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  • Author or Editor: George L. Hosfield x
  • Journal of the American Society for Horticultural Science x
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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

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

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

Abstract

Nine inbred onion (Allium cepa L.) lines of diverse origin and known horticultural performance were crossed in diallel to measure the extent of heterosis for yield and 6 other traits and to evaluate the types of gene action involved in character expression. Parents and the 36 F1 hybrids were compared at 2 locations (Michigan and Wisconsin) in 1975. Average performance of the parents and hybrids showed good agreement between environments for yield and several other traits. The mean performance of F1 hybrids fell within the range of parents for all characters. Although not always significant, F1’s on the average yielded more, were earlier to mature, had greater bulb weights, more centers, fewer rings, and were less firm than the average of the better parents in crosses. Heterosis was significant and favorable at both locations for yield, maturity, and bulb weight, but unfavorable for centers/bulb. Yield heterosis of the hybrids over the mid- and high parent, respectively, were 39 and 20% at Palmyra, Wisconsin and 27 and 12% at East Lansing, Michigan. In general, high F1 yields were associated with crosses involving high yielding parents. Variances of general combining ability (GCA) predominated for all traits. Small but significant specific combining ability (SCA) effects were noted for maturity, bulb firmness, and % of storage loss.

Open Access

Abstract

A diallel analysis was used to estimate combining ability of several traits in onion (Allium cepa L.) and evaluate the importance of interactions of general combining ability (GCA) and specific combining ability (SCA) with locations and years. All possible crosses among 7 inbred lines of diverse origin and known horticultural performance were tested for 2 years at the same 3 locations for yield, maturity, bulb traits, and storage quality. Highly significant differences among crosses were detected for all traits. The partitioning of among-cross variation showed that all GCA main effects were highly significant, and SCA main effects were significant for all traits but ring thickness. Cross × environment interactions were primarily due to the interactions of GCA effects with environments. The GCA × year interaction was significant for bulb firmness and centers/bulb, and the GCA × location interaction was significant for yield. While first-order interactions involved only GCA effects, all traits showed significant second-order interactions of both GCA and SCA with years and locations. Variance components of GCA were predominant for all characters, and ratios of GCA to SCA ranged from 2:1 for centers/bulb to 13:1 for % of storage loss. Variance components of GCA × environmental interactions at all levels and for all traits were always smaller than those for GCA main-effect components. For the traits maturity and % of storage loss, the SCA × year × location component was larger than the SCA component. Correlations of GCA effects between environments suggested that significant interactions of GCA were sometimes due to a 1) change in rank of effects from environment to environment and 2) a change in rank and change in variance.

Open Access

Three populations of navy bean (Phaseolus vulgaris L.), consisting of recombinant inbred lines, were grown at two locations for 2 years and were used to study canning quality. The traits measured included visual appeal (VIS), texture (TXT), and washed drained mass (WDM). Genotype mean squares were significant for all three traits across populations, although location and year mean squares were higher. We found a positive correlation (r = 0.19 to 0.66) between VIS and TXT and a negative correlation (r = -0.26 to -0.66) between VIS and WDM and between TXT and WDM (r = -0.53 to -0.83) in all three populations. Heritability estimates were calculated for VIS, TXT, and WDM, and these values were moderate to high (0.48 to 0.78). Random amplified polymorphic DNA markers associated with quantitative trait loci (QTL) for the same canning quality traits were identified and studied in each population. Marker-QTL associations were established using the general linear models procedure with significance set at P=0.05. Location and population specificity was common among the marker-QTL associations identified. Coefficient of determination (R2) values for groups of markers used in multiple regression analyses ranged from 0.2 to 0.52 for VIS, 0.11 to 0.38 for TXT, and 0.25 to 0.38 for WDM. Markers were identified that were associated with multiple traits and those associations supported correlations between phenotypic traits. MAS would offer no advantage over phenotypic selection for the improvement of negatively associated traits.

