IDENTIFYING CRABAPPLE CULTIVARS BY ISOZYMES

Forty-five crabapple (Malus spp.) cultivars were evaluated for 16 isoz yme systems by starch gel electrophoresis. Of the 16 systems evaluated , 6 were useful in separating among cultivars. Enzyme systems used to distinguish among the cultivars included alcohol dehydrogenase, aspart ate aminotransferase, malate dehydrogenase, 6-phosphogluconate dehydro genase, phosphoglucoisomerase, and shikimate dehydrogenase. Each enzym e system produced one well-resolved polymorphic region except for 6-ph osphogluconate dehydrogenase, which produced two. Most crabapple selec tions could be identified when all six enzymes were evaluated. Alcohol dehydrogenase had the most diagnostic banding patterns useful for cul tivar identification.