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Opaque globules formed on bean callus induced on primary leaf explants cultured on induction media (IM) containing 10 to 30 mg/l 2,4-D. Calli with globules produce structures reminiscent of somatic embryos (embryoids) after subculture in a liquid challenge medium (LCM). Calli maintained on IM for 2, 3, 4, and 5 weeks produced significantly more (26 to 34/callus) embryoids in LCM than calli maintained on IM for one week (12/callus). Well developed embryoids only occurred after calli were subculture in liquid B5 with 0.1 to 1.0 mg/l IBA. Calli subculture in LCM with > 10 mg/l IBA turned necrotic and died. Embryoids produced in B5 with 2,4-D and NAA (0.1 to 1.0 mg/l) proliferated roots and formed “frosty” appearing structures, respectively. No differences were detected in number or quality of embryoids produced in LCM from callus maintained on IM in continuous light or darkness regardless of the induction time. Ethylene accumulation in IM cultures inhibited globule formation.
Abstract
Seedlings of bean, (Phaseolus vulgaris L.), were separated into scions and rootstocks using a V-shaped razor blade secured in a cutting block and mounted on a pair of electrician's pliers. Precise cuts could be made rapidly and easily, and the use of a hair clip eliminated the need for wrapping and unwrapping the graft. Grafted plants were transplanted in the greenhouse and to the field with a high degree of success. Components of seed yield, plant weight, and harvest index (ratio of seed weight to dry weight of aerial portion of plant) were affected by grafting on either the same strain or other strains used as rootstocks.
Abstract
Food-quality comparisons between tropically adapted genotypes of dry bean (Phaseolus vulgaris L.) and accessions from domestic breeding agencies showed there is sufficient variability in important nutritional and canning traits among tropical beans to justify their use in temperate-climate breeding programs. Specifically, tropical bean germplasm may be of use to transfer stress tolerance and lodging resistance to commercially acceptable genotypes while the breeder is simultaneously breeding to maintain or improve nutritional composition and canning quality. Seed of 35 bean accessions representing plant introductions, breeding lines, and cultivars were screened for proximate chemical composition, yield, and several horticultural characters. Seventeen of these accessions, including several commercial dry bean cultivars, were selected for canning evaluations. Beans were adjusted to 16% moisture before soaking and processing. Soaked and processed beans were evaluated for water uptake, texture (with a Kramer Shear Press), and general canning quality. Protein content was highest in domestically adapted beans (31%) and lowest in the nonblack tropical array of genotypes (22%). Tropical beans showed a greater tendency to clump in the can after cooking. This indicates excessive breakdown of tropical beans during thermal processing. Nonsignificant correlation coefficients indicated that textural differences and soaking properties of the beans were not associated; however, textural differences were correlated with the final moisture percentage in processed tropically adapted beans. Several tropical genotypes were much firmer or much softer after cooking than ‘Sanilac’, which is considered the industry standard for making canning comparisons. Further evaluation of texture by examining Kramer Shear Press tracings showed that textural differences among genotypes could be broken down into a configuration showing a large shear force component, and a curve characterized by mostly compression. The curve types appeared to be a characteristic of the genotype rather than of seed-coat color, size of bean, or final moisture percentage.
Abstract
We compared 9 dry bean (Phaseolus vulgaris L.) strains characterized by the following architectures for seed filling, yield, and components of yield: small bush, tall erect bush, classic II, and architype. Small and tall erect bush are determinate in growth habit; classic II is indeterminate and produces a short vine. Architype is erect, contains 2–4 branches angled acutely upward, grows to about 75 cm, terminates in a short vine, and does not lodge at maturity. Seed dry weight vs. days after 50% flowering data were fit to a cubic polynomial to calculate the rate and duration of seed filling. Small bush produced the greatest pods/m2 of the groups, but pod set was offset by a high percentage of shriveling and seed abortion. The architype outyielded the tall erect and small bush groups by 34 and 45 %, respectively, which was due to a greater number of seeds/pod, seeds/m2, and heavier seeds. The heavy seeds of the architype compared to the bush appeared to be due to a longer filling duration, because linear seed filling rates were similar. The architype filling duration was 11.3 days compared to 5.7 and 7.0 days for small and tall erect bush, respectively. The longer architype filling duration may be associated with its ability to prolong the duration of photosynthesis. The 17% yield increase of the architype over classic II was due to improved lodging resistance through a modification of the morphology by reducing branches and narrowing the plant canopy.
