Petroleum Ether Separation and Seedcoat Removal Enhance Seed Germination of a Casuarina equisetifolia L. × C. glauca Sieb. ex Spreng Hybrid

Casuarina cunninghamiana Miq. is an introduced species to Florida that has potential as a windbreak plant to help manage canker in citrus groves; however, only Florida sources can be used for that purpose. Local sources of Casuarina are generally adequate seed producers, but germination percentages are frequently poor. Thus, the causes of low seed germination and methods to improve germination were investigated using C. cunninghamiana and a local hybrid (C. equisetifolia L. × C. glauca Sieb. ex Spreng.). Seeds of the hybrid were larger and heavier (88 mg/100 seeds) than those of C. cunninghamiana (mean wt. 67 mg/100 seeds). Shrunken, insect-damaged, and empty seeds, present in all unsorted seed lots, were responsible for poor seed germination of the four seed sources studied. Petroleum ether separation improved germination by dividing seeds into floaters and sinkers. The floater fraction consisted of 47.5% to 93% insect-damaged seeds compared with 9.0% to 43.5% among sinkers. More than 50% of the sinkers were filled seeds and less than 21% in floaters. No empty seeds were sinkers except for one source of C. cunninghamiana. In sorted hybrid seeds, petroleum ether separation eliminated a large proportion of ungerminable seeds (floaters) and seed germination among sinkers was faster with a higher germination percentage than floaters. Cumulative germination of hybrid seeds in a trial involving two temperatures was 23.0% for sunken seeds at 30 °C at the end of 8 weeks compared with 1% of unsorted seeds. Temperature had no significant effect on seed germination. The germination percentage of hybrid seeds with seedcoats removed was 91.0% in the first week of culture compared with only 1.2% in the first week and 12.6% seed germination at the end of 8 weeks' culture of intact seeds.

Download Full-text

Seed Source and Quality Influence Germination in Purple Coneflower [Echinacea purpurea (L.) Moench.]

HortScience ◽

10.21273/hortsci.29.12.1443 ◽

1994 ◽

Vol 29 (12) ◽

pp. 1443-1444 ◽

Cited By ~ 7

Author(s):

N. Wartidiningsih ◽

R.L. Geneve

Keyword(s):

Seed Germination ◽

Dry Weight ◽

Echinacea Purpurea ◽

Germination Percentage ◽

Physiological Maturity ◽

Seed Sources ◽

Purple Coneflower ◽

Temperature Regimes ◽

Two Temperature ◽

Effect Of Light

Six seed lots of purple coneflower were purchased from four commercial seed sources and evaluated for germination in either light or darkness in combination with two temperature regimes (constant 27C vs. alternating 30C for 8 hours and 20C for 16 hours). Seed lot differences accounted for the majority of variation, with two seed lots exhibiting high (81% to 91%) germination and the remaining seed lots having 39% to 66% germination. There was no effect of light on germination, regardless of the seed lot. However, alternating temperatures improved germination in one of the low-germination seed lots. Seed size and inflorescence position did not affect seed germination. Seed harvested at physiological maturity (maximum seed dry weight), but before drying had occurred, had a higher germination percentage than seeds harvested after desiccation, and they maintained a higher germination percentage even after 1 year in storage.

Download Full-text

In Vitro Seed Germination of Kalmia latifolia L. Hybrids: A Means for Improving Germination and Speeding Up Breeding Cycle

HortScience ◽

10.21273/hortsci12829-17 ◽

2018 ◽

Vol 53 (4) ◽

pp. 535-540 ◽

Cited By ~ 1

Author(s):

He Li ◽

Donglin Zhang

Keyword(s):

