Plant & Animal Genome IX Conference Plant & Animal Genome IX Conference
Workshop: Forage & Turfgrass
W25_09.html
The transition from vegetative to reproductive development is important in many plant species and is of particular importance in forage and turfgrasses. The annual/perennial ryegrass complex provides a unique opportunity to study genes controlling the transition to flowering in cool-season forage and turfgrasses. An annual/perennial ryegrass three generation mapping population of 170 individuals has been developed and is being evaluated for vernalization and photoperiod requirements. Progeny were scored for time to flowering at 8, 16, and 24 hour photoperiod under both vernalized and unvernalized conditions. Fluorescent AFLP markers were scored on the segregating progeny using a double pseudotestcross mapping strategy. More than two hundred markers were scored for each of the F1 parents and used to develop two genetic maps. Data for vernalization control of flowering fit a two gene dominant and recessive epistasis model similar to that observed in spring/winter barley crosses. Data for flowering under 8hr photoperiod following vernalization suggests one major gene influences flowering under short daylenghts. RFLP markers linked to genes influencing vernalization and photoperiod requirements in spring/winter barley crosses are being evaluated to determine the level of synteny that exists between these two systems. Additional RFLP markers will be scored to establish the level of synteny between ryegrass and other Triticeae genomes. The results of map development, markers for assisted breeding, and Quantitative Trait Loci evaluation of flowering control will be presented.