Isoenzymatic variability in wild potatoes

Two species of wild potato Solanum commersonii, subspecies commersonii and malmeanum, and S. chacoense, subspecies muelleri occur in southern Brazil. Their rusticity and easy adaptation to extreme climatic conditions make the m valuable for breeding programs. The objective of this work was to analyze the isoenzymatic variability of 113 clones of wild potato subspecies. They were collected and maintained at Embrapa-Centro de Pesquisa Agropecuaria d e Clima Temperado, at Pelotas, RS, Brazil. Enzymes involved in energetic (g roup I) or in peripherical (group Il) metabolism constituted the material u sed. Polyacrylamide horizontal gel electrophoresis was used to analyze pero xidase, aspartate transaminase, phosphoglucomutase and isocitrate dehydroge nase isoenzymes. Solanum spp. has considerable genetic variability for isoe nzymatic patterns. Cluster analysis classified the clones into 51 subgroups , based on electrophoretic variants of group I enzymes, and into 89, when g roup Il enzyme variants were added. Genotypic differentiation of S. chacoen se muelleri in relation to S commersonii commersonii and S. commersonii mal meanum is evident when expressed through similarity and cluster analysis.