Abstract
In the tomato (Lycopersicon esculentum Mill.) the ability of PI 341988 to germinate at 10°C is controlled by a recessive gene, tentatively symbolized Itg.
Abstract
A 24 or 48 hour soak in gibberellins (GA) did not influence the total germination of open-pollinated rabbiteye blueberry seeds (Vaccinium ashei Reade, cv. Tifblue). GA4+7 at 100-500 ppm stimulated early germination of seeds from the 2nd to 4th week after sowing, with the maximum effect occurring after 3 weeks. The 48-hour, GA4+7, 100 ppm treatment stimulated germination from the 2nd to 5th week after sowing. Stimulation of earlier germination by GA4+7 hastened seedling transplanting by 2 to 4 weeks. Germination of mature seeds (large, filled) was significantly higher than immature (medium-size, filled) or imperfectly (partially-filled) developed seeds. GA4+7 did not increase germination of immature or imperfectly developed seeds.
Abstract
Embryo growth of the pecan (Carya illinoensis (Wang.) K. Koch) is mechanically restricted by the shell. This effect can rapidly be overcome by germinating the seeds between 30 and 35°C.
Abstract
Seed of pepper (Capsicum annuum L. cv. Early Calwonder) receiving a sodium hypochlorite treatment germinated faster and showed more rapid early growth than seed treated with water alone or with sodium hypochlorite followed by an acid rinse.
Abstract
Seeds of tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.) were either germinated before planting, primed (immersed in an aerated solution of potassium phosphate and ammonium phosphate for 72 hours (tomato) or 120 hours (pepper) and dried), or left untreated (raw) and then planted with gel in loamy sand and sandy soils. There was little difference in response from the tomato seed treatments. In pepper, germinated seeds emerged much earlier and established heavier plants. Differences in emergence due to seed treatments generally were greater in loamy sand than in sandy soil.
Abstract
The endocarp of ‘Manzanillo’ olive (Olea europaea L.) seeds was subjected to several treatments in order to determine its effect on germination of the olive seed. The endocarp inhibited germination in stratified as well as unstratified olive seeds. Removing the endocarp resulted in high percentages of germination, but only when it was completely removed or when the radicle end was removed. The endocarp did not inhibit germination by preventing imbibition, since water uptake occurred in the seed through the untreated endocarp and through the clipped cotyledon end. The endocarp also did not contain water soluble inhibitors that prevent germination. Rather, the endocarp seemed to inhibit germination through mechanical resistance. High percentages of germination can occur only when the structure of the endocarp is altered, reducing its resistance to embryo expansion.
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.
Pollen viability, in-vivo pollen tube growth, fruit ripening, seed germination, seed weight, whole plant vigor, and natural flower senescence were investigated in homozygous and heterozygous transgenic ethylene-insensitive CaMV35S::etr1-1 petunias (Petunia ×hybrida `Mitchell Diploid'). Homozygous or heterozygous plants were used to determine any maternal and/or paternal effects of the CaMV35S::etr1-1 transgene. All experiments except for those used to determine natural flower senescence characteristics were conducted in both high and low temperature greenhouses to determine the effect of temperature stress on transgenic plants when compared to wild-type. Results indicated that ethylene-insensitive plants had a decrease in pollen viability, root dry mass, seed weight, and seed germination. Fruit ripening, seed germination, and seed weight were maternally regulated. In contrast, the CaMV35S::etr1-1 transgene is completely dominant in its effect on natural flower senescence.
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.
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.