scholarly journals Germinación de Chiranthodendron pentadactylon Larr. (Sterculiaceae), en respuesta a la escarificación, temperatura y luz

2017 ◽  
pp. 5
Author(s):  
Reyna Osuna-Fernández ◽  
Guillermo Laguna-Hernández ◽  
Alicia Brechú-Franco ◽  
Alma Orozco-Segovia
Keyword(s):  
Seed Germination ◽  
Seed Coat ◽  
White Light ◽  
Maternal Effect ◽  
Seed Quality ◽  
Variable Temperature ◽  
Red Light ◽  
Seed Viability ◽  
Weather Conditions ◽  
Two Populations

Seed quality and seed germination with scarification and non scarification and variable temperature and light were determined in Ch. pentadactylon seeds form two places of Guerrero and Oaxaca. Also seed viability was determined in seeds from Guerrero stored 6 months at 5º C. Seeds showed to be orthodox and dormant due to an impervious seed coat. The seeds from Guerrero had higher weight, length and water content than those from Oaxaca, however the scarified seeds from Oaxaca reached a higher germination percentages. Germination of scarified seeds of the two populations was enhanced by alternated temperatures and inhibited by far red light. Germination under darkness, red light and white light did not differ significantly. In soil some seeds could be dormant under a low ratio red:far red light transmitted by litter. The differences between the two populations might be due to a maternal effect induced by weather conditions in their geographic localities.

Physical dormancy in seeds of Dodonaea viscosa (Sapindales, Sapindaceae) from Hawaii

2004 ◽  
Vol 14 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Jerry M. Baskin ◽  
Barbara H. Davis ◽  
Carol C. Baskin ◽  
Sean M. Gleason ◽  
Susan Cordell
Keyword(s):  
Seed Coat ◽  
White Light ◽  
Red Light ◽  
Dodonaea Viscosa ◽  
Physical Dormancy ◽  
Critical Moisture Content ◽  
Temperature Regimes ◽  
Wide Range ◽  
Critical Moisture ◽  
Impermeable Seed Coat

Dormancy in seeds ofDodonaea viscosais due to a water-impermeable seed coat (physical dormancy, PY). Thus, mechanically scarified seeds imbibed water (c.95% increase in mass) and germinated to high percentages over a wide range of temperature regimes in both white light and darkness, whereas non-scarified seeds did not take up water. Dry heat at 80–160°C and dipping in boiling water for 1–60 s also broke dormancy in a high percentage of the seeds, and continuous far-red light was not inhibitory to germination. However, dry storage in the laboratory for >1 year did not overcome dormancy. Seeds made water-permeable by boiling imbibed water, and thus germinated, at a much slower rate than those made water-permeable by mechanical scarification. We suggest that boiling opened the ‘water gap’ in the seed coat (not yet described inSapindaceaebut present in other taxa with PY) and that water entered the seed only through this small opening, thereby accounting for the slow rate of imbibition and subsequent germination. Physical dormancy has now been shown to occur in seeds of this polymorphic, worldwide species from Australia, Brazil, Hawaii, Mexico and New Zealand. The low level of dormancy reported for seed lots ofD. viscosain China, India and Pakistan is probably due to collection of seeds before they dried to the critical moisture content for development of water-impermeability of the seed coat. Germination of non-dormant seeds over a wide range of temperatures and in white light, far-red (leaf-canopy shade) light and darkness are part of the germination strategy ofD. viscosaand of other taxa whose seeds have PY at maturity.

scholarly journals Germination and seed conservation of a pioneer species, Tecoma stans (Bignoniaceae), from tropical dry forest of Colombia

2018 ◽  
Vol 66 (2) ◽  
pp. 918
Author(s):  
Jhon Alexander Vargas-Figueroa ◽  
Alba Marina Torres-González
Keyword(s):  
Seed Germination ◽  
White Light ◽  
Germination Rate ◽  
Red Light ◽  
Tropical Dry Forest ◽  
Seed Storage ◽  
Dry Forest ◽  
Storage Behavior ◽  
Mean Germination Time ◽  
Seed Storage Behavior

