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Open access

H. Nerson, H. S. Paris, Z. Karchi, and M. Sachs

Abstract

Watermelon [Citrullus lanatus (Schrad.) Matsum. & Nakai] seeds of the tetraploid ‘Alena’ and the diploid ‘Sugar Baby’ were subjected to one of several treatments prior to germination at 17°, 21°, and 25°C, including lateral splitting, soaking in H2O (aerated or nonaerated), GA4+7, or benzyladenine (BA) for 24 hr, or in KNO3 for 5 days, followed by drying. These treatments were successful in increasing germination percentage of ‘Alena’ seeds. Soaking treatments increased ‘Alena’ embryo length. ‘Alena’ seeds possessed thicker seed coats, larger seed cavities, and absorbed more water than those of their diploid counterpart, ‘Sugar Baby’.

Open access

Veronica M. Valdes and Kent J. Bradford

Abstract

Lettuce (Lactuca sativa L. ‘Empire’) seeds (achenes) were primed in aerated solutions of polyethylene glycol 8000 (−1.56 MPa) for 24 hr at 18°C and dried to 6% water content. Control (untreated) and primed seeds then were commercially coated in a clay-based material (Royal Sluis Splitkote). Priming prevented the occurrence of thermodormancy in seeds imbibed at temperatures between 32° and 37° and accelerated the rate of germination at all temperatures tested. Coating delayed germination slightly and reduced the maximum germination temperature of control seeds. Primed seeds exhibited thermodormancy when tested immediately after coating, but they soon regained their capacity for high-temperature germination. When tested after 5 months of storage at 5°, primed seeds germinated at temperatures up to 37° regardless of coating. Osmotically primed seeds retained the capacity for germination at high temperature after seed coating and storage, providing an effective means of improving stand establishment of direct-seeded lettuce in hot weather.

Free access

Jocelyn A. Ozga and F.G. Dennis Jr.

Exposure of stratified apple (Malus domestics Borkh. cv. Golden Delicious) seeds to 30C induces secondary dormancy. To determine if an increase in abscisic acid (ABA) content was associated with the loss in germination capacity, stratified seeds (3,- 6, or 9 weeks at 5C) were held at 30C for 0, 3, or 6 days. Stratification at 5C either had no effect or increased ABA content in embryonic axes, cotyledons, and seed coats. Exposure to 30C after stratification either did not affect or decreased ABA content of embryonic axes and seed coats; in contrast, cotyledonary ABA was increased. Seed coats, cotyledons, and embryonic axes stratified for 3, 6, or 9 weeks at 20C contained the same or higher levels of ABA in comparison with nonstratified seeds or seeds stratified at SC. Changes in ABA levels were not consistently correlated with changes in germination capacity during stratification or after exposure to 30C. These data suggest that changes in ABA are not related to changes in dormancy. Chemical names used: abscisic acid (ABA); butylated hydroxy-toluene (BHT); n-(trichloromethyl) thio-4-cyclohexene-1,2-dicarboximide(Captan).

Open access

D. M. Lancaster, A. C. Miller, C. E. Johnson, and W. A. Young

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.

Open access

M. H. Dickson

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.

Open access

M. J. Tanabe

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.

Free access

R. L. Fery, P. D. Dukes, and F. P. Maguire

The Agricultural Research Service of the United States Department of Agriculture announced the release of `Bettergreen' southernpea on 30 April 1991. `Bettergreen' is a cream-type cultivar that is homozygous for a newly discovered gene(s) conditioning a unique green cotyledon trait. `Bettergreen' can be harvested at the near-dry seed stage of maturity without loss of the seed's fresh green color. The color of the peas harvested upon reaching “dry-stage” maturity is light olive, and the color is present in both the seed coat and the cotyledons. The fresh peas are small (22 g per 100 peas), ovate to reniform in shape, and have excellent culinary quality. The dried peas have a smooth seed coat. `Bettergreen' is recommended for use as a home garden and fresh market cultivar for spring, mid-season, and fall plantings throughout the southeastern United States. It is particularly recommended for trial as a commercial processing cultivar for the frozen food industry.

Open access

Steve Lin, Walter E. Splittstoesser, and William L. George

Abstract

Pseudoembryos, produced from endothelial proliferation, were found in parthenocarpic fruits of ‘Severianin’ tomato (Lycopersicon esculentum Mill.)· The pseudoembryos did not increase in size after 12 days after anthesis and no endosperm or embryo occurred. At maturity, pseudoembryos became yellow-white in color and had developed a seed coat and thickened radial walls which appeared like hairs. Parthenocarpic fruits had complete locular development, similar to seeded fruits.

Open access

G Shannon Smith

Abstract

Rate and percent germination of Zamia integrifolia Ait. and Z. furfuracea L.f. can be significantly improved by seed scarification. Reported germination times of up to a year or more can be reduced to 1 to 3 months under greenhouse conditions if the outer fleshy seed coat is removed and the inner stony layer scarified. Rate and percent germination vary with placement of scarification cut and species. Germination of 80 to 100% in 1 week were obtained for Z. integrifolia under laboratory conditions.

Free access

Rodney Jones and Robert Geneve

Redbud (Cercis canadensis) is a small woody ornamental legume that has a hard seed coat, which imposes physical dormancy, typical of many legumes. Redbud also possesses an internal embryo dormancy that must be overcome by stratification. In order to observe the relationship between anatomy and germination, seeds were embedded in JB-4 resin during various developmental and germination stages. The seeds were cut longitudinally with a glass bladed microtome, to observe the radicle, vascular traces and testa. It appears that the vascular traces left from the funiculus serve as a weak point in non-dormant seeds that allows the radicle to rupture the testa during germination.