Germination and dormancy states of seeds in the environmental weed Rumex vesicarius (Polygonaceae). I. Seed polymorphism and germination of extracted seeds

2006 ◽  
Vol 54 (8) ◽  
pp. 773 ◽  
Author(s):  
Andrea Schatral ◽  
Joan M. Osborne
Keyword(s):  
Oxygen Consumption ◽  
Environmental Variables ◽  
Constant Darkness ◽  
Chemical Inhibitors ◽  
Physiological Dormancy ◽  
Seed Polymorphism ◽  
Natural Flora ◽  
Radicle Protrusion ◽  
Environmental Weed ◽  
Germination Requirements

In Australia, Rumex vesicarius (Ruby Dock; subgenus Acetosa, section Vesicarii, family Polygonaceae) is an environmental weed, with the potential to have a significant impact on the natural flora and fauna in areas where it grows. Ruby Dock seeds are polymorphic (light and dark of various shades) and of high potential viability. Seeds are enclosed within showy, papery fruiting valves at maturation. Extracted seeds are characterised by non-deep physiological dormancy. Light and dark seeds usually require an after-ripening period of several months, but thereafter germinate at any time of the year in a light–dark rhythm. Light seeds also show excellent germination in constant darkness; they are non-dormant. Dark seeds show conditional dormancy, where germination is inhibited in darkness, but not in a light–dark rhythm. Scarification experiments indicate that the conditional dormancy of dark seeds is related to the pericarp. The pericarp may restrict oxygen consumption by the embryo, contain chemical inhibitors and/or impede radicle protrusion. A range of environmental variables is likely to affect the specific germination requirements of particular seed types. Environmental conditions may induce secondary dormancy, in both light and dark seeds.

Dormancy-breaking and germination requirements for seeds of Diervilla lonicera (Caprifoliaceae), a species with underdeveloped linear embryos

2000 ◽  
Vol 78 (9) ◽  
pp. 1199-1205 ◽  
Author(s):  
Siti N Hidayati ◽  
Jerry M Baskin ◽  
Carol C Baskin
Keyword(s):  
Seed Dormancy ◽  
Constant Darkness ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Morphophysiological Dormancy ◽  
Germination Phenology ◽  
Physiological Dormancy ◽  
Temperature Controlled ◽  
Germination Requirements ◽  
Morphological Dormancy

Dormancy-breaking requirements and type of dormancy were determined for seeds of Diervilla lonicera Mill. Seeds have an underdeveloped linear embryo that is about 35% of the length of the seed at maturity. Embryos (in intact seeds) grew at 25:15°C but not at 5°C. Up to 85% of the freshly matured seeds had morphological dormancy (MD), and thus, they germinated within about 30 days on a moist substrate in light at 30:15°C; a maximum of 3% of the seeds germinated in constant darkness. The other portion of fresh seeds had nondeep simple morphophysiological dormancy (MPD) and required a period of warm stratification or treatment with GA3 to break dormancy. These seeds also required light to germinate. In contrast, cold stratification induced dormancy, and dry storage for up to 1 year did not effectively break dormancy. Seeds with MD germinated to significantly higher percentages on soil than on filter paper or on sand. Seeds sown on soil in a non-temperature-controlled greenhouse in mid-November germinated mostly in late May, whereas those sown in mid-April germinated in early May. Apparently, embryos of November-sown seeds were induced into physiological dormancy during winter. Thus, seeds had MPD in spring and needed several weeks of warm temperatures for dormancy break, embryo growth, and germination. This is the first report on seed dormancy in the genus Diervilla.Key words: embryo growth, germination phenology, Diervilla lonicera, morphological seed dormancy, morphophysiological seed dormancy, underdeveloped linear embryo.

scholarly journals Non-Deep Physiological Dormancy in Seed and Germination Requirements of Lysimachia coreana Nakai

