on 86 individuals. This subset of markers was chosen based on its coverage of the current Tripsacum RFLP linkage map. These five markers are known to be linked to tile Tr ipsacum linkage groups A, F, H, I, and L, and are syntenic in maize to chromosomes 1, 7, and 6. It is significant that the five Tripsacum li nkage groups discussed here have syntenic regions in maize. Specifical ly these maize regions harbor genes regulating male sterility, defecti ve kernel development, and gametophyte and fertility associated genes.