United States ◽

Seed Germination ◽

Southeastern United States ◽

Germination Percentage ◽

Kalmia Latifolia ◽

Germination Time ◽

Hybrid Seeds ◽

Mature Seeds ◽

Mountain Laurel

Kalmia latifolia L. (mountain laurel), a member of Ericaceae, is a beautiful ornamental shrub native to the eastern United States. The plant is not common in the southeastern United States landscapes because of the limited heat tolerance of most commercial cultivars. Breeding of heat-tolerant cultivars can be achieved by cross hybridization, but is often challenged by low germination percentage, long germination time, and potential abortion of cross-hybridized seeds. We used in vitro seed germination to enhance germination and shorten germination time and investigated the appropriate collecting time, optimal basal medium, and pH for this approach. Collecting time affected in vitro seed germination, with more mature hybrid seeds [collected 4–5 months after pollination (MAP)] having higher germination rate (90% in 4 weeks) than the less mature seeds collected in 2 MAP (20% in 7 weeks). Seedlings from the mature seeds also produced two true leaves on average after 8 weeks of culture, whereas seedlings from the less mature seeds had no true leaves. Woody Plant Medium (WPM) better enhanced in vitro seed germination compared with Murashige and Skoog (MS) or Gamborg’s B5 (B5) medium. WPM yielded higher germination (98%) than MS (90%) and significantly greater total leaf area per seedling (67 mm3) than MS (50 mm3) and B5 (52 mm3) for seeds of ‘Firecracker’ × ‘Snowdrift’. Similar effects had been observed on seeds from ‘Little Linda’ × ‘Starburst’ and ‘Pristine’ × ‘Peppermint’. The pH ranging from 4.2 to 5.4 did not affect seed germination and seedling development of mountain laurel hybrids. Our protocol enabled early collection of mountain laurel hybrid seeds 1 month before their full maturation and permitted seeds to germinate in 4 weeks on WPM, which shortened the period from crossing to the seedling stage from up to 15 to 6 months and enhanced germination percentage from 30% to more than 90% compared with traditional seed germination. This protocol should be applied to promote the breeding and selection of new mountain laurel cultivars for the southeastern United States landscapes.

Download Full-text

The Effects of Pre-germination Treatments on Seed Germination and Growth of Wild Guavas in the Kingdom of Eswatini, Southern Africa

Asian Journal of Agricultural and Horticultural Research ◽

10.9734/ajahr/2020/v5i130041 ◽

2020 ◽

pp. 28-36

Author(s):

Thulani Sikhondze ◽

Kwanele A. Nxumalo ◽

Michael T. Masarirambi ◽

Paul K. Wahome ◽

Mathole G. Zwane

Keyword(s):

Seed Germination ◽

Sulphuric Acid ◽

Growth And Development ◽

Seed Priming ◽

Psidium Guajava ◽

Germination Percentage ◽

Hot Water ◽

Distilled Water ◽

Ecological Zones ◽

Poor Seed

Dormancy is a condition where seeds will not germinate even when the environmental conditions (water, temperature and aeration) are permissive for germination. Wild guavas (Psidium guajava L.) are very popular in all agro-ecological zones of Eswatini. Farmers have shown an interest towards guava cultivation but have to cope with the shortage of quality propagation material. The demand is not fulfilled because of unavailability of superior seedling rootstocks, which might be due to poor seed germination and seedling growth. Nevertheless, it has been reported that guava seeds exhibited seed dormancy, which affects their growth and development. The experiment was carried out to study effects of different pre-germination methods on seed germination of guava. The study was conducted at the University of Eswatini, Luyengo Campus. The objective of the study was to get maximum germination of guava seeds in as short a time as possible. Four methods were used i.e., soaking in distilled water for five days at room temperature, soaking in hot water at 80ºC for three minutes, subjecting seeds to heat at 80ºC in oven for six minutes and soaking in 20% dilute sulphuric acid for three minutes. All these treatments significantly decreased days to germination of seeds compared with the control. Among the methods, treatment of guava seeds with 20% dilute sulphuric acid for three minutes was judged best with maximum germination percentage (93.3%); lowest germination mean time was observed in seeds soaked in distilled water (31 days). Highest plant height (44 mm) and highest stem girth of (3.37 mm) were recorded from seeds soaked in sulphuric acid after 150 days of sowing. Seeds without any pre-germination treatment showed poor germination (26.7%). On the basis of the findings, it can be recommended that propagators use sulphuric acid in seed priming for higher germination, growth and development.

