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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.
Somatic fusion hybrids created between tomato and Solanum ochranthum, a wild nontuber-bearing diploid species that is genetically isolated from tomato, were evaluated in an effort to introgress traits from S. ochranthum into tomato. Pollen stainability and pollen tube growth examination demonstrated that little or no viable pollen was present in tetraploid and hexaploid fusion hybrids. Aneuploidy was noted in a small percentage of these hybrids. Use of tetraploid and hexaploid fusion hybrids as female parents in backcrosses to diploid and tetraploid tomato was studied. Chemical treatments that induce either chromosomal recombination or reduction may be advantageous for overcoming difficulties in introgression of these wide hybrids into tomato.
Incorporation of genes from wild species has been a major contributor to tomato improvement in recent years. Solanum ochranthum, a woody non-tuber bearing species, is a potential source of resistance against tomato diseases and insect pests but is genetically isolated from tomato. Somatic hybridization methods were developed to facilitate the use of S. ochranthum for tomato germplasm improvement. Leaf mesophyll protoplasts of S. ochranthum and a Lycopersicon esculentum hybrid were chemically fused with polyethylene glycol. The protoplasts were initially cultured in Shepard's CL, a MS based medium, containing 1 mg·1-1 NAA, 0.5 mg·1-1 BAP and 0.5 mg·1-1 2,4-D. Hybrid regenerants and regenerants of the L. esculentum parent were recovered; S. ochranthum did not regenerate. Hybridity was established by morphological characters, peroxidase isozyme and RAPD markers. Use of these somatic hybrids for tomato improvement was evaluated.