A new gene for flower color pattern, designated white banner (WB), appeared in material derived from the cross `Harvester' snap bean (Phaseolus vulgaris L.) × Plant Introduction (PI) accession 273666 of scarlet runner bean (P. coccineus L.). The WB character has a white banner petal and pale violet wings (veronica-violet 639/2). The inheritance of the mutant was studied in crosses involving dry bean breeding line 5-593, which has bishops-violet (wild-type) flowers, and genetic stocks v BC2 5-593 (white flowers) and blu BC2 5-593 (blue flowers). Segregation in F2 and F3 progenies from the cross v BC2 5-593 × WB supported the hypothesis that WB is controlled by a single recessive gene that is nonallelic with the V locus. An allelism test with blu BC2 5-593 gave evidence that WB is not allelic with the blu locus. The gene symbol wb is proposed for the gene producing WB.
A. M. Ibrahim and D. P. Coyne
Phaseolus coccineus was found to be cross-pollinated because of extrorse stigmas, hairs around the stigmas, and dehiscence of self-pollen on stylar hairs below the stigmas. Phaseolus coccineus was found to be self-fertile when self pollen was pushed through the stigmatic hairs onto the stigmatic surface. Application of White's nutrient solution to P. coccineus stigma surfaces prior to pollination with P. vulgaris pollen resulted in pollen germination and fertilization. Mature seed with viable hybrid embryos developed in pods with partially broken pedicels and in those removed from the plant and cultured in sealed ‘Ziploc’ bags. Use of these techniques open up new possibilities in bean breeding. Pollen viability was high in the F1 P. coccineus × P. vulgaris, but low in the reciprocal F1. Stigma shape of P. coccineus was dominant in the former F1 but not dominant in the reciprocal. Stigma shape, hairiness of stigma, and cotyledon position were inherited quantitatively in the cross P. vulgaris × P. coccineus, while discrete segregation for cotyledon position was observed in the reciprocal cross. Cotyledon position, stigma shape, hairiness and flower color were controlled by cytoplasmic as well as genic factors.
Kenneth R. Tourjee, James Harding, and Thomas G. Byrne
The frequency distribution of gerbera flower hue in the Davis population of gerbera appears continuous and bimodal. This suggests that a gene of large effect may be segregating in a background of polygenic variation. CSA is a statistical technique developed in genetic epidemiology for investigating such complex traits without the need of inbred lines. The REGC program of SAGE (Elston, LSU Medical Center, New Orleans) uses the regressive models of G. Bonney (1984) through pedigree analysis to provide estimates of major gene parameters and residual correlations among relatives. Pedigrees obtained from generations 14, 15, and 16 indicate that a major dominant gene for hue is segregating and accounting for -0.66 of the total variation. The genotypic means are 32 degrees and 71 degrees for the aa and bb genotypes, respectively. The a allele is dominant to the b allele and has a frequency of 0.55. The residual parent-offspring correlation estimate is 0.2 and measures the genetic contribution to the remainder of the variance.
Kenneth R. Tourjee, James Harding, and Thomas G. Byrne
The frequency distribution of gerbera flower hue in the Davis Population of Gerbera appears continuous and bimodal. This suggests that a gene of large effect may be segregating in a background of polygenic variation. CSA is a statistical technique developed in genetic epidemiology for investigating such complex traits, without the need of inbred lines. The REGC program of SAGE (Elston, LSU Med. Center, New Orleans) utilizes the regressive models of G. Bonney (1984) through pedigree analysis to provide estimates of major gene parameters and residual correlations among relatives. Pedigrees obtained from generations 14, 15, and 16 indicate that a major dominant gene for hue is segregating and accounting for ∼ 0.66 of the total variation. The genotypic means are 32 degrees and 71 degrees for the aa and bb genotypes, respectively. The `a' allele is dominant to the `b' allele and has a frequency of 0.55. The residual parent-offspring correlation estimate is 0.2, and measures the genetic contribution to the remainder of the variance.
New four traits not yet reported were founded. One mutant plant was from a population of 81-1251-D-20M treated with EMS (ethylmethane sulfonate), which had tubular petals. This tubular petal plant had normal pollens in anthers, but could almost not produce its seeds without artificial pollination. It was controlled by one single recessive gene. One new spontaneous dwarf mutant line, R3-10, which bore seedcoatless-like seeds with short pappus, was crossed with normal breeding lines GL5 and 87-25M-2M. From F2 and F3 results, it was found that the two traits (seedcoatless-like and short pappus) were governed by each one single recessive gene. A stem lettuce type cultivar, `Baimach', seemed to be almost green, but was really tinged red, which was extremely suppressed in red color expression. Its tinged red color could not be seen, except on only very limited base parts of the stem and dorsal petal. In two F2 population experiments of the crosses of `Baimach' with `Oakleaf' and 98-43-3, it was found that the suppression of red color expression in `Baimach' was caused by a single recessive gene. It looked different from that of gene “v” (vanishing) by Lindqvist, because the red color of plants with “v” gene of Lindqvist were typically tinged and could be identified easily at a young plant stage, but not that of `Baimach'. I designated these new four genes as Tu-tu (Tu = normal, tu = tubular petal), Pp-pp (Pp = normal, pp = short pappus), Scl-scl (Scl = normal, scl = seedcoatless-like), and In-in (In = normal, in = inhibiting red color expression extremely).
Richard M. Klein
In order to determine whether the concentration of floral petal anthocyanin pigments could be increased, ultraviolet radiations in the UV-A and UV-B wavelength bands were presented to a variety of flowering plants to partly restore those wavelengths filtered out by greenhouse glass. In no tested plant did the supplementary ultraviolet radiation enhance floral anthocyanin content. Supplementary UV radiation has no economic value in greenhouse production of flowering plants.
David G. Adams and Wesley A. Urdahl
Breakage in the floret area of the stem which occurs during harvesting or post-harvest handling in commercially mature snapdragons was investigated. The point of breakage was not influenced by the number of open florets on the stem, provided many unopened buds remain at the apex. Breaking occurred lower on the stem in crops harvested during fall as opposed to summer months. The break point appears to be related to the end of the concentric column of safranin stainable, lignified xylem. Although not without exception, breakage also appears related to flower pigmentation in that anthocyanin (red) containing cultivars tend to break high whereas aurone (yellow) containing cultivars break low in the floret area. These factors suggest a competition for phenyl propanoid precursors which are consumed in both lignification and pigmentation.
S. Asen, K. H. Norris, R. N. Stewart, and P. Semeniuk
The anthocyanin isolated from flowers of Limonium cvs. Twilight Lavender and Midnight Blue was delphinidin 3,5-diglucoside, and that from ‘Blue Bonneť and ‘American Beauty’ was delphinidin 3-glucoside. The major flavonoid co-pigments in all 4 cvs. were luteolin and its 6-C-glucoside (iso-orientin). These co-pigments were also present in white ‘Iceberg’ and yellow ‘Gold Coast’. The range of colors from reddish-purple to blue for the various cvs. was directly related to the pH of the tissue.