A Comparison of Stem Peroxidases in Bush and Vine Forms of Squash (Cucurbita maxima Duch.and C. pepo L.)

Total peroxidase activities and peroxidase isozymes were comparedamong 10 bush- and vine-squash cultivars of Cucurbita maximaDuch. and C. pepo (L.) Several qualitative variations of isozymeswere detected between C. maxima and C. pepo, and some differenceswere evident among varieties of C. pepo. There were no qualitativedifferences between genetically similar bush and vine strains.Quantitative differences were difficult to resolve, althoughit did appear that in varieties of C. maxima exhibiting lowlevels of peroxidase activity, isozymes C₃, C₄, and C₆ wereless intense. Depending upon the cultivars compared, total peroxidase activityin bush forms was either higher or lower than, or the same astheir vine counterparts. Since the major bush genes in the varietiesstudied are believed to be allelic, the results indicate thatthe over-all genotype of squash varieties can influence therelative expression of peroxidase activity between bush andvine forms.