scholarly journals Effect of stratification and gibberellic acid on epicotyl dormancy release in seeds of Yunnanopilia longistaminea (Opiliaceae)

Author(s):  
Guan-song Yang ◽  
Liu Yang ◽  
Yue-hua Wang ◽  
Shi-kang Shen

Yunnanopilia longistaminea is an endangered monotypic species belonging to Opiliaceae. This edible plant is an important germplasm source with a high economic value in China. The seed dormancy and germination of Opiliaceae species have been rarely investigated. This study examined the effects of scarification, soaking in gibberellic acid, and dehydration on the seed germination of Y. longistaminea. Results indicated that the seed germination of this species involves two stages: radicle emergence and epicotyls (shoot) emergence. During radicle emergence, the optimum temperatures were 28 °C and 28 °C/20 °C. Seed moisture content and viability decreased as dehydration occurred. Thus, the seeds may be recalcitrant. The optimum GA3 solution for the seeds undergoing shoot emergence was 100 mg·L−1. The percentages of shoot emergence in 7 and 14 days of stratification at 5 °C were slightly higher than those in other groups. This study is the first to describe epicotyl dormancy in Y. longistaminea seeds. From the seed grow to the seedling of Y. longistaminea subjected to a autumn→winter→spring temperature process in nature conditions. Warm and cold stratification can alleviate radicle and epicotyl dormancy, respectively. The duration of cold stratification also significantly affects the epicotyl dormancy release of Y. longistaminea. The researches on the seeds breaking methods: warm(28°C/20°C)→cold(5°C)→GA3(100mg·L−1)→warm(28°C/20°C).

2016 ◽  
Author(s):  
Guan-song Yang ◽  
Liu Yang ◽  
Yue-hua Wang ◽  
Shi-kang Shen

Yunnanopilia longistaminea is an endangered monotypic species belonging to Opiliaceae. This edible plant is an important germplasm source with a high economic value in China. The seed dormancy and germination of Opiliaceae species have been rarely investigated. This study examined the effects of scarification, soaking in gibberellic acid, and dehydration on the seed germination of Y. longistaminea. Results indicated that the seed germination of this species involves two stages: radicle emergence and epicotyls (shoot) emergence. During radicle emergence, the optimum temperatures were 28 °C and 28 °C/20 °C. Seed moisture content and viability decreased as dehydration occurred. Thus, the seeds may be recalcitrant. The optimum GA3 solution for the seeds undergoing shoot emergence was 100 mg·L−1. The percentages of shoot emergence in 7 and 14 days of stratification at 5 °C were slightly higher than those in other groups. This study is the first to describe epicotyl dormancy in Y. longistaminea seeds. From the seed grow to the seedling of Y. longistaminea subjected to a autumn→winter→spring temperature process in nature conditions. Warm and cold stratification can alleviate radicle and epicotyl dormancy, respectively. The duration of cold stratification also significantly affects the epicotyl dormancy release of Y. longistaminea. The researches on the seeds breaking methods: warm(28°C/20°C)→cold(5°C)→GA3(100mg·L−1)→warm(28°C/20°C).


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3435 ◽  
Author(s):  
Guan-song Yang ◽  
Liu Yang ◽  
Yue-hua Wang ◽  
Shi-kang Shen

Yunnanopilia longistamineais an endangered monotypic species belonging to Opiliaceae. This edible plant is an important germplasm source with a high economic value in China if propagation were less difficult. Seed dormancy and germination of this species were investigated to improve propagation. Considering seeds have a fully developed embryo and mature and are dispersed in summer, and radicles and epicotyls emerge the following autumn and next spring, respectively, we hypothesized thatY. longistamineaseeds may undergo physiological epicotyl dormancy. Seed moisture content and viability decreased as dehydration occurred. Thus, the seeds may be recalcitrant. The seed germination of this species involves two stages: radicle emergence and epicotyl (shoot) emergence. The optimum temperature was 28 °C and 28 °C/20 °C to radicle emergence. The optimum GA3solution for the seeds undergoing shoot emergence was 100 mg L−1. The percentages of shoot emergence in seven and 14 days stratification at 5 °C were slightly higher than those in other groups. This study is the first to describe physiological epicotyl dormancy inY. longistamineaseeds. Under natural conditions, seeds are subjected toY. longistamineaa autumn → winter → spring temperature. Warm moist conditions and cold stratification can improve radicle emergence and alleviate epicotyl dormancy, respectively. The duration of cold stratification also significantly affects the epicotyl dormancy release ofY. longistaminea. Optimal dormancy breakage methods are warm (28 °C/20 °C) → cold (5 °C) → GA3(100 mg L−1) → warm (28 °C/20 °C).


