Seventy Cymbidium (Swartz.) cultivars were analyzed for isozyme variability in eight enzyme systems by starch gel electrophoresis. All systems studied [aspartate aminotransferase (AAT), malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), phosphoglucomutase (PGM), glucose phosphate isomerase (GPI), triosephosphate isomerase (TPI), and shikimate dehydrogenase (SKDH)] showed polymorphism. When all enzyme systems were evaluated, 68 of the 70 Cymbidium cultivars could be distinguished. Isozymes could not distinguish betwen the cultivars Golden Star `Kumamoto' and Golden Star `Sunrise'. No cultivar showed a single unique pattern, but the TPI system gave one “diagnostic” pattern. Segregation ratios from controlled crosses suggested that LAP-1 is simply inherited and controlled by at least two alleles.
P. Obara-Okeyo, Kouei Fujii, and Shunji Kako
P. Obara-Okeyo, K. Fujii, and S. Kako
Eight enzyme systems were used to study electrophoretic variability among 12 species of Cymbidium Swartz and to assess phylogenetic relationships among them. The species could be easily distinguished by two enzyme systems, malate dehydrogenase (MDH) and phosphoglucose isomerase (GPI), although other enzyme combinations were also diagnostic. Genetic similarity index data indicated considerable genetic variability among the 12 species. Isozyme data supported the current taxonomic placement of the investigated species. The terrestrials [Cymbidium goeringii (Rchb. f.) Rchb. f., Cymbidium ensifolium (L.) Swartz, and Cymbidium sinense (Jackson) Wild.], which are all members of the subgenus Jensoa (Rafin.) Seth & Cribb., were the most closely related.