Morphophysiological dormancy in seeds ofConvallaria keiskeiand a proposal to recognize two types of double dormancy in seed dormancy classification

2015 ◽  
Vol 25 (2) ◽  
pp. 210-220 ◽  
Author(s):  
Tetsuya Kondo ◽  
Mizuki Narita ◽  
Shyam S. Phartyal ◽  
Siti N. Hidayati ◽  
Jeffrey L. Walck ◽  
...  

AbstractConvallariamajalishas double dormancy and hypogeal germination, but no information is available on embryo growth or on the effects of light and gibberellic acid (GA3) on germination in this genus. Therefore, we investigated embryo growth and other germination features in seeds ofC. keiskeiand compared the data with those ofTrillium camschatcensein another study. Until now, in seeds with double dormancy, embryo growth and germination (epigeal) have been studied in detail only for seeds ofT. camschatcense. Phenology of embryo growth and emergence of cotyledonary petiole/root (hereafter root) and shoot in seeds ofC. keiskeiwere monitored outdoors. Effects of temperature, light and GA3on embryo growth and root and shoot emergence were tested under laboratory conditions. Roots emerged the first spring following seed dispersal in autumn. The embryo grew soon after root emergence, and germination was hypogeal. Seeds with an emerged root formed buds from which a shoot (leaf) emerged above ground during the second spring. Alternating temperatures and light had negative effects on root emergence, and GA3did not substitute for cold stratification in root emergence. Seeds ofC. keiskeihave double dormancy, but it differs from that inT. camschatcense. Based on differences in embryo growth before (T. camschatcense) versus after (C. keiskei) root emergence, and on epigeal (T. camschatcense) versus hypogeal (C. keiskei) germination, we suggest that two types of deep simple double morphophysiological dormancy (MPD) be recognized. Since embryo growth inC. keiskeidoes not fit the standard definition of MPD, we propose to expand this definition.

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.


Botany ◽  
2021 ◽  
Author(s):  
Ganesh K. Jaganathan ◽  
Narangua Bayarkhuu ◽  
LanLan He ◽  
Baolin Liu ◽  
Jiajin Li ◽  
...  

Beyond strong inference that most of the 2600 known species of Arecaceae produce diaspores with an underdeveloped embryo and therefore have morphological (MD) or morphophysiological dormancy (MPD), little is known about the specific dormancy class or sub-class, and how dormancy-break occurs under ecological conditions. Here, we found that mature seeds of Trachycarpus fortunei collected at the time of natural dispersal had an underdeveloped embryo that was 10% of total seed length. No diaspores germinated over a wide range of temperatures in either light or darkness. Cold-stratification at 4 °C for 1, 2, and 3 months or treatment with 100, 500, and 1000 ppm gibberellic acid (GA3) improved germination percentages, with 3 months cold-stratification or 1000 ppm GA3 resulting in highest germination. The embryo grew inside the seeds during cold-stratification. However, warm stratification did not improve germination. Therefore, seeds of T. fortunei have intermediate complex MPD. Cold stratified seeds moved to spring conditions (15/20 °C) had cotyledonary petiole (CP) elongated, but leaves developed only when the CP elongated seeds were moved to summer temperatures (25/30 °C), suggesting the presence of shoot dormancy. The seedlings are remote-tubular type. This is the first report for Arecaceae indicating the presence of complex MPD.


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.


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).


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).


2000 ◽  
Vol 77 (12) ◽  
pp. 1769-1776 ◽  
Author(s):  
Jeffrey L Walck ◽  
Carol C Baskin ◽  
Jerry M Baskin

Seeds of the eastern North American herbaceous polycarpic perennial Thalictrum mirabile Small have differentiated but underdeveloped (small) embryos that are physiologically dormant at maturity in September. Physiological dormancy was broken effectively by cold stratification at 1°C, but embryos required temperatures [Formula: see text]15:6°C for growth after physiological dormancy was broken. Gibberellic acid substituted for cold stratification. Breaking of physiological dormancy in seeds exposed to natural temperatures in a greenhouse occurred during winter, and embryo growth and germination occurred in late winter - early spring. Furthermore, seeds in the greenhouse remained viable until the second and third (spring) germination seasons. Thus, T. mirabile seeds have the capacity to form a short-lived persistent soil seed bank. Buried seeds of T. mirabile apparently go through an annual dormancy-nondormancy cycle. Seeds buried in September 1994 were nondormant when exhumed in April 1995 and April 1996 and incubated in light at 25:15°C for 2 weeks, but they were dormant in June 1995 and September 1995. Seeds of T. mirabile have nondeep simple morphophysiogical dormancy. This is the first report of nondeep simple morphophysiological dormancy being broken by cold, and not by warm, stratification.


2011 ◽  
Vol 21 (3) ◽  
pp. 215-226 ◽  
Author(s):  
Chia Ju Yang ◽  
Ching-Te Chien ◽  
Yue Ken Liao ◽  
Shun-Ying Chen ◽  
Jerry M. Baskin ◽  
...  

