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 gen etic markers that would enable this cultivar to be distinguished from resident cocksfoot populations. Such markers would enable the persiste nce of 'Grasslands Wana' in hill country pastures to be monitored foll owing oversowing, via the estimation of the admixture proportion of th e cultivar in the resulting pasture mixture. Three of the six enzyme s ystems studied proved to be polymorphic, yielding four marker loci: Md h-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 o f intermediate frequency were found, 'and Mdh-1 showed two alleles wit h 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 al low reliable estimates of admixture proportions.