Abstract
An inhibitor was present in both seed coat and embryo of a high and a low chilling cv. of unstratified peach seeds and its concn decreased as stratification proceeded, Embryonic tissue retained more of the inhibitor than the seed coat. As the concn of inhibitor decreased, seed germination increased. The inhibitor was tentatively identified as abscisic acid (ABA) by chromatography. A bound inhibitor was also present in the seed parts of both cvs., and its concn increased in the embryo as stratification proceeded. More ABA and bound inhibitor were present in the high-chilling cv. than in the low-chilling counterpart, indicating that they may be related as factors which cause a cv. to require long periods of chilling. Application of ABA reduced germination percentage on stratified seeds without seed coats. Application of gibberellic acid (GA) and N-benzyladenine (BA) combined had a synergistic effect in promoting germination of dormant seeds.
Abstract
No differences were observed in water uptake, respiration rate and seed coat morphology of ‘New Era Bright Red’ and ‘New Era Dark Red’ geranium. Water uptake in some seeds was rapid in the first 12 hours following initiation of imbibition. Radicle emergence and germination occurred 3 days after swelling and respiratory activity began as soon as seeds imbibed water. Nonswollen seeds did not germinate. Seed coat surfaces appeared wax-like in both cultivars and no relationship between occlusion of the hilum fissure and germination was observed. Dipping seed in concentrated H2SO4 or hot water, or removing a portion of the seed, increased germination rate and germination to nearly 100%. Results suggest the seed coat in geraniums can be impervious to water uptake.
Abstract
For prompt germination the seed of Russian olive (Elaeagnus angustifolia L.) required 9 to 12 weeks of after-ripening at a temperature of 5° C. When fruit and endocarp were removed, 50–60% of the non-after-ripened seed germinated. Complete germination was obtained by removing the endocarp and the seed coats. The germination inhibition appeared to be related to non-leachable inhibitors in both of these structures, and their influence was almost entirely restricted to the radicle end of the embryo. Kinetin was very effective in breaking the dormancy linked to the seed coats but did not influence dormancy when the endocarp was present.
Abstract
Red stem, found in PI 157083, is controlled by a single recessive gene, r. Red pigment appeared in vascular traces of hypocotyls about 2 weeks after planting. Seed coat color of red-stemmed plants was reddish or tan, in contrast to white or yellow seed coats of green-stemmed plants. Pale, a spontaneous mutant in a second backcross hybrid from ‘Campo’ × PI 180280, is controlled by a single partially dominant gene, Pa, which acts as a recessive lethal: Pa/Pa plants die; Pa/+ are pale; and +/+ are normal. Pale did not affect expression of red stem. Testcross segregations fit the expected ratio for independent assortment of the 2 loci.
Abstract
Effects of growth regulators on parthenocarpic fruit development in muskmelon (Cucumis melo L.) were tested under field conditions. Parachlorophenoxyacetic acid (4-CPA) β-naphtoxyacetic acid (β-NOA), gibberellin (GA4+7), and 2-chloro-9-hydroxyfluorene-9-carboxylic acid (chlorflurenol) caused parthenocarpy, when applied directly to flowers at anthesis. Seed coat developed in all parthenocarpic fruits. A positive correlation (r = 0.80) was found between number of seeds, seed coats, and fruit weight. Fruit set was induced under field conditions without bees, by a single spray of 4-CPA or β-NOA or chlorflurenol applied to the entire plant.
Abstract
Seed germination rate and percentage of maile (Alyxia olivaeformis Gaud.) were improved by removal of the fleshy seed coat and preconditioning with growth regulators. Preplant soaking for 48 or 72 hours with 100 ppm kinetin, 2000 ppm potassium nitrate (KNO3), 500 ppm or 1000 ppm gibberellic acid (GA) were the most effective treatments.
Abstract
Seed germination of ‘Royal Mix’ freesia was most rapid and uniform at 15.5° or 18.5°C under clear polyethylene or at 13° or 21.5°C under black polyethylene. Soaking seeds in running water prior to germination or removal of the seed coat did not improve seed germination
Abstract
‘Royal Blackeye’ southernpea [Vigna unguiculata (L.) Walp.] was released in 1985 by the Louisiana Agricultural Experiment Station. This southernpea was developed primarily for local fresh market use. The purple hulls and blackeye seed coat pattern combination is unique among released cultivars.
Abstract
Lima beans (Phaseolus lunatus L.) were selected for ability to germinate and grow vigorously under 12°C (12 hours)/10° (12 hours) temperatures; 15° is required for good germination of current cultivars. Seed coat color was not associated with cold germination ability.
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.