Abstract
Seeds of 2 cultivars of sweet pepper (Capsicum annuum L.) were invigorated by presoaking in a −8 bar solution of polyethylene glycol-6000 (240 g/liter H2O) at 15°C for 5 days. Invigorated seed germinated and emerged faster than noninvigorated in the greenhouse and laboratory, but not in the field. In the last field planting, yield from invigorated ‘Yolo Wonder L.’ was significantly greater than the control seed. Various seed treatments (KC1, KNO3, indoleacetic acid and gibberellic acid) in combination with the osmoticum did not affect invigoration.
Abstract
Trees and fruit of 6 early ripening cultivars of peach and nectarine [Prunus persica (L.) Batsch] were sprayed about 4 weeks prior to commercial harvest with either butanedioic acid mono-(2,2-dimethylhydrazide) (daminozide), maleic hydrazide, or thiourea. The date of 50% drop of overripe fruit was retarded one to 4 days. Chemical treatments increased germination of in vitro embryo culture of ‘Fla. 3-1’ and ‘Flor-daking’ up to 27-32%. Seed germination from cracked pits of ‘Fla. 7-3N’, ‘Fla. 7-4N’, ‘Earligrande’, and ‘Fla. M6-6N’ generally increased up to 50%. The delayed fruit drop did not appear to account for all of the increase in germination. The results support an enhancement of embryo development in addition to that attributed to delayed fruit maturity.
Abstract
Embryos of American ginseng (Panax quinquifolius L.) seeds stratified 570 days at 0° or 5°C did not increase in size, whereas embryos of seeds stratified 570 days at 20° grew to a length of 2.5 mm. Embryos of seeds stratified at 5° for 120 days, treated with 1000 ppm gibberellic acid (GA), then transferred to 20° grew to the same length as those held at a constant 20°. None of the GA treated seeds germinated. However, seeds stratified outdoors and those provided 5° for 120 days, 20° for 300 days, and then held at 5°C germinated after 540 days. The embryos of these latter treatments had similar growth patterns. Growth of the cotyledons paralleled the growth of the entire embryo. Cool-warm-cool stratification patterns are necessary for efficacious germination of American ginseng seeds.
Seed germination patterns were studied in Echinacea purpurea (L.) Moench grouped by seed source, one group of seven lots from commercially cultivated populations and a second group of nine lots regenerated from ex situ conserved wild populations. Germination tests were conducted in a growth chamber in light (40 μmol·m–2·s–1) or darkness at 25 °C for 20 days after soaking the seeds in water for 10 minutes. Except for two seed lots from wild populations, better germination was observed for commercially cultivated populations in light (90% mean among seed lots, ranging from 82% to 95%) and in darkness (88% mean among seed lots, ranging from 82% to 97%) than for wild populations in light (56% mean among seed lots, ranging from 9% to 92%) or in darkness (37% mean among seed lots, ranging from 4% to 78%). No germination difference was measured between treatments in light and darkness in the commercially cultivated populations, but significant differences were noted for treatments among wild populations. These results suggest that repeated cycles of sowing seeds during cultivation without treatments for dormancy release resulted in reduced seed dormancy in E. purpurea.
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
Seeds of winged bean, accessions TPt-1 and ‘Chimbu’, treated in dilute H2SO4 (8:1 by volume in H2O) for 5 minutes at 62°C followed by a 5 minute rinse under running tap water gave 96-100% germination with no apparent injury to the emerging seedlings.
Abstract
Most progenies from intercrossed or outcrossed inbred selections of strawberry (Fragaria × ananassa Duch.), germinated as well or better than a control outcross between 2 vigorous noninbred clones. Germination of an S3 progeny was lower than the control. In general, inbreeding reduced seedling vigor while intercrossing or outcrossing of inbreds restored vigor. Germination total and rate as expressed by an index were unrelated to subsequent seedling growth.
Abstract
Seeds of Acacia cyanophylla Lindl. were treated by: 1) placing in boiling water and cooling to room temperature; 2) boiling in water for 5 or 10 min and cooling to room temperature; 3) soaking in concentrated H2SO4 at room temperature or at 50°C for 30, 60, 90, and 120 minutes. Seeds from all treatments were germinated at 5, 10, 15, 20, 25, 30, and 35°C in the dark. All pre-sowing treatments increased the germination percentage and rate over controls. Seeds treated with concentrated H2SO4 for 90 minutes and germinated at 15° had 98.5% germination in 6 days.
Abstract
Seed germination of Alexandra palm [Archontophoenix alexandrae (F. J. Muell,) H. Wendl & Drude] was accelerated by presoaking for 24 or 72 hours in water, and further accelerated by a 72 hour treatment with 100 or 1000 ppm, gibberellic acid (GA), but not with benzyladenine (BA) or naphthaleneacetic acid (NAA).
Cones of six provenances (Escambia Co., Ala., Santa Rosa Co., Fla., Wayne Co., N.C., Burlington Co., N.J., New London Co., Conn., and Barnstable Co., Mass.) of Atlantic white cedar [Chamaecyparis thyoides (L.) B. S. P.], were collected Fall 1994 (Alabama, North Carolina, New Jersey, and Connecticut), Winter 1995 (Massachusetts), or Fall 1995 (Florida). Cones were dried for 2 months, followed by seed extraction and storage at 4°C. Seeds were then graded and stratified (moist-prechilled) for 0, 30, 60, or 90 days. Following stratification, seeds were placed at 25°C or an 8/16-hr thermoperiod of 30°/20°C with daily photoperiods of 0, 1, or 24 hr. Germination was recorded every 3 days for 30 days. Temperature, stratification, and light had significant effects on germination. However, responses to these factors varied according to provenance. Averaged over all treatments, the Alabama provenance exhibited the greatest germination (61%), followed by the Florida provenance (45%), with the remaining provenances ranging from 20% to 38%. However, there were specific treatments for each provenance that resulted in germination > 50%. The three southern provenances (Alabama, Florida, and North Carolina) required 30 days of stratification for maximum germination. They did not exhibit an obligate light requirement, but photoperiods ≥ 1 hr increased germination greatly over seeds in darkness. In contrast, the northern provenances (New Jersey, Connecticut, and Massachusetts) had an obligate light requirement. These provenances only required 30 days stratification with continuous light for maximum germination. When subjected to a 1-hr photoperiod, seeds from the northern provenances required longer durations of stratification for maximum germination. Regardless of the length of stratification, the New Jersey provenance required a 24-hr photoperiod to maximize germination. When averaged over all treatments, total germination for each provenance was greater at 30°/20°C than 25°C (43% vs. 31%).