Deep complex morphophysiological dormancy in seeds of Viburnum plicatum var. formosanum (Adoxaceae) from subtropical mountains

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.

Author(s):  
Chunyu Shao ◽  
Guanying Wang ◽  
Xin Ding ◽  
Chao Yang ◽  
Min Yan

Cold stratification is commonly used for breaking morphophysiological dormancy in Glehnia littoralis seeds. However, the physiological and biochemical characteristics of dormancy release are still unclear. For our study, dormant G. littoralis seeds were subjected to cold stratification (4°C). Physiological and biochemical characteristics, including germination percentage, the activities of antioxidant enzymes and α-amylase, and soluble sugar, soluble protein, H2O2, malondialdehyde (MDA) and coumarin were determined in imbibed seeds after different stratification periods (0, 30, 60, 90 or 120 days). The morphophysiological dormancy in G. littoralis seeds was completely released by cold stratification for 120 days. The activities of catalase (CAT) and content of hydrogen peroxide (H2O2) and total soluble sugars were significantly increased, while coumarins was significantly decreased during dormancy release. Dormancy release was significantly positively correlated with CAT activity (r = 0.903) and accumulation of H2O2 (r = 0.985) and total soluble sugars (r = 0.952), and significantly negatively correlated with coumarins (r = −0.919). Thus, the increase in H2O2, soluble sugars level and CAT activity and decrease in coumarins during cold stratification might contribute to promoting dormancy release in G. littoralis seeds.


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).


2018 ◽  
Vol 28 (1) ◽  
pp. 52-62 ◽  
Author(s):  
Majid Fasih ◽  
Reza Tavakkol Afshari

AbstractFerula ovina is a perennial Apiaceae with great medicinal and economic value. This study was conducted to better understand the dormancy and germination behaviour of its seeds. Experiments included temperature requirements for both embryo growth and germination under field and laboratory conditions, the effects of warm stratification, gibberellic acid (GA3), dry after-ripening, exogenous hydrogen peroxide (H2O2) and diphenyleneiodonium (DPI) on dormancy, localizing the accumulation of superoxide (O2−) and measuring endogenous contents of H2O2 in embryos during cold and warm stratification. Embryos were under-developed and did not germinate within one month at temperatures higher than 10°C. Among all treatments, cold stratification and exogenous H2O2 could break dormancy. However, the application of DPI reduced growth and the germination of the embryo at 3°C. During cold stratification, the embryonic axes elongated more than the cotyledons, which coincided with earlier production of O2− in the axes. Only these embryos could eventually complete growth and germinate. Moreover, such asymmetric growth between the axes and cotyledons was also observed when seeds were treated with exogenous H2O2. On the other hand, both axes and cotyledons displayed the same growth over treatments with warm stratification and DPI. Overall, seeds of F. ovina exhibit the characteristics of deep complex morphophysiological dormancy. Moreover, the embryos solely require cold to complete growth and to germinate, and this process seems to be mediated by reactive oxygen species. Under natural conditions, seeds germinate during winter in cold soil, and shoots emerge in spring.


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.


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).


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.


2011 ◽  
Vol 21 (4) ◽  
pp. 267-281 ◽  
Author(s):  
Elena Copete ◽  
José M. Herranz ◽  
Miguel A. Copete ◽  
Jerry M. Baskin ◽  
Carol C. Baskin

AbstractHeretofore, no detailed account was available on seed dormancy and germination of a member of the Colchicaceae (Liliales). Thus, the primary aim of this study was to do an in-depth investigation of the temperature requirements for dormancy break and germination in seeds ofMerendera montana(Colchicaceae) at the embryo and whole-seed levels under near-natural temperatures in a non-heated frame shade-house and under controlled conditions in the laboratory. Mean embryo length in fresh seeds wasc. 0.57 mm and embryos had to grow to at least 1.30 mm before radicle emergence. Embryos grew to full size and seeds completed germination (radicles emerged) when they were stratified at 28/14°C for 60 d followed by a cool temperature for 60 d and then incubated at a cool temperature for 30 d. The optimum cool stratification temperature for dormancy-break was 10°C. Thus, after the moist pretreatment at 28/14°C+10°C, radicle emergence was>93% at all incubation temperatures (5, 15/4 and 20/7°C). In its natural habitat,M. montanaseeds are dispersed in June, the embryo elongates to full size in autumn and radicles emerge from early November to early February. Although the shoot does not emerge until March and April, it is not physiologically dormant. The shoot emerged from 80% of the radicle-emerged seeds in 13 d at 20/7°C without a previous cold pretreatment. Seeds ofM. montanahave non-deep complex morphophysiological dormancy, C1b1aB-C1a. This is the first study on seeds with complex MPD to show a delay in shoot emergence following root emergence despite the shoot being physiologically non-dormant.


EDIS ◽  
2018 ◽  
Vol 2018 (5) ◽  
Author(s):  
Jose C.B. Dubeux ◽  
Nicolas DiLorenzo ◽  
Kalyn Waters ◽  
Jane C. Griffin

Florida has 915,000 beef cows and 125,000 replacement heifers (USDA, 2016). Developing these heifers so that they can become productive females in the cow herd is a tremendous investment in a cow/calf operation, an investment that takes several years to make a return. The good news is that there are options to develop heifers on forage-based programs with the possibility of reducing costs while simultaneously meeting performance targets required by the beef industry. Mild winters in Florida allows utilization of cool-season forages that can significantly enhance the performance of grazing heifers. During the warm-season, integration of forage legumes into grazing systems will provide additional nutrients to meet the performance required to develop a replacement heifer to become pregnant and enter the mature cow herd. In this document, we will propose a model for replacement heifer development, based on forage research performed in trials at the NFREC Marianna.   


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 264
Author(s):  
Kathryn E. Ritz ◽  
Bradley J. Heins ◽  
Roger D. Moon ◽  
Craig C. Sheaffer ◽  
Sharon L. Weyers

Organic dairy cows were used to evaluate the effect of two organic pasture production systems (temperate grass species and warm-season annual grasses and cool-season annuals compared with temperate grasses only) across two grazing seasons (May to October of 2014 and 2015) on milk production, milk components (fat, protein, milk urea nitrogen (MUN), somatic cell score (SCS)), body weight, body condition score (BCS), and activity and rumination (min/day). Cows were assigned to two pasture systems across the grazing season at an organic research dairy in Morris, Minnesota. Pasture System 1 was cool-season perennials (CSP) and Pasture System 2 was a combination of System 1 and warm-season grasses and cool-season annuals. System 1 and System 2 cows had similar milk production (14.7 and 14.8 kg d−1), fat percentage (3.92% vs. 3.80%), protein percentage (3.21% vs. 3.17%), MUN (12.5 and 11.5 mg dL−1), and SCS (4.05 and 4.07), respectively. Cows in System 1 had greater daily rumination (530 min/day) compared to cows in System 2 (470 min/day). In summary, warm-season annual grasses may be incorporated into grazing systems for pastured dairy cattle.


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