Download Full-text

Germination of Fully Developed Corylopsis Seeds Influenced by Harvest Date and Cold Stratification

HortScience ◽

10.21273/hortsci13032-18 ◽

2018 ◽

Vol 53 (9) ◽

pp. 1360-1363 ◽

Cited By ~ 1

Author(s):

Ji Hee Kim ◽

Jeung Keun Suh ◽

Seong-Tak Yoon ◽

Pablo Jourdan ◽

Mark S. Roh

Keyword(s):

Seed Germination ◽

Germination Percentage ◽

Harvest Date ◽

Cold Stratification ◽

X Ray ◽

Date Seed ◽

Seed Maturity ◽

Internal Structures ◽

Empty Seeds

Corylopsis seed germination tests were conducted to assess the influence of harvest date (seed maturity) and cold stratification (CS) at 5 °C. Corylopsis gotoana seeds harvested on 12 July, 2 and 22 Aug., 6 and 20 Sept., and 1 and 10 Oct. 2011 were immersed in water for 20 min to separate fully developed seeds (full seeds) from empty seeds by floatation, and by X-ray scanning to identify full from empty seeds (Expt. 1). Immersing seeds in water did not effectively separate full seeds from empty seeds as evaluated by seed germination tests. Seeds harvested on or around 6 Sept. that sank showed translucent X-ray images with fully developed internal structures composed of embryo, cotyledons, and endosperm, and were considered mature. Without CS, >12% seeds harvested on 20 Sept. germinated, regardless of whether seeds were full or empty. Seeds of C. coreana harvested on 5 and 15 Sept., and 5 and 18 Oct. were stored dry at 20 °C until 27 Dec. and germinated after 0, 3, 6, 9, and 12 weeks of CS (Expt. 2). Longer than 6 weeks of CS was required to accelerate and increase the germination of seeds harvested on or after 5 Sept. Germination percentage of full seeds harvested on Oct. 18 was increased to >72% as the duration of CS treatment increased to 12 weeks. In conclusion, fully developed seeds harvested on or after 6 Sept. were considered mature and 6 weeks of CS accelerated germination and increased the germination percentage. Further, dormancy of Corylopsis seeds appears to be shallow since germination occurred without any CS.

Download Full-text

Assessing tree germination resilience to global warming: a manipulative experiment using sugar maple (Acer saccharum)

Seed Science Research ◽

10.1017/s0960258516000040 ◽

2016 ◽

Vol 26 (2) ◽

pp. 153-164 ◽

Cited By ~ 13

Author(s):

Kevin A. Solarik ◽

Dominique Gravel ◽

Aitor Ameztegui ◽

Yves Bergeron ◽

Christian Messier

Keyword(s):

Seed Germination ◽

Constant Temperature ◽

Climate Warming ◽

Acer Saccharum ◽

Sugar Maple ◽

Incubation Temperature ◽

Germination Percentage ◽

Seed Sources ◽

Seed Origin ◽

Maple Seed

AbstractA climate warming of 2–5°C by the end of the century will impact the likelihood of seed germination of sugar maple (Acer saccharum), a dominant tree species which possesses a restricted temperature range to ensure successful reproduction. We hypothesize that seed origin affects germination due to the species' local adaptation to temperature. We tested this by experimentally investigating the effect of incubation temperature and temperature shifting on sugar maple seed germination from seven different seed sources representing the current species range. Survival analysis showed that seeds from the northern range had the highest germination percentage, while the southern range had the lowest. The mean germination percentage under constant temperatures was best when temperatures were ≤5°C, whereas germination percentages plummeted at temperatures ≥11°C (5.8%). Cool shifting increased germination by 19.1% over constant temperature treatments and by 29.3% over warm shifting treatments. Both shifting treatments caused earlier germination relative to the constant temperature treatments. A climate warming of up to +5°C is shown to severely reduce germination of seeds from the southern range. However, under a more pronounced warming of 7°C, seed germination at the northern range become more affected and now comparable to those found from the southern range. This study states that the high seed germination percentage found in sugar maple at the northern range makes it fairly resilient to the warmest projected temperature increase for the next century. These findings provide forest managers with the necessary information to make accurate projections when considering strategies for future regeneration while also considering climate warming.