Seed germination and seed longevity under different environmental conditions are fundamental to understand the ecological dynamics of a species, since they are decisive for its success within the ecosystem. Taking this into account, seed germination and seed storage behavior of a pioneer species of tropical dry forest (Tecoma stans) were studied in the laboratory, to establish the effect of different environmental conditions on a local tree population. Two seed lots collected in July 2011, from Cali (Colombia), were evaluated under three alternating temperatures (20/30, 20/25, 25/30 ºC; 16/8 h) and four light qualities (12-hour white light photoperiod, darkness, and 15 minutes of red light -R and far red light -FR). Final germination was recorded for all treatments; for white light treatment the daily germination was recorded to calculate mean germination rate, mean germination time, and two synchronization indices. To assess the effect of light quality on physiological variables, a destructive germination test was carried out. For this test, another seed lot was evaluated under the same light conditions using an alternating temperature of 20/30 °C - 16/8 h, recording germination during six days for every treatment. In addition, seeds were stored at two different moisture contents (7.7, 4.1 %) and three storage temperatures (20, 5, -20 ºC), during two time periods (one and three months); a seed germination test was conducted for each treatment. Four replicates of 35 seeds per treatment were used for all experiments. Germination was high (GP > 90 %) with all alternating temperatures under white light, whereas under R, FR, and darkness germination was evenly successful at low temperatures, but at higher temperature, half of the seeds entered into secondary dormancy (GP= 45-65 %). However, mean germination rate and synchronization under R and FR decreased significantly in comparison to white light treatment and, consequently, mean germination time increased. Seed storage behavior of this species is orthodox due to the high germination (GP > 90 %) obtained under all treatments. In conclusion, T. stans seeds have a negative germination response at high incubation temperatures in the absence of white light, entering into a secondary dormancy. In contrast, an environment with a lower temperature and without white light delays the germination, but at the end seeds are able to reach the same germination values. This seed dependence on incident light in limiting conditions suggests a physiological mechanism on the seed tissues of this species, probably mediated by phytochromes. Finally, the orthodox seed storage behavior of T. stans is a reason to include this species in ex situ seed conservation programs for restoration and recovery of the tropical dry forest; however, long-term studies should be conducted in order to evaluate the maintenance of this characteristic throughout longer periods of time. Rev. Biol. Trop. 66(2): 918-936. Epub 2018 June 01. 

scholarly journals Germination responses of seeds of Desmodium triflorum

2018 ◽  
Vol 4 (2) ◽  
pp. 19 ◽  
Author(s):  
Niroj Paudel ◽  
Prakash Deep Rai
Keyword(s):  
Seed Germination ◽  
Blue Light ◽  
White Light ◽  
Red Light ◽  
Light Condition ◽  
Dark Condition ◽  
Percentage Germination ◽  
Negative Effect

<p class="abstract"><strong>Background:</strong> Germination of <em>Desmodium triflorum</em> is used for the scarification using the acid is valuable for the different light condition.</p><p class="abstract"><strong>Methods:</strong> The sample was collected as four month of interval of time and the seed is treated with acids with different time.  </p><p class="abstract"><strong>Results:</strong> seeds scarified with sulfuric acids for 10 min before sowing had better germination than those scarified for 5 and 15 min. Among them light qualities, red and white light had slightly promoted effect whereas blue light and dark condition had slightly negative effect on seed germination.</p><p><strong>Conclusions:</strong> In comparison to blue light and dark condition, red light and white light were promoted to percentage germination indicating the role of phytochrome in seed germination of <em>Desmodium triflorum</em>. </p>

UJI VIABILITAS TERHADAP BENIH POLYEMBRIONI

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Jasmi Jasmi
Keyword(s):  
Seed Germination ◽  
Seed Coat ◽  
Seed Viability ◽  
Embryo Sac ◽  
Dry Weight ◽  
Food Storage ◽  
Number Of Leaves ◽  
Citrus Seed ◽  
Food Reserves ◽  
Germination And Growth

