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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.
Abstract
Enzyme heterogeneity in relatively pure extracts has been demonstrated for many plants (44), particularly through the application of gel electrophoresis techniques. Isoenzyme heterogeneity was discerned first in esterase and lactate dehydrogenase (27), and implications of this heterogeneity have excited interest in many areas of the biological sciences. We will discuss in this paper some areas in the horticultural sciences in which protein electrophoresis appears to have significant practical and basic research applications.
Abstract
Peroxidases from certain Musa spp. isolated using horizontal Polyacrylamide gel electrophoresis revealed 4 major zones of activity and 15 separate peroxidase bands. Good agreement was obtained among cultivars of different ploidy groups when composite zymograms were constructed from gel data and compared to a current taxonomic classification. Three clones of unknown origin were genotypically classified as ‘Hapai’ (AA); ‘Tuu Gia’ (AA); and ‘Eslesno’ (AAB).
Abstract
The use of gel electrophoresis of different isozyme systems was investigated as a possible tool to identify Anthurium andraeanum cultivars. Procedures were developed to extract active enzymes from anthurium leaves. Clear zymograms were obtained from only one of three extraction methods examined. This method consisted of grinding the leaf tissue in liquid nitrogen and then adding to the ground tissue a buffer containing a phenoloxidase inhibitor, reducing agents, and polyvinylpolypyrrolidone (PVPP). The identification of seven anthurium cultivars was undertaken using seven enzyme systems. Bands were observed in four of these systems; glutamate-oxaloacetate transaminase (GOT), malate dehydrogenase (MDH), peroxidase (Px), and phosphoglucose isomerase (PGI). All seven cultivars were characterized by the combined data of Px, MDH, and PGI.
Resistance to Puccinia sorghi Schwein. based on the Rp1-D gene has been used successfully in North America for the past 15 years to control common rust on sweet corn (Zea mays L.). The objective of this preliminary research was to examine rust reactions of Rp-hybrids grown for processing in the midwestern United States against biotypes of P. sorghi virulent against Rp1-D. In Sept. 1999, isolates of P. sorghi virulent on corn with the Rp1-D gene were collected throughout the midwestern United States. Rust reactions of 41 Rp-resistant, processing sweet corn hybrids and nine non-Rp hybrids were evaluated during the 1999-2000 season in Argentina, Hawaii, Mexico, and South Africa, where populations of P. sorghi are virulent against Rp1-D. Sporulating uredinia were observed on all hybrids in all locations. Although rust reactions varied among locations, mean standardized scores of nine non-Rp hybrids that were included in the trial as controls ranked nearly the same as in previous trials. Thirteen hybrids with standardized scores above 0.25 were more susceptible than the hybrid with the lowest mean rust rating, `Green Giant Code 27'. Thirty-two hybrids were intermediate in reaction to P. sorghi virulent against Rp1-D. Reactions were moderately resistant for nine hybrids with mean standardized scores below -0.50, including two moderately resistant, non-Rp hybrids (`GG Code 27' and `GG Code 6') that were included as controls. Additional trials are necessary to confirm reactions of these hybrids. If the Rp-hybrids that were moderately susceptible or susceptible in this trial are infected by P. sorghi virulent against Rp1-D, secondary inoculum will be abundant and infection will be severe if the weather is wet.