Interaction of Growth Inhibitor and a Natural Germination Stimulator in the Dormancy of Fraxinus excelsior L.

Villiers, T. A.; Wareing, P. F.

doi:10.1038/185112b0

Cited by 65 publications

(20 citation statements)

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“…Furthermore, woody individuals often installed before abandonment. Although the studied species do not have a long lasting dormant seed bank, the seeds of Fraxinus angustifolia are probably dormant for one year, as observed for F. excelsior L. (Villiers and Wareing 1960). The seeds of Phillyrea angustifolia can also germinate one year after dispersal if they have not encountered previously sufficiently moist conditions in the soil (Lepart pers.…”

Section: Age Structurementioning

confidence: 99%

Establishment of woody plants in Mediterranean old fields: opportunity in space and time

Debussche

Lepart

1992

Landscape Ecol

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The establishment of woody plants following agricultural abandonment in the Mediterranean region is a very widespread process which underlines the extent of the rural exodus. The installation windows in space and time were studied in the French Mediterranean region for two common woody plants, Buxus sempervirens and Fraxinus angustifolia and for a group of common woody fleshy-fruited species. These plants differ in their principal modes of dispersal which are respectively, barochory, anemochory and ornithochory. Their installation was analyzed in relation to the seed shadows, the spatial patterns and the age structures of the seedlings. The majority of the seeds were dispersed over short distances, although some animal vectors may promote a limited amount of long distance dispersal. Hence, whatever the mode of dispersal, a few seeds are often dispersed far from the maternal plant. The combination of several dispersal types in one plant species is a frequently observed feature, one being dominant at a small scale, and related to successional processes, the other being dominant at a larger scale and related to invasive processes. In the old fields the spatial pattern of seedlings closely follow the observed seed shadows. However, competition with the maternal plants may lead to, in some cases, a recruitment deficit close to the seed-bearers. Age structures show that woody plants often install very early after the abandonment of cultivation and that the installation window in time is shortened by the development of a dense herbaceous cover. It is concluded that the installation of woody plants in Mediterranean old fields cannot be reduced to a general rule. The rate and extent of installation depends mainly on the spatial distribution of the seed-bearers, therefore of the spatial patterns of the landscape.

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Section: Age Structurementioning

confidence: 99%

Establishment of woody plants in Mediterranean old fields: opportunity in space and time

Debussche

Lepart

1992

Landscape Ecol

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“…In this study, percentage germination increased as the duration of soak in water or 10 µM fluridone increased from 1 to 12 h. This effect suggests the presence of an endogenous growth inhibitor, possibly abscisic acid, that is soluble in water and whose activity is inhibited by fluridone (an inhibitor of Abscisic acid biosynthesis). Abscisic acid (ABA) is long known to leach in water allowing dormant seeds to germinate (Villiers and Wareing, 1960). Also, fluridone has severally been shown to inhibit ABA biosynthesis/ content in seeds and tubers (Zeevaart and Creelman, 1988; Le Page-Degivry et al, 1990; Mulwa and Nwanza, 2006).…”

Section: Discussionmentioning

confidence: 99%

“…Fluridone is a plant growth regulator that is known to induce germination in many plant parts that exhibit dormancy by competitively inhibiting C 40 carotenoid, which is the precursor of abscisic acid (ABA) biosynthesis (Fong et al, 1983;Zeevaart and Creelman, 1988). Also, ABA can leach out of plant tissues soaked in water (Villiers and Wareing, 1960;loveys and Van Dijk, 1988). However, the most effective soak duration in fluridone or water on germination of scarified seeds from immature fruits is not known.…”

Section: Introductionmentioning

confidence: 99%

Germination of Allanblackia floribunda Seeds: The Effect of Soak Duration in Fluridone on Germination and Seedling Growth

Ileleji¹

2015

AFF

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Abstract:Allanblackia seeds contain about 72% white fat (mostly of oleic and stearic acid), with high medicinal and industrial value, but the plant has not been domesticated, so seeds are only gotten from the wild. The demand for seeds of the wild Allanblackia floribunda exceeds supply and efforts to domesticate the plant to increase seed availability have been unsuccessful due to long seed dormancy periods. Soaking scarified seeds from immature fruits in water or fluridone shortened dormancy to less than 3 months, but the effects of different soak durations on germination, dormancy and seedling vigor, are not fully understood. This study aimed to determine the effects of three soak durations (1, 6, and 12 h) in water or fluridone (10 µM or 30 µM) on seed germination and seedling growth. The study was a 3 x 3 factorial experiment arranged in a Completely Randomized Design, using scarified immature seeds. At 16 weeks after treatment, seedlings were transplanted into polypots filled with topsoil and assessed weekly for the effects of treatments on seedling growth (leaf number and plant height). The % germination increased as the duration of soak in water or 10 µM fluridone increased from 1 to 12 h. The tendency to obtain 75-100% germination was higher when seeds were soaked in 10 µM fluridone (i.e., for 6 or 12 h) as compared to soaking in water for up to 12 h. The shortest duration (72 d, i.e., approx. 2.5 months) to achieve >75% germination was when Allanblackia seeds were soaked for 6 h in 10 µM fluridone. Soaking the seeds for 12 h in 10 µM fluridone resulted in 100% germination in 3 months. At transplanting, seedlings from fluridone treated seeds were taller, and had more leaves than those from seeds soaked in water for 1 or 6 h, but the reverse was observed in seedlings from seeds soaked for 12 h in water. However, these effects diminished after 2 weeks, when the seedlings have become established. This study has shown a promising method for achieving rapid and efficient germination of Allanblackia seeds with no noticeable adverse effects on seedling establishment.