Botany ◽  
2017 ◽  
Vol 95 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Danping Song ◽  
Ganesh K. Jaganathan ◽  
Yingying Han ◽  
Baolin Liu

There are several different opinions regarding dormancy in tea (Camellia sinensis L.), but there is no strong evidence available to conclude whether or not these seeds are dormant. Freshly matured tea seeds collected from Hangzhou, China, at the natural dispersal time did not germinate in light at daily alternative temperature regimes of 10/15, 15/20, 20/25, or 25/35 °C, or at a constant temperature of 25 °C. Seeds were permeable to water and the embryos did not grow prior to radicle emergence, thus, the seeds have no physical, morphological, or morphophysiological dormancy. When cold-stratified at 4 °C for 1, 2, and 3 months, 64%, 88%, and 93% of the seeds germinated, respectively. Intact fresh seeds failed to germinate after treatment with 0, 10, 500, and 1000 ppm GA3, whereas 3%, 4%, 61%, and 86% of cracked seeds germinated, respectively. Thus, the seeds have nondeep and intermediate physiological dormancy. Seeds cold-stratified for 2 months that were buried at soil depths of 0, 1, and 5 cm in pots showed that seeds at 1 cm depth established significantly higher number of seedlings (P < 0.05) than at other two depths. Because tea seeds are susceptible to summer temperature drying, these seeds do not establish a persistent seed bank.


2008 ◽  
Vol 18 (4) ◽  
pp. 213-222 ◽  
Author(s):  
Andrea Mondoni ◽  
Robin Probert ◽  
Graziano Rossi ◽  
Fiona Hay ◽  
Costantino Bonomi

AbstractAlthough various aspects of the biology of Anemone nemorosa have been examined, few studies present data on seed germination, and even then information tends to be rather contradictory. A. nemorosa L. is a spring-flowering, woodland geophyte, widely distributed across much of Europe. Germination phenology, including embryo development and radicle and shoot emergence, were investigated in one mountain and three lowland populations from northern Italy. Immediately after harvest, seeds were either sown on agar in the laboratory under simulated seasonal temperatures, or placed in nylon mesh sachets and buried in the wild. Embryos, undifferentiated at the time of dispersal, grew under summer conditions in the laboratory and in the wild. However, seeds did not germinate under continuous summer conditions. Radicle emergence in the field was first recorded at the beginning of autumn, when soil temperatures had dropped to c. 15°C in the case of the three lowland populations, and to c. 10°C at the mountain site. Shoot emergence was delayed under natural conditions until late autumn/early winter, when soil temperatures had dropped to c. 10°C in the lowlands and c. 6°C at the mountain site. In the laboratory, a period of cold stratification was required for shoot emergence, and this requirement was more pronounced in the mountain population. Seeds of the mountain population completed embryo development, radicle emergence and shoot emergence at cooler temperatures compared with the lowland populations. These results suggest that germination in A. nemorosa is highly adapted and finely tuned to local climate. We conclude that seeds of A. nemorosa display deep, simple epicotyl, morphophysiogical dormancy, and this is the first report of such dormancy for the genus Anemone. However, the continuous development and growth of embryos from the time of natural dispersal, and the lack of evidence of developmental arrest under natural conditions, suggests that radicles are non-dormant.