Seeds are mature ovules. One or more of the ovaries formed in the legume, but never more than one seed formed in the ovaries of monocots. Each ripe seed always consists of at least two parts, namely: (1) Embryo, (2) Seed coat (Seed coat or testa). Embryo is formed or derived from fertilized eggs (zygote) by undergoing cell division in the embryo sac. Seed coat is formed from the integument (one or more) of the ovules. In legumes generally there are two layers of seed coat. Every very young and growing seed always consists of three parts: (1) Embryo, (2) seed coat, (3) Endosperm. Endosperm is a storage food storage network which is absorbed by the embryo before or during seed germination and is always present in very young seeds. Polyembryonics is the presence of more than one embryo in one seed, but these embryos do not always mature or mature, remain undeveloped or degenerate. The purpose of this research is to study the germination of one seed that has more than one embryo and to determine the growth of seedlings from polyembryonic seeds. The results showed that the highest plant growth (plant height, number of leaves, fresh weight and dry weight of orange seeds) was found in orange seeds that had 1 embryo compared to orange seeds which had 2 and 3 embryos. Seed germination and growth is strongly influenced by the amount of food reserves stored in seeds (Magagula and Ossom 2011 in Hasnah M, 2013). Keywords: Citrus Seed, Polyembrioni, Seed Viability

scholarly journals Ecophysiology of seed germination in Mediterranean geophytes. 1. Muscari spp

2002 ◽  
Vol 12 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Maria A. Doussi ◽  
Costas A. Thanos
Keyword(s):  
Seed Germination ◽  
White Light ◽  
Mediterranean Climate ◽  
Germination Rate ◽  
Red Light ◽  
Rainfall Regime ◽  
Light Conditions ◽  
Rainy Period ◽  
Germination Characteristics ◽  
The Mediterranean

Ecophysiological aspects of seed germination were investigated in four Mediterranean geophytes of the genus Muscari (Liliaceae): M. comosum (tassel hyacinth), M. neglectum (common grape hyacinth), M. commutatum and M. weissii. Experiments were performed at constant temperatures in the dark and under temperature and light conditions simulating those prevailing in nature during November–January, i.e. well into the rainy season of the Mediterranean climate. In all species, no primary dormancy was revealed, and germination occurred in a rather narrow range of cool temperatures (optimum at 10 or 15°C) and at a remarkably slow rate; both germination characteristics seem to be associated with autumn/winter seed germination and seedling establishment. Such a postulated strategy is ecologically advantageous within an unpredictable rainfall regime, known to prevail during the start of the rainy period of the Mediterranean climate. This strategy may also explain the spread of germination of M. comosum seeds over two consecutive years, observed by Theophrastus. Far-red light, simulating light conditions under a dense canopy, resulted in only a slight delay of germination compared to dark controls. Diurnal white light, qualitatively simulating natural daylight, caused a significant decrease of the germination rate in all four species studied. Moreover, white light was found to suppress considerably final seed germination (photoinhibition) in M. weissii and M. neglectum; in the latter species, prolonged imbibition under white light also led to the induction of secondary dormancy.

scholarly journals Quality assessment of Urochloa (syn. Brachiaria) seeds produced in Cameroon

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Njehoya Clémence-Aggy ◽  
Ntchapda Fidèle ◽  
Kana Jean Raphael ◽  
Etchu Kingsley Agbor ◽  
Sita R. Ghimire
Keyword(s):  
Seed Germination ◽  
Quality Assessment ◽  
Seed Quality ◽  
Seed Viability ◽  
Quality Parameters ◽  
North West ◽  
Grass Seed ◽  
Significant Relationships ◽  
Livestock Farmers

