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
A. Hashemi and A. Estilai
Leaf extracts of diploid guayule were analyzed for phosphoglucomutase (PGM, EC 184.108.40.206) and menadione reductase (MNR, EC 220.127.116.11) isozymes by starch gel electrophoresis. Banding patterns of hybrids indicated that PGM is monomeric and MNR tetrameric in structure. Two codominant alleles were identified at each of two Pgm loci, designated as Pgm-2 and Pgm-3. Two codominant alleles were observed at Mnr-2; MNR-1 was monomorphic in the Parthenium argentatum genotypes analyzed.
James J. Tobolski and Ricky D. Kemery
Dormant bud tissue from two or more trees representing 18 red maple (Acer rubrum L.) cultivars was subjected to isozyme analyses using starch-gel electrophoresis. Polymorphic enzymes resolved were alcohol dehydrogenase, peroxidase, phosphoglucase isomerase, glutamate oxaloacetate transaminase, leucine aminopeptidase, acid phosphatase, and malic dehydrogenase. An enzyme pattern or combination of patterns was useful in identifying individual cultivars, these included: `Autumn Blaze', `Autumn Flame', `Bowhall', `Celebration', `Columnare', `Curtis', `Doric', `Firedance', `Gerling', Y.J. Drake', `Morgan', `Northwood', `Scarlet Sentinel', `Schlesingeri', and `Tilford'. `Armstrong', `October Glory', and `Red Sunset' could not be distinguished from each other on the basis of enzymes examined in this study.
Robert D. Marquard and Charlotte R. Chan
Forty-five crabapple (Malus spp.) cultivars were evaluated for 16 isozyme 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, aspartate aminotransferase, malate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucoisomerase, and shikimate dehydrogenase. Each enzyme system produced one well-resolved polymorphic region except for 6-phosphogluconate dehydrogenase, which produced two. Most crabapple selections could be identified when all six enzymes were evaluated. Alcohol dehydrogenase had the most diagnostic banding patterns useful for cultivar identification.
Roger G. Fuentes-Granados, Mark P. Widrlechner, and Lester A. Wilson
The inheritance of five allozymes was studied in anise hyssop (Agastache foeniculum) by analyzing the progeny of controlled crosses. The loci studied [Cat-1, Got-2, Pgm-2, Tpi-1, and Tpi-2] were scored by using starch gel electrophoresis. Segregation analyses of families polymorphic at each of these loci support the following hypotheses: Cat-1 is controlled by a single gene with codominant alleles; Got-2 is controlled by a single gene with codominant alleles coding for dimeric protein products; Pgm-2 is controlled by a single gene with codominant alleles coding for monomeric proteins; and Tpi-1 and Tpi-2 are each controlled by a single gene with codominant alleles coding dimeric protein products. Distorted segregation ratios were observed in some families segregating for Got-2 and Pgm-2. No linkages were detected among any of the cosegregating loci.
J. Carapetian, A. Estilai, and A. Hashemi
To detect isozyme variation, leaf extracts of more than 460 plants from 20 safflower (Carthamus tinctorius L.) entries with diverse geographic origins were analyzed. Entries included seven Iranian spring-type selections, eight Iranian late rosette winter-type selections, four U.S. cultivars, and one Indian introduction. Starch gel electrophoresis produced distinct and repeatable banding patterns for nine of the 15 enzymes assayed. Five of these enzymes, aldolase (ALD, EC 18.104.22.168), isocitrate dehydrogenase (IDH, EC 22.214.171.124), malate dehydrogenase (MDH, EC 126.96.36.199), malic enzyme (ME, EC 188.8.131.52), and phosphoglucomutase (PGM, EC 184.108.40.206), were monomorphic. Menadione reductase (MR, EC 220.127.116.11), 6-phosphogluconate dehydrogenase (6-PGDH, EC 18.104.22.168), phosphoglucoisomerase (PGI, EC 22.214.171.124), and triosephosphate isomerase (TPI, EC 126.96.36.199) were polymorphic. 6-PGDH revealed an invariable cathodal and a variable anodal zone of activity. Crosses were made between appropriate parents and F1, BC1, and F2 progenies were generated for segregation analyses. Two multibanded phenotypes that bred true were observed for MR. Crosses between these types produced 7-banded F1 plants. F2 progenies segregated in parental and hybrid phenotypes in the expected 1:2:1 ratio. Both PGI and TPI showed one monomorphic and one polymorphic zone of activity. Segregation data indicated that Pgi-2 and Tpi-1 are monogenic and controlled by two codominant F and S alleles. The observation of the parental bands plus an intermediate band with a higher intensity in hybrid plants suggested that PGI and TPI act as dimeric enzymes in safflower. Isozyme genetic markers described in this study are useful tools for identification of hybrid individuals in this predominantly inbreeding species.
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.
J.C. Cousineau, A.K. Anderson, H.A. Daubeny, and D.J. Donnelly
Isoenzyme staining of horizontal starch gels was used to characterize 23 cultivars and three advanced selections of red raspberry (Rubus idaeus L.). The genotypes were separable using the enzymes malate dehydrogenase, phosphoglucoisomerase, phosphoglucomutase, and triose phosphate isomerase. In addition, staining for isocitrate dehydrogenase and shikimate dehydrogenase revealed polymorphisms in some cultivars. By combining these results with those obtained for 78 previously tested cultivars, 75 of the 104 (72%) genotypes tested were uniquely characterized using the six isoenzymes.
J. Tous, C. Olarte, M.J. Truco, and P. Arús
The variability of isozymes in nine enzyme systems was studied in 25 carob (Ceratonia siliqua L.) cultivars using starch gel electrophoresis of leaf extracts. Five enzymes (phosphoglucomutase, phosphoglucoisomerase, aspartate aminotransferase, shikimic dehydrogenase, and aconitase) were polymorphic, making it possible for the 25 cultivars to be classified into eight phenotype categories.
Larry S. Kennedy and Paul G. Thompson
The enzymes alcohol dehydrogenase, diaphorase, esterase, glutamate dehydrogenase, glucosephosphate isomerase, isocitrate dehydrogenase, malate dehydrogenase, malic enzyme, 6-phosphogluconate dehydrogenase, phosphoglucomutase, shikimate dehydrogenase, and xanthine dehydrogenase were analyzed by starch gel electrophoresis of leaf tissue from nine sweetpotato [Ipomoea batatas (L.) Lam.] cultivars. Bands of most enzymes were well-defined. Polymorphisms were found in nine enzymes, and cultivars were identified by comparing polymorphisms.