2019 ◽  
Vol 49 ◽  
Author(s):  
Ángel Cabello ◽  
Nicolás Espinoza ◽  
Sergio Espinoza ◽  
Antonio Cabrera ◽  
Rómulo Santelices

Background: Nothofagus glauca (Phil.) Krasser (Nothofagaceae, “Hualo”) is an endemic tree of the Mediterranean zone of Chile. The natural forests in this area have been severely fragmented as a result of human causes such as replacement by agricultural crops and fast-growing tree species. From 1975, these forests have declined from 900,000 ha to 145,000 ha, so it is categorised on the IUCN Red List as ‘vulnerable’. In restoring this ecosystem, efforts should focus, in part, on the propagation of quality stock. However, information on propagation systems is still insufficient. Methods: We aimed to analyse the effect of different pre-germinative treatments and sowing times on seed germination, and seedling growth and quality. The pre-germinative treatments were: (i) cold stratification; (ii) soaking in gibberellic acid (GA3) and thiourea solution; and (iii) nursery cultivation, while the sowing times were July, August and September. Results: A high germination capacity was achieved by: soaking the seeds in GA3 solution irrespective of concentration; stratifying, irrespective of period; or soaking in 7.5 mg L-1 thiourea solution, values significantly varied from that of the control treatments. The sowing time was not relevant in terms of the percentage of germination or seedling development. Stratification at 5°C for 60 days produced the best quality indices for N. glauca seedlings but no significant differences were found in any of the morphological attributes tested as a result of the pre-germinative treatments. Conclusions: The pre-germinative treatments significantly improved the germination and seedlings growth of N. glauca. Cold stratification at 5°C for 60 days is recommended as it produced suitable seedlings for field establishment. Gibberellic acid and thiourea did not produce important effects on seedling growth. Our results suggest the presence of endogenous physiological dormancy of the N. glauca seeds. The results of this study provide important information on propagation and nursery techniques of N. glauca, which can be used in restoration programmes.


2021 ◽  
pp. 1-7
Author(s):  
Shun-Ying Chen ◽  
Chiung-Pin Liu ◽  
Carol C. Baskin ◽  
Ching-Te Chien

Abstract Viburnum is a temperate-zone genus that also occurs in mountains of South America and Malesia, and seeds of many species have morphophysiological dormancy (MPD). Information on the level of MPD in seeds of species in various clades of Viburnum potentially would increase our understanding of the evolutionary relationships between the nine levels of MPD. Our aim was to determine the level of MPD in seeds of Viburnum plicatum var. formosanum that is endemic to mountains (1800–3000 m a.s.l.) in Taiwan and a member of the Lutescentia clade. The temperature requirements for embryo growth and root and shoot emergence and response of seeds to gibberellic acid (GA) were determined. No fresh seeds germinated during 16 weeks of incubation at 15/5, 20/10, 25/15, 30/20 or 25°C. Embryo growth and root emergence occurred during moist cold stratification at 5°C or at a temperature sequence of 15/5 to 5°C. During cold stratification, embryos length increased from 0.76 ± 0.06 to 3.40 ± 0.26 mm and the embryo length:seed length ratio from 0.20 ± 0.02 to 0.68 ± 0.07. In a temperature sequence simulating field conditions, embryos grew inside seeds at 5°C, roots emerged at 15/5°C and shoots emerged at 20/10°C. The optimum temperature for embryo growth was 5°C. Neither GA3 nor GA4 was effective in promoting root emergence. We conclude that seeds of V. plicatum var. formosanum have deep complex MPD, which is a first report for Viburnum. Dormancy release during the cool season at high elevations helps to ensure that seeds germinate at the beginning of the warm season.


2010 ◽  
Vol 20 (2) ◽  
pp. 109-121 ◽  
Author(s):  
José M. Herranz ◽  
Miguel Á. Copete ◽  
Pablo Ferrandis ◽  
Elena Copete