Abstract
The yields and physico-chemical seed traits related to food quality of 25 strains of dry beans (Phaseolus vulgaris L.) representative of the Black Turtle Soup commercial class were evaluated for 3 seasons. The strains differed significantly over seasons for washed drained weight, textural properties, and surface color characteristics of cooked seeds. All the other traits were nonsignificant in the combined analysis. Trait expression was strongly influenced by genotype × season interactions. Spearman's coefficient of rank correlation between pairs of years indicated that the interactions were due primarily to inconsistent strain rankings from year-to-year. The season and genotype × season variance component estimates for yield, soaking, and several cooked bean traits were larger than the genotypic component, indicating that seasonal effects predominated over genotypic effects. These results suggested that several years of testing are needed to assess strain performance accurately for food quality. The contribution made by each strain to the genotype × season variance component was ascertained by calculating a “stability variance” statistic. Based on this statistic, strains were found to differ in their genetic potential to respond to varying environments. Several genotypes were phenotypically stable for most traits. Strain no. 23 (CIAT pedigree FF 4-13-M-M-M-M), which had good yield (2.8 MT/ha) and protein percentage (27.7%) and favorable culinary quality, was of particular interest.
Culinary quality in dry bean (Phaseolus vulgaris L.) depends on attributes of seeds prevailing at harvest and is determined by the genetic architecture of cultivars and by unpredictable environmental factors. Variation among genotypes for culinary quality has been shown to be heritable; however, the efficacy of selection depends on a knowledge of the genetic control of the measured traits. A diallel mating design was used to estimate the combining ability of parents and determine the inheritance of nine culinary quality traits important to processors and consumers. Genetic variability among eight parents, 56 F2, and 56 F3 progenies was confirmed by significant mean squares from analyses of variance. Significant variability detected between F2 and F3 progenies for soaked bean weight (SBWT), soaked bean water content (SBWC), and clumps (CLMP) was due to inbreeding effects. General combining ability (GCA) components were highly significant and overshadowed specific combining ability (SCA) components in the F2 and F3 for SBWT, SBWC, split beans (SPLT), and the washed-drained weight coefficient (WDWTR), indicating that additive variance predominated. Ratios of GCA: SCA components were equal to or less than unity for CLMP, washed-drained weight (WDWT), and texture (TEXT), indicating that both additive and nonadditive effects contributed to trait expression. Significant SCA effect variances were noted for `Sanilac', `San Fernando', `Nep-2', and `A-30' for WDWT and TEXT, implying that progeny from crosses of these parents had higher or lower mean values for the traits titan the average expected on the basis of GCA. Graphs of the regression of Vr on Wr showed that genes controlling WDWT and TEXT were completely dominant in most cases. Recurrent selection, which seeks to concentrate favorable alleles with additive effects in populations, may he an effective breeding procedure to improve the culinary quality of dry beans. It is not feasible to breed for TEXT and WDWT simultaneously because of a negative correlation between the traits.