Download Full-text

Maternal source affects seed germination of a rare Arabian desert species (Astragalus sieberi)

Botany ◽

10.1139/cjb-2020-0144 ◽

2021 ◽

Author(s):

Arvind Bhatt ◽

María Mercedes Carón ◽

Paulo Roberto de Moura Souza-Filho ◽

David Gallacher

Keyword(s):

Seed Germination ◽

Seedling Emergence ◽

Germination Percentage ◽

Population Variation ◽

Source Selection ◽

Seed Sources ◽

Native Seed ◽

Germination Characteristics ◽

Desert Areas

Understanding variation of seed germination in wild populations can assist restoration projects through improved seed source selection. Recruitment of artificially distributed seed can be improved by selecting for suitable dormancy and germination characteristics. We investigated seed germination and emergence responses of three Astragalus sieberi populations (Abdali, Liya and Salmi) to in situ storage for 5 months at depths of 0 and 5 cm, pre-sowing hydration for 12 and 24 hours, and chemical scarification with concentrated sulfuric acid for 5, 10 and 15 minutes. Germination percentage was low for freshly collected seeds (< 3%) from Abdali and Salmi. In situ storage partially enhanced germination. Pre-sowing hydration did not affect seedling emergence, but acid scarification effectively broke seed dormancy. The longest scarification treatment of 15 min produced the greatest seedling emergence, though populations responded differently. Results indicate that selection of maternal seed sources can improve revegetation projects of desert areas with native seed sources. Knowledge of inter-population variation can improve the understanding of the mechanisms regulating seed germination, thus optimizing restoration projects by selecting optimal seed sources.

Download Full-text

Effect of H2O-Based Low-Pressure Plasma (LPP) Treatment on the Germination of Bambara Groundnut Seeds

Agronomy ◽

10.3390/agronomy11020338 ◽

2021 ◽

Vol 11 (2) ◽

pp. 338

Author(s):

Naeem Ahmed ◽

Asad Masood ◽

Kim S. Siow ◽

M. F. Mohd Razip Wee ◽

Rahmat Zaki Auliya ◽

...

Keyword(s):

Food Security ◽

Seed Germination ◽

Chemical Modification ◽

Low Pressure ◽

Germination Percentage ◽

Bambara Groundnut ◽

Pressure Plasma ◽

Low Pressure Plasma ◽

Amine Groups

In general, seed germination is improved by low-pressure plasma (LPP) treatment using precursors such as air, nitrogen, argon, or water (H2O). Here, H2O-based LPP treatment using the optimized parameters of 10 W and 10 s improves the germination of Bambara groundnut seeds by 22%. LPP increases the wettability and roughness of the seed hilum while oxidizing the surface with carboxyl and amine groups. In this H2O-based treatment of Bambara groundnut seeds, combinatory etching and chemical modification facilitated the imbibition process and increased the germination percentage. The success of this method has the potential to be scaled up to solve food security with seeds otherwise facing germination-related issues.

Download Full-text

Asymbiotic germination of Vanilla planifolia in relation to the timing of seed collection and seed pretreatments

Botanical Studies ◽

10.1186/s40529-021-00311-y ◽

2021 ◽

Vol 62 (1) ◽

Author(s):

Chih-Hsin Yeh ◽

Kai-Yi Chen ◽

Yung-I. Lee

Keyword(s):

Seed Germination ◽

Seed Development ◽

Seed Coat ◽

Germination Percentage ◽

Vanilla Planifolia ◽

Outermost Layer ◽

Seed Collection ◽

Seed Pretreatment ◽

Immature Seeds ◽

Mature Seeds

Abstract Background Vanilla planifolia is an important tropical orchid for production of natural vanilla flavor. Traditionally, V. planifolia is propagated by stem cuttings, which produces identical genotype that are sensitive to virulent pathogens. However, propagation with seed germination of V. planifolia is intricate and unstable because the seed coat is extremely hard with strong hydrophobic nature. A better understanding of seed development, especially the formation of impermeable seed coat would provide insights into seed propagation and conservation of genetic resources of Vanilla. Results We found that soaking mature seeds in 4% sodium hypochlorite solution from 75 to 90 min significantly increased germination. For the culture of immature seeds, the seed collection at 45 days after pollination (DAP) had the highest germination percentage. We then investigated the anatomical features during seed development that associated with the effect of seed pretreatment on raising seed germination percentage. The 45-DAP immature seeds have developed globular embryos and the thickened non-lignified cell wall at the outermost layer of the outer seed coat. Seeds at 60 DAP and subsequent stages germinated poorly. As the seed approached maturity, the cell wall of the outermost layer of the outer seed coat became lignified and finally compressed into a thick envelope at maturity. On toluidine blue O staining, the wall of outer seed coat stained greenish blue, indicating the presence of phenolic compounds. As well, on Nile red staining, a cuticular substance was detected in the surface wall of the embryo proper and the innermost wall of the inner seed coat. Conclusion We report a reliable protocol for seed pretreatment of mature seeds and for immature seeds culture based on a defined time schedule of V. plantifolia seed development. The window for successful germination of culturing immature seed was short. The quick accumulation of lignin, phenolics and/or phytomelanins in the seed coat may seriously inhibit seed germination after 45 DAP. As seeds matured, the thickened and lignified seed coat formed an impermeable envelope surrounding the embryo, which may play an important role in inducing dormancy. Further studies covering different maturity of green capsules are required to understand the optimal seed maturity and germination of seeds.