AbstractSeeds of Aconitum napellus subsp. castellanum were physiologically dormant at maturity in early autumn, with underdeveloped embryos. Thus they have morphophysiological dormancy (MPD). Embryos in fresh seeds were on average 1.01 mm long, and they had to grow to 3.60 mm before radicle emergence. Cold stratification at 5°C for 5 months with light enhanced the mean embryo length to 2.73 mm (SE = 0.13) and seed germination to 20%. However, with higher temperatures (15/4, 20/7, 25/10, 28/14 and 32/18°C) embryo growth was small, with no seeds germinating. Optimal germination was achieved after 4 months of cold stratification at 5°C followed by incubation at 20/7°C for 1 month with light, when germination ranged between 70 and 79%, depending on seed age, locality and year of collection. Cold stratification could be substituted by the application of GA3 solution, since mean embryo length in seeds incubated at 25/10°C for 1 month with light was 3.52 mm and the germination was 80%. Since cold stratification was the only requirement for the loss of MPD, the longest embryo growth occurred during this treatment, and GA3 promoted MPD loss, we concluded that A. napellus seeds have intermediate complex MPD. Germination was higher in 4-month stored than in freshly matured seeds. A pronounced variability in germinative patterns at inter-annual and inter-population level was recorded.


2016 ◽  
Vol 26 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Yasoja S. Athugala ◽  
K.M.G. Jayasuriya ◽  
A.M.T.A. Gunaratne ◽  
Carol C. Baskin

AbstractTo increase our knowledge of the diversity of seed dormancy and germination in Rubiaceae, we investigated seed desiccation sensitivity and germination of threePsychotriaspecies. Seeds ofP. gardneri, P. nigraandP. zeylanicagerminated to high percentages at <15% seed moisture content. Intact seeds ofP. zeylanicaandP. nigraimbibed water and thus do not have physical dormancy. More than 50% of the seeds ofP. zeylanica, P. nigraandP. gardneritook 33, 53 and 110 d, respectively, at 25°C for the radicle to emerge, and embryo growth occurred before and after radicle emergence. Thus, seeds have morphophysiological dormancy. Shoot emergence ofP. nigraandP. zeylanicaseeds was delayed 50 and 80 d after radical emergence, respectively; thus, seeds have epicotyl morphophysiological dormancy (eMPD). This is the first report of eMPD in Rubiaceae. Since warm stratification promoted both radicle and shoot emergence in seeds ofP. zeylanicaandP. nigra, the level of eMPD is non-deep simple. Hence, dormancy of the studiedPsychotriaspp. can be described as C1bBb(radicle)–C1bBb(epicotyl), i.e. the embryo is underdeveloped and grows prior to radicle emergence and epicotyl emergence under warm temperatures (Bb), and both the radicle and epicotyl have non-deep simple physiological dormancy broken by warm temperatures (C1b). In twoPsychotriaspecies studied in detail, radicle emergence occurs at the beginning of the rainy season and plumule emergence at the peak rainy season when conditions are most favourable for rapid seedling development.


2003 ◽  
Vol 13 (1) ◽  
pp. 17-34 ◽  
Author(s):  
Gerhard Leubner-Metzger

Abstractβ-1,3-Glucanase (βGlu) expression in seeds plays important roles in the regulation of seed germination, dormancy and in the defence against seed pathogens. A thick β-1,3-glucan layer is typical for the seed envelope of cucurbitaceous species, confers seed semipermeability and is degraded during germination. In many species with coat-imposed dormancy, the seed envelope confers a physical constraint to radicle emergence. In the solanaceous species, the micropylar endosperm and testa have this function, and endosperm weakening appears to be a prerequisite for germination. Class I βGlu is transcriptionally induced in the micropylar endosperm of tobacco, tomato and other solanaceous seeds just prior to radicle emergence. βGlu induction and germination are tightly linked in response to plant hormones and environmental factors, e.g. they are both promoted by gibberellins and inhibited by abscisic acid (ABA). Sense and antisense transformation of tobacco reveals two sites of βGlu action: after-ripening-mediated release of testa-imposed dormancy and endosperm rupture during germination. The use of an ABA-inducible chimeric sense-transgene resulted in overexpression of class I βGlu in seeds and provided direct evidence that βGlu contributes to endosperm rupture. A model integrating βGlu, seed dormancy, after-ripening and germination is presented, and possible mechanisms for βGlu action are discussed. It is proposed that βGlu not only helps defend seeds against pathogens, but is also a key factor in regulating coat-imposed dormancy and germination of seeds in response to environmental and hormonal cues.


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