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A knowledge of the relative proportion of additive and nonadditive genetic variances for complex traits in a population forms a basis for studying trait inheritance and can be used as a tool in plant breeding. A North Carolina Design II mating scheme was used to determine the inheritance of cooking time, protein and tannin content, and water absorption among 16 genotypes of dry bean (Phaseolus vulgaris L.) representative of the Andean Center of Domestication. Heritability and the degree of dominance for the traits were also calculated to provide guidelines for adopting breeding strategies for cultivar development. Thirty-two progeny resulted from the matings and these were assigned to two sets of 16 progeny each. Variances due to general combining ability (GCA) and specific combining ability (SCA) were significant for the traits. The GCA was larger in all cases. Narrow-sense heritability for protein, tannin, water absorption, and cooking time averaged 0.88, 0.91, 0.77, and 0.90, respectively. Degree of dominance estimates indicted that the traits were governed by genes with partial dominance except, in one case, tannin had a degree of dominance value of zero, indicating no dominance. The phenotypic correlation (-0.82) between water absorption and cooking time justifies using the water absorption trait as an indirect selection method for cooking time. With regard to parent selection in crosses, significant differences between GCA females and GCA males suggested cytoplasmic influences on trait expression. Hence, the way a parent is used in a cross (i.e., as female or male) will offset trait segregation. Using fast-cooking bean cultivars in conjunction with fuel-efficient cooking methods may be the best strategy to conserve fuelwood and help reduce the rate of deforestation in East and Central Africa.

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Three common bean (Phaseolus vulgaris L.) seedcoat color (or glossiness) genotypes, differing from each other by a single substitution at a seedcoat locus, were analyzed for presence and concentration of three anthocyanins: delphinidin 3-O-glucoside, petunidin 3-O-glucoside, and malvidin 3-O-glucoside. The three anthocyanins were present in Florida common bean breeding line 5-593 (P C J G B V Asp), matte black (P C J G B V asp), and dark brown violet (P C J G b V Asp), but the amounts varied greatly depending on the genotype. Dark brown violet had 19% of the total anthocyanin content when compared to 5-593, whereas matte black had amounts intermediate between the two other genotypes. The B gene acts to regulate the production of precursors of anthocyanins in the seedcoat color pathway above the level of dihydrokaempferol formation, perhaps at the chalcone synthase or chalcone isomerase steps in the biosynthetic pathway. We hypothesize that B regulates simultaneously the flavonoid (color) and isoflavonoid (resistance) pathways. The I gene for resistance to bean common mosaic virus (BCMV) is known to be linked closely to B. It is therefore hypothesized that the I gene function may be to respond to BCMV infection by dramatically increasing (over a low constituitive level) production in the 5-dehydroxy isoflavonoid pathway, which leads to synthesis of the major phytoalexin, phaseollin, for resistance to BCMV. Alternatively, the B and I genes may be allelic. The Asp gene affects seedcoat glossiness by means of a structural change to the seedcoat. We demonstrate that Asp in the recessive condition (asp/asp) changes the size and shape of the palisade cells of the seedcoat epidermis, making them significantly smaller than either 5-593 or dark brown violet. Asp, therefore, limits the amounts of anthocyanins in the seedcoat by reducing the size of palisade cells.

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Canning quality of dry bean (Phaseolus vulgaris L.), of which the degree of splitting (SPLT) and overall appearance (APP) of canned beans are major components, is a complex trait that exhibits quantitative inheritance. The objectives of this study were to identify major genes that affect APP and SPLT in kidney bean, and map the location of these loci to the integrated core map of common bean. The analysis was performed using random amplified polymorphic DNA (RAPD) markers and two populations of kidney bean, consisting of 75 and 73 recombinant inbred lines (RILs), respectively. The two populations—`Montcalm' × `California Dark Red Kidney 82' and `Montcalm' × `California Early Light Red Kidney'—were planted in six year-location combinations in Michigan, Minnesota and North Dakota from 1996 to 1999. Correlations between APP and SPLT were high (0.91 to 0.97). Heritability estimates for APP and SPLT ranged from 0.83 to 0.85 in the two populations. Major genes for these traits were identified on two linkage groups. The first QTL, associated with seven RAPD markers, was putatively mapped to the B8 linkage group of the core bean linkage map. Desirable canning quality appeared to be derived from Montcalm at this locus. The second QTL, associated with four markers, appeared to be derived from the California parents. The second linkage group was not assigned to a linkage group in the core map. Population and environment-specificity were observed for the markers identified.

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