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Abstract
The abstract for the paper, “Effect of the Fruit-ripening Mutant Genes rin and nor on the Flavor of Tomato Fruit” by E. Kopeliovitch, Y. Mizrahi, H. D. Rabinowitch, and N. Kedar [J. Amer. Soc. Hort. Sci. 107(3):361–364. 1982.], contains several errors. The correct version of the abstract is as follows: Organoleptic tests of the nonripening tomato mutants rin and nor and their F1 hybrids with the normal-fruit-bearing cultivar ‘Rutgers’ indicated that fruits of the rin heterozygous plants (rin/+) were slightly inferior and that those of heterozygote nor (nor/+) were distinctly inferior in flavor to fruits of the normal genotype (+/+), all sampled 3–5 days after ethylene and CO2 evolution rates attained maximum levels. The flavor of fruits of the double heterozygotes rin/+, nor/+ was poorer than either of the 2 single-gene heterozygotes, while fruits of both homozygous plants, nor/nor and rin/rin, were unpalatable. Analyses of pH, titratable acidity, total soluble solids, and reducing sugars did not indicate that any of these parameters are responsible for the inferior flavor of the genotypes containing the nonripening genes. Comparisons of reciprocal crosses provided no evidence of cytoplasmic inheritance of fruit flavor.
Abstract
Organoleptic tests of the non-ripening tomato mutants rin and nor and their F1 hybrids with the normal-fruit-bearing cultivar ‘Rutgers’ indicated that fruits of the rin heterozygous plants (rin/+) were slightly inferior and that those of inferior in flavor to fruits of the normal genotype (+/+), all sampled 3–5 days after ethylene and CO2 evolution rates attained maximum levels. The flavor of fruits of the double heterozygote nor heterozygotes (nor/+) were distinctly rin/+, nor/+ was poorer than either of the 2 single-gene heterozygotes, while fruits of both homozygous plants, nor/nor and rin/rin, were unpalatable. Analyses of pH, titratable acidity, total soluble solids, and reducing sugars did not indicate that any of these parameters is responsible for the inferior flavor of the genotypes containing the non-ripening genes. Comparisons of reciprocal crosses provided no evidence of cytoplasmic inheritance of fruit flavor.
Abstract
A range of tomato (Lycopersicon esculentum Mill.) cultivars was examined for changes during ripening in firmness, endopolygalacturonase (PG) activity and the molecular forms of polygalacturonase, Ca concentration, and the extractability of the Ca. Firm cultivars were firmer than the soft cultivars throughout ripening, and generally they contained less PG activity at each stage examined. In all cultivars, PG was predominately or entirely in the high molecular weight form (PG1) early in ripening, with the PG2 forms being increasingly prominent as ripening progressed. Differences in firmness were established while PG1 was the predominant PG. Uronic acid polymers in isolated cell walls were degraded rapidly by endogenous PG when citrate was present to complex Ca. In the presence of sufficient citrate, cell wall uronic acids of a firm and soft cultivar were equally susceptible to hydrolysis, suggesting that differences in the digestion of the walls by PG were dependent upon differences in Ca content or distribution. However, neither total, water, nor saline-extractable Ca showed consistent correlations with fruit firmness, and they also showed no progressive change during ripening.