AbstractAlthough mature seeds of the monogeneric conifer family Cephalotaxaceae sensu stricto have underdeveloped embryos, no definitive studies have been done to classify dormancy in this family. Our primary purpose was to determine the kind of dormancy in seeds of Cephalotaxus wilsoniana and to put the results into a broad phylogenetic context for gymnosperms. The species is of horticultural and medicinal value, and information is needed on how to propagate it efficiently from seeds. Embryo growth and germination were monitored for seeds at warm, cold and warm plus cold temperatures, and germination was monitored for seeds subjected to: (1) cold →  warm →  cold →  warm; and (2) warm →  cold →  warm →  cold →  warm temperature sequences. The effects of gibberellic acids GA3 and GA4 were tested on radicle emergence in ungerminated seeds and on shoot emergence in root-emerged seeds. Germination was promoted by ≥ 36 weeks of warm stratification followed by ≥ 8 weeks of cold stratification, but only if seeds were returned to high temperatures. The underdeveloped embryo must increase in length by >120% before the radicle emerges. Neither GA3 nor GA4 was effective in promoting radicle emergence; however, both plant growth regulators increased rate (but not percentage) of shoot emergence in root-emerged seeds. We conclude that seeds of C. wilsoniana have the deep simple level of morphophysiological dormancy (MPD), C1b-C3-B1b; thus, warm stratification followed by cold stratification and then warm-temperature incubation are required for germination. In gymnosperms, MPD is known in cycads, Ginkgo and now in three families of conifers.


HortScience ◽  
2017 ◽  
Vol 52 (8) ◽  
pp. 1122-1124 ◽  
Author(s):  
Justin A. Schulze ◽  
Jason D. Lattier ◽  
Ryan N. Contreras

A tissue culture protocol was developed to germinate immature Prunus lusitanica seeds in vitro. The study was conducted by first identifying the best media for germination, followed by investigating effects of seed conditioning. In Expt. I, seeds were collected 12 weeks after pollination (WAP) ± 1 week and placed on media after removing the pericarp. Eight different MS media (Murashige and Skoog, 1962) were tested (M1–M8) containing two concentrations each of 6-benzylaminopurine (BA), gibberellic acid (GA3), and sucrose. The longest shoots resulted from M4 (1.45 µm GA3, 6 µm BA, and 30 g·L−1 sucrose), followed by M1 (0 µm GA3, 3 µm BA, and 30 g·L−1 sucrose). Radicle and shoot emergence was greater than or equal to 90% for M1, M3, and M4 after a stratification treatment. In Expt. II, M1 was used to test root and shoot emergence at 6, 9, and 12 WAP, with and without cold stratification. Little success was seen 6 and 9 WAP, with only callus development in 6 WAP, nonstratified seed. Cold stratification increased shoot emergence in the 12 WAP group from 4% to 28%, appearing to be critical for shoot emergence. If the cotyledons are retained on the seed, future efforts to expedite breeding of P. lusitanica using in vitro germination should not be collected before 12 WAP and will benefit from cold stratification before germinating on M1 or M4. Chemical names: 6-benzylaminopurine (BA), gibberellic acid (GA3).


2018 ◽  
Vol 28 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Guadalupe Galíndez ◽  
Diana Ceccato ◽  
Rosana Bubillo ◽  
Lucía Lindow-López ◽  
Gisela Malagrina ◽  
...  

AbstractAs a contribution to understanding the world biogeography of seed dormancy in the cosmopolitan genus Ilex, we studied seeds of I. argentina, I. brasiliensis, I. brevicuspis, I. dumosa, I. paraguariensis and I. theezans from the subtropical region of Argentina. We hypothesized that seeds of these species have non-deep simple morphophysiological dormancy (MPD). Effects of temperature, cold stratification and gibberellic acid (GA3) on seed germination and embryo growth were tested. Regardless of incubation temperature, little or no germination occurred for any species until ≥6 weeks. There was an up to 3-fold increase in embryo length to seed length (E:S) ratio before seeds germinated, and embryos grew only during warm-stratifying conditions. Seeds of I. brasiliensis, I. brevicuspis and I. theezans had non-deep simple MPD and germinated to ≥80% after 12, 24 and 16 weeks, respectively. Cold stratification increased germination of I. brasiliensis and I. brevicuspis, and GA3 increased the rate but not final germination percentage of I. brasiliensis and I. theezans. Fresh seeds of I. dumosa required 40 weeks of warm stratification to germinate to 53%, while those after-ripened for 2 months germinated to 81% after 30 weeks; this species has intermediate simple MPD. Seeds of I. argentina and I. paraguariensis germinated to 15 and 21%, respectively, after 40 weeks of warm stratification and did not after-ripen or respond to GA3; these seeds have deep simple MPD. This is the first report of intermediate and deep simple MPD that is broken by warm stratification, thereby increasing our knowledge of seed dormancy in Ilex and in subtropical regions.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 85
Author(s):  
Jorge Lopez-Jimenez ◽  
Nicanor Quijano ◽  
Alain Vande Wouwer

Climate change and the efficient use of freshwater for irrigation pose a challenge for sustainable agriculture. Traditionally, the prediction of agricultural production is carried out through crop-growth models and historical records of the climatic variables. However, one of the main flaws of these models is that they do not consider the variability of the soil throughout the cultivation area. In addition, with the availability of new information sources (i.e., aerial or satellite images) and low-cost meteorological stations, it is convenient that the models incorporate prediction capabilities to enhance the representation of production scenarios. In this work, an agent-based model (ABM) that considers the soil heterogeneity and water exchanges is proposed. Soil heterogeneity is associated to the combination of individual behaviours of uniform portions of land (agents), while water fluxes are related to the topography. Each agent is characterized by an individual dynamic model, which describes the local crop growth. Moreover, this model considers positive and negative effects of water level, i.e., drought and waterlogging, on the biomass production. The development of the global ABM is oriented to the future use of control strategies and optimal irrigation policies. The model is built bottom-up starting with the definition of agents, and the Python environment Mesa is chosen for the implementation. The validation is carried out using three topographic scenarios in Colombia. Results of potential production cases are discussed, and some practical recommendations on the implementation are presented.


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