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  • Author or Editor: George L. Hosfield x
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Seed coat color in dry bean (Phaseolus vulgaris L.) is determined by the presence or absence of tannins, flavonoids, and anthocyanins. Black beans contain three main anthocyanins that are responsible for their black seed coat color: delphinidin 3-O-glucoside, petunidin 3-O-glucoside, and malvidin 3-O-glucoside. Leaching of anthocyanins occurs in many black bean genotypes during thermal processing (i.e., blanching and cooking). Black beans that lose their dark color after processing are unacceptable to the industry. Since the marketability of black beans can be adversely affected by thermal processing, an experiment was conducted to ascertain whether pigment leaching was due to qualitative or quantitative changes in anthocyanins during processing. Four black bean genotypes that showed differential leaching of color were investigated. `Harblack' retains most of its black color after processing while `Raven' loses most of its color. `Black Magic' and `Black Jack' are intermediate between `Harblack' and `Raven' in processed color. Bean samples (119 ± 1.5 g) of the four genotypes were thermally processed in 100 x 75-mm tin cans in a pilot laboratory. Seed coats were removed from the cooked beans, freeze-dried, and placed in solutions of formic 10 acid: 65 water: 25 methanol to extract anthocyanins. The extracts were analyzed by HPLC. Although all genotypes retained some color, there were no detectable anthocyanins in seed coats of the cooked beans. In a second experiment, raw beans of each genotype were boiled in distilled water for 15 minutes. All four genotypes lost color during boiling, but `Harblack' retained most of its color and had a five-fold higher concentration of the three anthocyanins than did the other genotypes. `Harblack' may retain color better than other black beans because of physical characteristics of the seed coat.

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Genetic and environmental interactions for bean cooking time, water absorption, and protein content were estimated with 10 dry bean (Phaseolus vulgaris L.) cultivars grown at three locations in Rwanda, Africa, during five consecutive harvests. The genotypic variance component was larger than genotype × environment variance components for the cooking time index and percent water absorption. No significant genotypic effect was observed for seed protein content. The phenotypic correlation (-0.37) between the cooking time index and percent water absorption was not strong enough to justify the use of water absorption as an indirect selection method for cooking time. The most efficient allocation of resources to evaluate the cooking time of common bean cultivars with a 25-pin bar-drop cooker was four field replications over two harvests at two locations. Water absorption was evaluated most efficiently with four field replications over two harvests at a single location.

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Abstract

The mutant trait glabrous seedstalk was observed in carrot (Daucus carota L.) inbred W93 and, in crosses with pubescent inbred MSU 1558, was found to be controlled by a single recessive gene, gls. Cytoplasmic effects on the expression of the character were not detected. Glabrous seedstalk has practical application as a genetic marker to detect outcrosses in hybrid carrot seed production fields.

Open Access

Abstract

Roots from 8 advanced generation breeding lines of carrot (Daucus carota L.) repeatedly selected for high or low total soluble solids content, and 2 selections of Tmperator 58', one with high and one with low soluble solids, were evaluated for perceived sweetness and eating quality by taste panels. Most taste evaluations were made using the Quantitative Descriptive Analysis method. Two breeding lines, 5158 and 5164, had high levels of solids (X's averaging 10.4 and 10.8% respectively) but were downgraded in perceived sweetness in panel evaluations. The ranking of the other lines according to their mean preference scores for perceived sweetness was related to total soluble solids content. Bitter taste and harsh flavor characteristics were associated with 5158 and 5164. No perceived sensory differences were found between the high and low selections of Imperator 58 by a technological panel. A consumer preference taste panel, however, showed a slight preference for eating carrots from the high solids selection. The background constituents of carrot flavor appear to play an important role in the perception of sweetness at all levels of soluble solids.

Open Access

Seedcoat color in dry bean (Phaseolus vulgaris L.) is associated with physical and chemical characteristics of the seed. Allelic substitutions at a single or several seedcoat color determining loci were found to influence several seed characteristics. Whole bean fresh and dry mass and the ratios of seedcoat mass to whole bean dry mass differed significantly among nine seedcoat color genotypes. Dry mass of seedcoat increased significantly as total bean dry mass increased. Genotypes VOO59 and VO400 had the largest masses of whole dry bean, lowest ratios of seedcoat to whole bean dry weight, and the lightest colored seedcoats of the nine genotypes. In general, compared to VOO59 and VO400, the smaller seeded and darkly colored genotypes had significantly higher ratios of seedcoat to whole bean dry masses. Differences among color genotypes for seed physical characteristics are useful to estimate the fresh mass of seed needed to effectively extract seedcoat flavonoid color compounds.

