The relationship between malate dehydrogenase (MDH) isozyme genotype and plant vigor in peach [Prunus persica (L.) Batsch] was examined in two F2 populations (selfed `Belle of Georgia' and `Cresthaven') segregating at the Mdh1 locus. Total progeny examined were 1610 and 998 in the `Belle of Georgia' and `Cresthaven' populations, respectively. In both populations, plant vigor (as defined by total height and trunk caliper after 1 year of growth) was significantly less in Mdh1-1/Mdh1-1 homozygotes. Homozygous Mdh1-2/Mdh1-2 individuals showed the greatest vigor, and were significantly different in vigor from Mdh1-1/Mdh1-1 homozygotes in both populations and from Mdh1-1/Mdh1-2 heterozygotes in the `Belle of Georgia' population. A significant deviation from the expected 1 Mdh1-1/Mdh1-1: 2 Mdh1-1/Mdh1-1: 1 Mdh1-2/Mdh1-2 ratio was observed in the `Belle of Georgia' population, suggesting moderate lethality of homozygous Mdh1-1/Mdh1-1 genotypes.
Dennis J. Werner and Dana F. Moxley
Cyrus Samimy and James N. Cummins
We thank C.S.'s 14-year-old son, Sawson, for drawing the 6PGD isozyme banding patterns by computer. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be
Mark S. Strefeler, Elizabeth Darmo, Roger L. Becker, and Elizabeth J. Katovich
helped with lab work, and Peter Ascher and Neil Anderson provided plant materials and helped interpret the isozyme gels. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore
Chang-Xia Du, Huai-Fu Fan, Shi-Rong Guo, and Takafumi Tezuka
. Cucumber is one of the most important vegetables worldwide. It is highly sensitive to salinity, especially during germination and in the early stages of development ( Baysal and Tipirdamaz, 2007 ). The effect of SPD on isozymes of antioxidant enzymes (SOD
Jing Tian, Li-Ping Wang, Yan-Juan Yang, Jin Sun, and Shi-Rong Guo
and isozyme expression of antioxidant enzymes in cucumber seedlings and to assess the possible protective or reversible effect of exogenous Spd application from the oxidative damage caused by high-temperature stress. Materials and Methods Plant
Paul D. Mangum and Ellen B. Peffley
Horizontal starch gel electrophoresis was used to study the mode of inheritance of isozyme phenotypes of four enzyme systems (ADH, 6-PGDH, PGM, and SKDH) in Allium cepa L. and A. fistulosum L. by monitoring segregations in backcross and F2 progeny. Segregation for most of the polymorphisms fit the expected Mendelian ratios as tested by the chi-square statistic. Three new isozyme loci were defined for onion. 6-phosphogluconate dehydrogenase was dimeric in structure, with two alleles present at the first locus, while a second locus was monomorphic. Shikimate dehydrogenase was monomeric with two alleles.
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.
P. Obara-Okeyo, Kouei Fujii, and Shunji Kako
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.
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.
W. Sun and J. L. Brewbaker
The Leguminous Leucaena including 15 species, of which several have become pantropical as fodder, fuelwood, shade and ornamental trees. 160 collections of 12 Leucaena species, including 3 tetraploids and 9 diploids, were analyzed for six isozyme systems. Extensive inter and intraspecific variability was detected using cotyledon tissues. The uniformity of isozymic expression in 80 collections of the “common leucaena” from all over the world supported the hypothesis that it is a single self-pollinated variety. It was first distributed to the Philippines from Mexico in late 1500s, then spread worldwide. ACO polymorphism appeared to be controlled by three loci ACO1, ACO2, ACO3 and IDH by two loci IDH1, IDH2 in L. lanceolata. Peroxidase polymorphism was early shown to involve 4 loci, PX1-PX4. Polymorphism in these loci was applied to clarify phylogeny of the Leucaena ssp. and hybrids (>60 made in Hawaii), that are growing in the Waimanalo Sta. of UH.