EVALUATION OF KENTUCKY BLUEGRASS BLENDS USING ISOELECTRIC-FOCUSING AND COMPUTER IMAGING

Seeds of turfgrass cultivars are commonly blended to improve performan ce. Once physically blended, however, no fast, reliable technique is a vailable to identify the proportions of cultivars present. The objecti ve of this study was to test the effectiveness of computer imaging of electrophoretic gels for determining the relative proportions of two K entucky bluegrass (Poa pratensis L.) cultivars in seed blends based on optical densities of electrophoretic bands unique to each cultivar. B lends of the two cultivars, 'NuStar' and 'Glade', ranging from 0 to 10 0% were prepared by weight, protein extracted and separated on isoelec tric focusing gels stained for esterase activity. The gels were electr onically scanned and their electrophoretic images analyzed using a com puter software program to determine the proportion of each cultivar pr esent in 27 blends. The results indicated that this technique accurate ly quantified the percentages of cultivars in seed blends to within +/ -8.6% with 95% consistency. Based on this study, the combination of is oelectric focusing and computer imaging was an effective method for de termining cultivar proportions in turfgrass seed blends.