Abstract
Peroxidase isozyme activities were examined to compare the usefulness of various tissues under different environments for estimating interspeclfic differences between two potato species. Solanum pinnatisectum and S.multidissectum. A total of sixteen peroxidase isozyme bands were distinguished in the two species. The expression of these bands changed depending on species and tissue sources as well as environmental conditions. The environmental effect was larger in leaf tissues than in tuber tissues, and larger in S.multidissectum than in S.pinnatisectum. S.pinnatisectum and S.multidissectum had four and two species-specific bands, respectively, of which four were unique either to leaves or tubers and the remaining two were common to both tissues. These species-specific bands are useful to distinguish between the two species. Based on total band activities including non-specific ones, a mean Euclidean distance was utilized to estimate an interspecific difference between them. Both tuber and leaf tissues gave significant interspecific differences under the controlled environment. Our study thus indicates that leaf tissues, like tubers, can provide a useful material in peroxidase isozyme analysis in Solanum species.