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 490
Author(s):  
Saeng Geul Baek ◽  
Jin Hyun Im ◽  
Myeong Ja Kwak ◽  
Cho Hee Park ◽  
Mi Hyun Lee ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Germination Rate ◽  
Seed Viability ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Viability Test ◽  
Physiological Dormancy ◽  
Different Temperatures ◽  
Germination Requirements

This study aimed to determine the type of seed dormancy and to identify a suitable method of dormancy-breaking for an efficient seed viability test of Lysimachia coreana Nakai. To confirm the effect of gibberellic acid (GA3) on seed germination at different temperatures, germination tests were conducted at 5, 15, 20, 25, 20/10, and 25/15 °C (12/12 h, light/dark), using 1% agar with 100, 250, and 500 mg·L−1 GA3. Seeds were also stratified at 5 and 25/15 °C for 6 and 9 weeks, respectively, and then germinated at the same temperature. Seeds treated with GA3 demonstrated an increased germination rate (GR) at all temperatures except 5 °C. The highest GR was 82.0% at 25/15 °C and 250 mg·L−1 GA3 (4.8 times higher than the control (14.0%)). Additionally, GR increased after cold stratification, whereas seeds did not germinate after warm stratification at all temperatures. After cold stratification, the highest GR was 56.0% at 25/15 °C, which was lower than the GR observed after GA3 treatment. We hypothesized that L. coreana seeds have a non-deep physiological dormancy and concluded that 250 mg·L−1 GA3 treatment is more effective than cold stratification (9 weeks) for L. coreana seed-dormancy-breaking.

Dormancy break and germination requirements in acorns of two bottomland Quercus species (Sect. Lobatae) of the eastern United States with references to ecology and phylogeny

2020 ◽  
Vol 30 (3) ◽  
pp. 199-205
Author(s):  
Tracy S. Hawkins
Keyword(s):  
United States ◽  
Cold Stratification ◽  
Eastern United States ◽  
Closely Related Species ◽  
Temperature Regimes ◽  
Quercus Species ◽  
Physiological Dormancy ◽  
Alternating Temperature ◽  
Incubation Temperatures ◽  
Germination Requirements

AbstractQuercus species are ecologically and economically important components of deciduous forests of the eastern United States. However, knowledge pertinent to a thorough understanding of acorn germination dynamics for these species is lacking. The objectives of this research were to determine dormancy break and germination requirements for acorns of two eastern United States bottomland species, Quercus nigra and Quercus phellos (Section Lobatae), and to present results within ecological and phylogenetic contexts. Three replicates of 50 acorns of each species received 0 (control), 6, 12 or 18 weeks of cold stratification, followed by incubation in alternating temperature regimes of 15/6, 20/10, 25/15 and 30/20°C. Eighteen weeks of cold stratification were not sufficient for dormancy break in Q. nigra acorns. Cumulative germination percentages at 4 weeks of incubation were ≥77%, but only in incubation temperatures of 25/15 and 30/20°C. Dormancy break in Q. phellos acorns was achieved with 18 weeks of cold stratification, and cumulative germination percentages were ≥87% at 4 weeks of incubation in all test temperature regimes. Gibberellic acid solutions were not an effective substitute for cold stratification in either species. Phylogenetically, Q. nigra and Q. phellos are closely related species and, ecologically, both grow in the same habitat. Acorns of both species possess deep physiological dormancy (PD), but dormancy break and germination requirements differ in acorns of these two Quercus species.