AbstractUrochloa (syn. Brachiaria) is the most popular fodder of livestock farmers in Cameroon for hay and seed productions. Farmers in Cameroon have been producing Brachiaria seeds for decades for own uses and surplus are sold to neighbours, and to traders from Cameroon and neighbouring countries. However, there is no information available about qualities of these seeds. Fifteen Urochloa seeds samples were collected from farmers and/or government stations in five regions (Adamaoua, East, North, North West, and West) and analysed for major seed quality parameters along with seeds of improved Urochloa cultivar Basilisk imported from Brazil as a check. Study showed significant differences among treatments for various seed quality parameters tested (P < 0.0001). The highest thousand grains weight was recorded in Basilisk (5.685 g), followed by W12 (3.555 g), A05 (3.153 g) and N01 (2.655 g). Caryopsis number and caryopsis weight were highest in Basilisk followed by E09, A06, and W12. Of three conditions tested for seed germination, mean germination was the highest in greenhouse (7.39%) where Basilisk had the highest germination (25.5%) followed by N01 (18.50%), A05 (14.50%) and W12 (12.75%). The seed viability ranged from 18% (E09) to 81% (N01), and there were a positive and highly significant relationships between seed germination and viability traits (r = 0.883; P < 0.0001). This study showed a marked difference in seed quality parameters of Urochloa grass seeds produced in Cameroon, and the potential of developing Urochloa grass seed business in the Northern, Adamaoua and Western regions of Cameroon.

scholarly journals Seed germination of Carex lainzii Luceño, E. Rico & T. Romero: An endemic Spanish endangered species

2019 ◽  
Vol 20 (3) ◽  
pp. 704-711
Author(s):  
KAROLINE APARECIDA FELIX RIBEIRO ◽  
CRISTIAN MADEIRA DE MEDEIROS ◽  
JOSÉ ÁNGEL SÁNCHEZ-AGUDO ◽  
JOSÉ SÁNCHEZ-SÁNCHEZ
Keyword(s):  
Seed Germination ◽  
Endangered Species ◽  
Ex Situ Conservation ◽  
Seed Viability ◽  
Potassium Nitrate ◽  
Ex Situ ◽  
Cold Stratification ◽  
Different Temperatures ◽  
Two Populations

Abstract. Ribeiro KAF, Madeira de Medeiros C, Agudo JAS, Sánchez JS. 2019. Seed germination of Carex lainzii Luceño, E. Rico & T. Romero: An endemic Spanish endangered species. Biodiversitas 20: xxxx. Strategies to halt the decline of biodiversity include: in-situ and ex-situ conservation, the latter already considered at the global level essential in conservation programs. The results of the germinative responses of Carex lainzii Luceño, E. Rico & T. Romero (Cyperaceae), an endemic Spanish endangered species, are presented in this work, to different trials carried out in the laboratory with seeds harvested in the two known populations of that community. Treatments with and without 0.2% potassium nitrate (KNO3) were tested for four, six and eight months in cold stratification at 5 °C in two germination chambers at different temperatures (22/10 °C and 27/15 °C with a photoperiod of 12/12 hours). The results indicate that there is a large difference in germination rates between the two populations. The use of KNO3 did not increase germination rates in any case, but differences were found between periods of cold stratification, with six months being the most effective. On the other hand, the germination rates of both populations remain low (17.58% and 2%) compared to the obtained rate of seed viability. With this first approach to the understanding of the germination requirements of C. lainzii, it becomes clear that new essays are needed to obtain better results, in order to effectively implement the protection plans of C. lainzii populations.

scholarly journals Determining Seed Viability During Fruit Maturation to Improve Seed Production and Availability of New Citrus Rootstocks

2021 ◽  
Vol 12 ◽  
Author(s):  
Deived Uilian de Carvalho ◽  
Daniel A. Boakye ◽  
Tim Gast ◽  
Rui Pereira Leite Junior ◽  
Fernando Alferez
Keyword(s):  
Seed Germination ◽  
Seed Quality ◽  
Seed Viability ◽  
Growing Seasons ◽  
Seed Supply ◽  
Germination Potential ◽  
Citrus Groves ◽  
Citrus Rootstock ◽  
Physiological Quality

