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
Cyrus Samimy and James N. Cummins
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
Roger G. Fuentes-Granados and Mark P. Widrlechner
This study was conducted to determine the inheritance of anthocyanin production and of malate dehydrogenase banding patterns in Agastache rugosa. Results of the study support the hypothesis that anthocyanin production is controlled by a single dominant gene, designated as A, for anthocyanin production. The Mdh-3 banding patterns are controlled by two alleles, each of which associated with a two-banded phenotype. A monomeric quaternary structure of MDH, which is rather atypical among plant species, can be inferred from the results. No linkage was found between the loci governing anthocyanin production and Mdh-3 banding patterns. This is the first report of heritable variability in A. rugosa.
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.
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.
Janice L. Stephens and Harrison G. Hughes
Isozyme analysis was used to characterize and identify 24 species, hybrids, and color variants of Alstroemeria, two plants of Leontochir ovallei, and one plant of Bomarea. A single technique was developed for the extraction of seven enzyme systems (PGM, PGI, 6-PGD, EST, ME, AAT, and LAP) that exhibited a high level of polymorphism. Between 11 and 18 of the species and hybrids could be identified uniquely for each of the first six enzyme systems. The final system, LAP, was tested on only 11 species and hybrids, and nine different patterns were identified. Using only three of the seven enzyme systems, it was possible to uniquely identify all of the species and hybrids investigated.
Bruce D. Mowrey and Dennis J. Werner
To determine the earliest developmental stage at which isozyme screening could be accomplished, 10 isozyme systems were examined in peach [Prunus persica (L.) Batsch] for differential expression during development. Differences in isozyme expression based on stage of development were detected in nine systems. The earliest stage for complete screening of most isozymes examined is in l-month-old seedlings. The significance of these results relative to genetic mapping is discussed.
Thomas S. Brettin and Ken C. Sink
We have used isozyme techniques (SGE) to assess variation and begin construction of a genetic map of the Asparagus officinalis genome. Isozyme extraction buffers, electrophoretic buffer systems, and isozyme stability during storage were evaluated. Isozyme expression under different environmental conditions was also examined. Thirty-four enzymes were evaluated for their usefulness as genetic markers in A. officinalis. Of these 34, 13 had sufficient activity and resolution on the gels for isozyme analysis. Of the 13 enzyme systems resolved, polymorphisms were observed in aconitase, endopeptidase, malate dehydrogenase, phosphoglucomutase, and shikimate dehydrogenase. Segregation of putative alleles is presented for ACON, END, MDH, PGM and SKDH isozymes. Co-segregation data showed linkage between a SKDH locus and a PGM locus. The isozyme analysis also included Asparagus densiflorus `Sprengeri' and revealed that aspartate aminotransaminase, endopeptidase, and triosephosphate isomerase would be potentially useful for verification of cell fusion products between the two species.