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“…Embryos from cold-temperature after-ripened seeds will germinate rapidly when placed in moist chambers at room temperature, while those from untreated seeds show only very limited germination during a 10 day period. In Fraxinits excelsior L., germination of dormant embryos can be indtuced either by leaching or with gibberellic acid, GA3 (11). WVe found that we can prevent germination in nondormant Fraxini(s antericana L.…”

mentioning

confidence: 99%

“…Villiers and \Vare-ing (11) have slhown that the germination behavior of excised embryos from this genus depends on their previous hiistorv. Embryos from cold-temperature after-ripened seeds will germinate rapidly when placed in moist chambers at room temperature, while those from untreated seeds show only very limited germination during a 10 day period.…”

mentioning

confidence: 99%

Abscisic Acid Levels and Seed Dormancy

Sondheimer¹,

Tzou²,

Galson³

1968

Plant Physiol.

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A bstract. Dormant seeds from Fraxinus species require oold-temperature after-ripening prior to germination. Earlier, we found that abscisic acid (ABA) will inhilbit germination of excised nondormant embryos and that this can be reversed with a combination of gibberellic acid and kinetin. Using Milborrow's quantitative "racemate dilution" method the ABA concentration in 3 types of Fraxinus seed and pericarp were determined. While ABA was present in all tisisues, the highest concentration was found in the seed and, perioarp of dormant F. americana. During the chililing treatment of F. americana the ABA levels decreased 37 N% in the pericarp and 68 % in the seed. The ABA concentration of the seed of the nondormant species, F. ornus, is as low as that found in F. americana seeds after cold treatment. Experiments with exogenously adided ABA solutions indicate that it is unlikely that the ABA in the pericarp functions in the regulation of seed dormancy. However, the ABA in the seed does seem to have a regulatory role in germination.Abscisic acid (ABA) (1) has been implicated in the regulation of leaf abscission, senescence, growth inhibition, and bud and seed dormancy. Up to now most of the studies have dealt with effects of exogenously added ABA. The few isolation studies that have been reported do not permit a quantitative correlation between endogenous ABA levels and a change in the physiological state of the test plant.WNe are studying physiological and biochemical aspects of seed germination with dormant and nondormlant Fraxinus (ash) seeds. Villiers and \Vare-ing (11) have slhown that the germination behavior of excised embryos from this genus depends on their previous hiistorv. Embryos from cold-temperature after-ripened seeds will germinate rapidly when placed in moist chambers at room temperature, while those from untreated seeds show only very limited germination during a 10 day period. In Fraxinits excelsior L., germination of dormant embryos can be indtuced either by leaching or with gibberellic acid, GA3 (11). WVe found that we can prevent germination in nondormant Fraxini(s antericana L.aind Fraxinus ormus L. embryos with exogenously added (RS)-ABA. Furthermore the ABA-induced inhibition is partially reversedl by combinations of GA, anid kinetini (9).It is generally accepte(1 thiat resuilts obtained e.xclusively witlh exogenously applied growth substances are insuifficienit to establish a regulatory role for these substances in the intact organism. A minimum requirement for such a role would be to show the presence of the hormones in the intact plant and to demonstrate a correlation between hormonal concentration levels and physiological states. With the elegant "racemate dilution" method developed by Miliborrow (7) it is now possible to obtain quantitative values for the ABA concentration in plants. With

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Interaction of Growth Inhibitor and a Natural Germination Stimulator in the Dormancy of Fraxinus excelsior L.

Cited by 65 publications

References 2 publications

Establishment of woody plants in Mediterranean old fields: opportunity in space and time

Establishment of woody plants in Mediterranean old fields: opportunity in space and time

Germination of Allanblackia floribunda Seeds: The Effect of Soak Duration in Fluridone on Germination and Seedling Growth

Abscisic Acid Levels and Seed Dormancy

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