Download Full-text

Effect of Environmental Factors on the Germination and Emergence of Drunken Horse Grass (Achnatherum inebrians)

Weed Science ◽

10.1017/wsc.2020.81 ◽

2020 ◽

pp. 1-29

Author(s):

Yonghuan Yue ◽

Guili Jin ◽

Weihua Lu ◽

Ke Gong ◽

Wanqiang Han ◽

...

Keyword(s):

Seed Germination ◽

Environmental Factors ◽

Abiotic Factors ◽

Seedling Emergence ◽

Management Strategies ◽

Germination Percentage ◽

Western China ◽

Burial Depth ◽

Achnatherum Inebrians ◽

Water Ph

Abstract Drunken horse grass [Achnatherum inebrians (Hance) Keng] is a perennial poisonous weed in western China. A comprehensive understanding of the ecological response of A. inebrians germination to environmental factors would facilitate the formulation of better management strategies for this weed. Experiments were conducted under laboratory conditions to assess the effects of various abiotic factors, including temperature, light, water, pH and burial depth, on the seed germination and seedling emergence of A. inebrians. The seeds germinated at constant temperatures of 15, 20, 25, 30, 35°C and in alternating-temperature regimes of 15/5, 20/10, 25/15, 30/20, 35/25, 40/30°C, and the seed germination percentages under constant and alternating temperatures ranged from 51% to 94% and 15% to 93%, respectively. Maximum germination occurred at a constant temperature of 25°C, and germination was prevented at 45/35°C. Light did not appear to affect seed germination. The germination percentage of seeds was more than 75% in the pH range of 5 to 10, with the highest germination percentage at pH 6. The seeds germinated at osmotic potentials of 0 MPa to -1.0 MPa, but decreasing osmotic potential inhibited germination, with no germination at -1.2MPa. After 21 d of low osmotic stress, the seeds that did not germinate after rehydration had not lost their vitality. The seedling emergence percentage was highest (90%) when seeds were buried at 1 cm but declined with increasing burial depth and no emergence at 9 cm. Deep tillage may be effective in limiting the seed germination and emergence of this species. The results of this study provide useful information on the conditions necessary for A. inebrians germination and provide a theoretical basis for science-based prediction, prevention and control of this species.

Download Full-text

The Effect of High Concentrations of Ethylene on Seed Germination of Douglas Fir (Pseudotsugamenziesii (Mirb.) Franco)

Canadian Journal of Forest Research ◽

10.1139/x75-058 ◽

1975 ◽

Vol 5 (3) ◽

pp. 419-423 ◽

Cited By ~ 4

Author(s):

Carey Borno ◽

Iain E. P. Taylor

Keyword(s):

Seed Germination ◽

Germination Rate ◽

Inhibitory Effect ◽

Germination Percentage ◽

Douglas Fir ◽

Control Treatment ◽

Continuous Exposure ◽

Short Term ◽

Short Term Exposure ◽

High Concentrations

Stratified, imbibed Douglas fir (Pseudotsugamenziesii (Mirb.) Franco) seeds were exposed to 100% ethylene for times between 0 and 366 h. Germination rate and germination percentage were increased by treatments up to 48 h. The 12-h treatment gave largest stimulation; 30% enhancement of final germination percentage over control. Treatment for 96 h caused increased germination rate for the first 5 days but reduced the germination percentage. Germinants were subject to continuous exposure to atmospheres containing 0.1 – 200 000 ppm ethylene in air, but it did not stimulate growth, and the gas was inhibitory above 100 ppm. Although some effects of high concentrations of ethylene may have been due to the lowering of oxygen supplies, this alone was insufficient to account for the full inhibitory effect. The mechanism of stimulation by short-term exposure to ethylene is discussed.

Download Full-text