Skip to main content
ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #130560
Title: SPECIES MARKER SEGREGATION IN A WIDE CROSS LOLIUM MAPPING POPULATION

Author
item WARNKE, SCOTT - OSU CROP & SOIL SCIENCE
item Barker, Reed
item BRILMAN, LEAH - SEED RESEARCH OF OREGON

Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 1/10/2002
Publication Date: 1/10/2002
Citation: WARNKE, S.E., BARKER, R.E., BRILMAN, L.A. SPECIES MARKER SEGREGATION IN A WIDE CROSS LOLIUM MAPPING POPULATION. PLANT AND ANIMAL GENOME ABSTRACTS. 2002. Paper No. W168.

Interpretive Summary: Transition from vegetative to reproductive development is important in many plant species and is of particular importance in forage and turfgrasses because flowering spikes reduce forage or turf quality. The annual/perennial ryegrass complex provides a unique opportunity to study genes controlling the transition to flowering in cool-season forage and turfgrasses. We developed annual/perennial ryegrass three generation mapping population of 170 individuals and it was evaluated for vernalization (cold treatment before flowering) and photoperiod (day length) requirements. Inheritance of a superoxide dismutase locus (Sod-1), a phosphoglucose isomerase locus (Pgi-2) and several other isozyme and AFLP loci that significantly influence flowering time were evaluated. We found that vernalization control of flowering fit a two gene dominant and recessive epistasis model similar to that observed in spring/winter barley crosses. Sod-1 and Pgi-2 were inherited as single gene markers. These markers are known to be linked to genes influencing vernalization and photoperiod requirements in spring/winter barley. Our results can be used to help develop a test to distinguish annual from perennial ryegrass, and to assist breeders in developing varieties that have more uniform growth habits. A more accurate determination of annual vs perennial growth habit test could save seed growers between $5 and 7 million annually.

Technical Abstract: Annual and perennial ryegrasses are important turf and forage grass species grown throughout the world. These two species differ in many morphological and growth habit characteristics. This study was conducted to identify marker loci and genomic regions important in species separation of annual and perennial ryegrass. Inheritance of a superoxide dismutase locus (Sod-1), a phosphoglucose isomerase locus (Pgi-2) and several other isozyme and AFLP loci that significantly influence flowering time were evaluated in a three generation annual X perennial ryegrass mapping population. The molecular form of the Sod-1 locus was determined by H2O2 and KCN inhibitor and indicated that the Sod-1 and Sod-2 loci were both Cu/ZnSod enzymes. Segregation data indicated that the Sod-1 locus fit expected ratios for a single locus with two alleles. The common alleles at the Sod-1 locus were scored in 13 annual and 24 perennial ryegrass cultivars to determine the potential of this locus for species separation. The Sod-1b allele was homozygous in 98% of perennial ryegrass individuals from 24 cultivars indicating that this allele may be an indicator of perenniality. All eight annual ryegrass cultivars originating in Europe or Asia had a low frequency of Sod-1b homozygous individuals, but the five cultivars originating in the Western Hemisphere had genotype frequencies for homozygous Sod-1b up to 56%. The potential of these markers for developing a replacement test for seedling root fluorescence will be discussed.