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Ninety-eight percent of the navy beans (Phaseolus vulgaris) grown in the US are processed. Thus, new cultivars considered for release must meet industry standards. Canning quality behaves as a classical QTL which precludes its selection and evaluation in early generations. Such delays add a measure of inefficiency to a breeding program. Indirect selection for canning quality using molecular markers could increase efficiency. RAPD markers are more useful than RFLP's, in Phaseolus, due to a simpler protocol and a higher level of polymorphism within genetically related cultivars. Three populations of RIL's, derived from crosses between cultivars with standard and sub-standard canning quality, were screened to identify markers associated with canning quality. Material for evaluation was grown at two locations, in three replications and processed, in the Food Science Processing Lab, following industry standards. Quality traits measured were: processed texture, color and appearance. Associations of putative markers with canning quality were identified using ANOVA and Mapmaker programs

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Dry bean (Phaseolus vulgaris L.) seed coat color is determined by the presence and relative amounts of phenolics, flavonoids, and anthocyanins present in the lumen of epidermal cells. Some of these chemicals may interact with proteins of the cotyledon to form complexes that render beans hard to cook and digest. Eight genetic loci control seed pigment chemistry. When all eight loci are dominant, a shiny black seed coat results, but recessive substitutions at one or more loci yield colors ranging from white, yellow, and brown to dark violet. In order to relate Mendelian genes for seed coat color to the pigments formed, we studied eight genetic stocks that had recessive substitutions at one or more color-determining loci in an otherwise all-dominant genetic background. Seed coat from each genotype was extracted exhaustively with hexane, EtOAc, MeOH, MeOH:H2O 1:1, and H2O 100%. Silica gel thin-layer chromatography (TLC) (solvent system CHCl3:MeOH 4:1) analysis of the MeOH fraction showed that one genotype had no phenolic compounds and two had only simple phenols. Once flavonol glycoside was present in relatively large amounts in four of the genotypes, but absent in genotypes with anthocyanins. Cellulose TLC (2-dimensional, Butanol:Acetic Acid:H2O 4:1:5 first dimension, 1% HCl second dimension) of the anthocyanin-containing genotypes showed that the presence of one flavonol and three anthocyanidin-3-glycosides (UV spot color and color shift with NH3). The relative importance of the seed coat chemicals in digestibility and their antioxidant will also be discussed.

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Three dry bean (Phaseolus vulgaris L.) genotypes differing in seedcoat color, mineral brown (P C D J G B v), yellow brown (P C D J G b v), and pale greenish yellow (P C D J g b v), were analyzed phytochemically. Kaempferol 3-O-β-d-glucoside (astragalin) was isolated and identified by nuclear magnetic resonance spectroscopy from all three genotypes, and was the main flavonoid monomer present. Flavonoid polymers (condensed tannins) were detected by thin layer chromatography, but anthocyanins were not detected in the three genotypes. High pressure liquid chromatography analyses indicated that astragalin was present at similar concentrations in pale greenish yellow and mineral brown genotypes, but was significantly lower in yellow brown. Presently, we do not know the functions of the G and B color genes, although the presence of astragalin in the three genotypes studied indicates these genes do not appear to act in a qualitative manner with regard to astragalin production, but may control the amount of astragalin present. Subtle differences in color between these genotypes may be due to the amount and type of tannins which have secondarily polymerized with phenolics and flavonoid monomers.

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Abstract

The diallel cross technique was used to evaluate the performance of onion (Allium cepa L.) inbred lines in F1 combinations and to estimate combining ability of several traits. All possible crosses, including reciprocals, among 10 inbred lines of diverse origin and known horticultural performance were tested at 3 locations in 1973. Cytoplasmic male-sterility was used to insure that all seed from maternal plants was hybrid. Cross variances were highly significant for all traits at all locations. General combining ability effects accounted for most of these differences. Specific combining ability effects were significant at all locations for yield, weight/bulb, firmness, and percent of storage loss. In all instances variance components of general combining ability were larger than those of specific combining ability. Specific rankings of the best and poorest lines for the traits measured according to the effects of their general combining ability were not identical at each location, but the same inbreds were generally in the same positive or negative grouping. Inbreds M728 and M2399 transmitted substantial yield and bulb weight to their progeny, while la163 consistently depressed these traits in the F1's. These results confirm the contribution that inbreds M728, M2399, and la163 make to a hybrid. Significant mean squares for reciprocal effects were apparent at all locations for only yield and maturity. Maternal effects per se influenced reciprocal variation, but were, generally, less important than nonmaternal reciprocal causes.

Open Access