In recent years, the pressure for replanting and resetting huanglongbing (HLB or citrus greening) affected citrus groves has led to an inadequate seed supply for the most popular rootstock cultivars in the State of Florida, United States. Early fruit harvesting of citrus rootstock source trees might reduce fruit losses and enhance seed availability, especially in HLB-endemic and hurricane susceptible areas, if the physiological quality of the seeds is adequate. The effects of fruit maturity on seed quality and seedling performance of US-802, US-897, and US-942 citrus rootstocks were investigated for two consecutive growing seasons. The study included the evaluation of seed germination and nursery performance of the citrus rootstock seedlings. The germination test was performed in vitro, where seeds were hand-peeled, surface-sterilized and placed in culture tubes containing basal Murashige and Skoog medium. For the emergence test, seeds were sown in seedling trays containing sterilized growing substrate in a greenhouse with controlled-environment conditions. Rootstock fruits from all three varieties harvested in August and September had seeds with higher germination potential, as more than 90% of the seeds generated seedlings. US-942 had more % of emergence than US-802 and US-897, resulting in faster seed germination; in contrast, US-802 had the faster shoot growth rate. Assays on fruit abscission response showed that by August, fruit from all three varieties were responsive to ethylene and abscised, although response varied and was higher in US-942, suggesting the seeds were mature enough. Taken together, our findings indicate that fruits these three rootstocks can be harvested as early as August in contrast to the current procedures without losing germination potential. This will result in an increase in available seeds for nurseries in Florida.

Effect of temperature and light on seed germination of Erysimum naxense and Erysimum krendlii

2013 ◽  
Vol 8 (12) ◽  
pp. 1194-1203 ◽  
Author(s):  
Paraskevi Gkika ◽  
Nikos Krigas ◽  
George Menexes ◽  
Ilias Eleftherohorinos ◽  
Eleni Maloupa
Keyword(s):  
Seed Germination ◽  
Ex Situ Conservation ◽  
Red Light ◽  
Seed Viability ◽  
Ex Situ ◽  
Effect Of Temperature ◽  
Natural Habitats ◽  
Experimental Conditions ◽  
Light Regimes ◽  
Species Specific

AbstractSeed germination of two local Greek endemics was studied (Erysimum naxense, Erysimum krendlii). Seed viability was determined by using the tetrazolium method and germination was studied in synchronized cycles of five and four alternating temperatures [10/5 (for E. naxense only) and 15/10, 20/15, 25/20, and 30/25°C for both species, in cycles of 16 h day/8 h night], and in five light regimes (red, blue, green, white, and dark). Germination of E. naxense and E. krendlii seeds was determined daily for six and five weeks, respectively, with the data analyzed as viability adjusted accumulative seed germination at the end of each week. E. naxense’s seed viability was higher (90%) than that of E. krendlii (64%); seed germination (%) of both increased at low alternating temperatures (10/5°C, 15/10°C, 20/15°C). Germination of E. naxense seeds at low temperatures was light-independent, whereas at high temperatures it was increased with red light. Germination of E. krendlii seeds was inconsistently affected by light at the temperatures studied. Percentages of seed germination of both species were higher in experimental conditions similar to the ones of their natural habitats during autumn and/or spring (facilitated with Geographic Information Systems). These conclusions provide guidelines for species-specific propagation protocols and ex situ conservation.

scholarly journals Light and Phytochrome Involvement in Rosa multiflora Seed Germination

1995 ◽  
Vol 120 (6) ◽  
pp. 953-955 ◽  
Author(s):  
Yoshiko Yambe ◽  
Kiyotoshi Takeno ◽  
Takashi Saito
Keyword(s):  
Seed Germination ◽  
White Light ◽  
Red Light ◽  
Germination Percentage ◽  
Rosa Multiflora ◽  
Light Effect ◽  
Complete Darkness ◽  
Subsequent Exposure ◽  
Multiflora Rose

Seed germination percentage of multiflora rose (Rosa multiflora Thunh.) was much higher under continuous white light than in complete darkness. Red light was the most effective in inducing germination, and far-red light was ineffective. Exposure to red light for 1 min increased germination; this effect was saturated at an exposure of2 min. The red-light effect was reversed by subsequent exposure to far-red light. The results indicate that rose seeds are positively photoblastic, and that the photoreceptor involved is most likely phytochrome.

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