Abstract
A protocol for in vitro propagation was developed with two dry bean (Phaseolus vulgaris L.) cultivars. Shoot cultures were initiated by placing seedling shoot tips (1.0 to 1.5 cm) on Murashige and Skoog (MS) medium in which the effects of kinetin and BA alone or in combination with IAA or NAA were examined with regard to shoot multiplication and root or basal callus formation. The combination of BA (3.0 mg liter–1) and NAA (0.1 mg·liter–1) was most effective in shoot multiplication. At high concentrations of BA or kinetin (>10 mg·liter–1), shoot production and internode elongation decreased markedly and rosette-like cultures with multiple buds developed. Shoots were rooted on basal MS medium. Ramets grew to maturity in the greenhouse or field and produced fertile flowers, pods, and seeds. Chemical names used: N-(2-furanylmethyl)-1H-purin-6-amine (kinetin); N-(phenylmethyl)-1H-purin-6-amine (BA); 1H-indole-3-acetic acid (IAA); 1-naphthaleneacetic acid (NAA).
Abstract
A procedure is outlined for the analysis of major water soluble sugars present in roots of carrot (Daucus carota L.). Fresh root tissue homogenized in methanol-chloroform-water (13:4:3, v/v/v) permitted differential extraction of sugars and carotenoid pigments based on their solubilities in the solvents eliminating the need to decolorize extracts. Moreover, determination of all sugars could be made from the same root extract. The relative concentrations of reducing sugars and total sugars were determined by a method using dinitrosalicylic acid and the enzyme, invertase. Glucose was determined by the glucose oxidase method. Sucrose and fructose were determined colorimetrically using standard anthrone procedures. Recovery of sugars added to extracts and assay solutions agreed with values from control samples in which no sugar was added. This indicated that interfering substances were absent from the samples. The procedure's utility was demonstrated on roots of 4 open pollinated cultivars. Sucrose, glucose, and fructose comprised more than 97% of the total water-soluble sugars in each cultivar. This procedure, because of its precision, economy, and practicality can be applied to genetic research and plant breeding aimed at improving carrot eating quality.
Abstract
A study was conducted to investigate the extent of genetic variations and the interrelationships of several quality traits of cultivars of navy and pinto bean (Phaseolus vulgaris L.) grown at 3 locations in Michigan. The measured traits were seed weight, initial weight of solids, surface color of dry and processed beans (L, aL, bL), weight of soaked beans, hydration ratio, clumps, splits, texture, washed and drained weight, and processed bean moisture. Significant cultivar differences were observed for most of the traits in both classes of beans. Location effects were highly significant for all traits. Certain traits showed significant cultivar × location interactions. Phenotypic correlation coefficients among pairs of characters indicated that, with few exceptions, there were low assocations among quality characters. Principal component analysis confirmed the independence of traits. A selection strategy based on a tandem selection procedure followed by construction of selection indices was suggested.
Two recombinant inbred populations of kidney beans were developed and evaluated for canning quality. One population, composed of 75 recombinant inbred lines (RILs), was from a Montcalm/California Dark Red Kidney 82 cross. The second population, with 73 RILs, was from a Montcalm/California Early Light Red Kidney cross. RILs from both populations were planted in North Dakota in 1996 and Michigan in 1996 and 1997. Beans of each RIL were thermally processed using established procedures. Appearance and degree of splitting of each sample and the check varieties were scored subjectively on a 1-7 scale to represent the minimum and maximum acceptability levels of the traits, respectively. Genotypes and genotype × environment interactions were highly significant based on analyses of variance. In the 75 RIL population, seven lines, based on appearance, consistently appeared in the top 25% in all environments (mean = 4.5; range = 4.0-6.1), and four had consistently high acceptability scores (mean = 4.6; range = 4.0-6.3) for the degree of splitting trait. In the population with 73 RILs, nine lines consistently appeared in the top 25% in all environments based on appearance (mean = 4.6; range = 4.1-5.3). For degree of splitting, nine lines had consistently high acceptability scores (mean = 4.2; range = 3.7-5.1). Appearance and splitting of cooked dry bean are quantitatively inherited traits. The field experiments were useful to obtain RILs for screening to identify molecular markers associated with QTLs. Three primers—OQ11, ON186, and OF5—reported to be useful RAPD markers for processing quality in navy beans are of special interest in the current study.