ALLOZYME MARKERS SUITABLE FOR PASTURE PERSISTENCE STUDIES IN COCKSFOOT (DACTYLIS-GLOMERATA) CV GRASSLANDS WANA

Allozyme variation in the tetraploid cocksfoot (Dactylis glomerata) cv. Grasslands Wana was studied with a view to establishing a set of genetic markers that would enable this cultivar to be distinguished from resident cocksfoot populations. Such markers would enable the persistence of 'Grasslands Wana' in hill country pastures to be monitored following oversowing, via the estimation of the admixture proportion of the cultivar in the resulting pasture mixture. Three of the six enzyme systems studied proved to be polymorphic, yielding four marker loci: Mdh-1; Pgm; and the isolocus Gpi-1,2. Five alleles were found for Gpi-1,2, with frequencies ranging from 0.04 to 0.55. For Pgm three alleles of intermediate frequency were found, 'and Mdh-1 showed two alleles with frequencies of 0.91 and 0.09. These loci will provide a useful tool for following the persistence of 'Grasslands Wana' in a mixed pasture, provided the genotype and allele frequencies of the resident pasture populations differ suffficiently from those of 'Grasslands Wana' to allow reliable estimates of admixture proportions.