A new type of non-deep physiological dormancy: evidence from three annual Asteraceae species in the cold deserts of Central Asia

2014 ◽  
Vol 24 (4) ◽  
pp. 301-314 ◽  
Author(s):  
Mihray Nur ◽  
Carol C. Baskin ◽  
Juan J. Lu ◽  
Dun Y. Tan ◽  
Jerry M. Baskin
Keyword(s):  
Central Asia ◽  
Mechanical Resistance ◽  
Dormancy Breaking ◽  
Germination Phenology ◽  
Physiological Dormancy ◽  
Temperature Requirements ◽  
Dry Conditions ◽  
New Type ◽  
Late Stages ◽  
Germination Requirements

AbstractAlthough Asteraceae species are important in the cold deserts of Central Asia, little is known about their seed dormancy and germination. We determined dormancy breaking and germination requirements of three annual Asteraceae, Echinops gmelinii, Epilasia acrolasia and Koelpinia linearis. Achenes (seeds) were tested for germination in light and in darkness over a range of alternating temperatures after various periods of burial outdoors and of dry storage. Germination phenology was monitored for seeds sown in irrigated and non-irrigated sand, and temperature requirements for dormancy break were determined under wet and dry conditions. Effects of pericarp and phyllaries on germination of E. acrolasia and E. gmelinii, respectively, were determined. Low percentages of 20-day-old seeds of E. acrolasia and K. linearis were non-dormant and germinated to low percentages over the range of temperatures, whereas all seeds of E. gmelinii were dormant. As seeds of the three species afterripened, they germinated over the range of temperatures. Whether seeds germinated in autumn or spring depended on the amount of sand moisture. Mechanical resistance of the pericarp and phyllaries reduced germination of E. acrolasia and E. gmelinii, respectively. Temperature requirements for germination as seeds come out of dormancy do not correspond to any of the known five types of non-deep physiological dormancy (PD). Thus, a sixth type is recognized in which germination occurs over the same range of temperatures in the early and late stages of dormancy break. Type 6 allows seeds to germinate at high or at low temperatures, whenever sand moisture is non-limiting.

Seed polymorphism, dormancy and germination of Salsola affinis (Chenopodiaceae), a dominant desert annual inhabiting the Junggar Basin of Xinjiang, China

2007 ◽  
Vol 55 (4) ◽  
pp. 464 ◽  
Author(s):  
Yan Wei ◽  
Ming Dong ◽  
Zhen-ying Huang
Keyword(s):  
Junggar Basin ◽  
Type A ◽  
Temporal Variations ◽  
Mother Plant ◽  
Type B ◽  
Plant Type ◽  
Physiological Dormancy ◽  
Seed Polymorphism ◽  
Type C ◽  
Desert Annual

Salsola affinis C.A. Meyer, a dominant annual that primarily occurs in deserts of the Junggar Basin, China, produces three types of utricles that differ in shape, size, colour and size of wings on the fruits. Type A fruits have lignified perianths with long wings and green utricles, and they can easily be dispersed long distances from the mother plant by wind. Type B fruits have lignified perianths with short wings, or no wings, and green utricles, and they are tightly attached to the mother plant. Type C fruits have tepals without wings and yellow utricles, and are also attached tightly to the mother plant. Freshly harvested Type A and Type B seeds (utricles) can germinate at 5–30°C in light or in darkness. Rate and final percentage of germination of Type B seeds are higher than those of Type A seeds. Type C seeds have non-deep physiological dormancy; they germinate slowly and to a low percentage. Four weeks of cold stratification, scarification of covering layers (pericarp and seed coat) and treatment with KNO3 can increase the percentage and rate of seed germination. Utricle polymorphism may allow Salsola affinis to respond to spatial and temporal variations in environmental conditions, thus increasing the chances for survival of this annual species in its harsh desert habitats.

scholarly journals Seed Germination Biology of Four Pomegranate (Punica granatum) Cultivars from Xinjiang, China

HortScience ◽  
2015 ◽  
Vol 50 (6) ◽  
pp. 826-829 ◽  
Author(s):  
Dilinuer Shalimu ◽  
Ke Li ◽  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
Yujun Liu
Keyword(s):  
Sulfuric Acid ◽  
Seed Germination ◽  
Punica Granatum ◽  
Poor Quality ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Physiological Dormancy ◽  
Pomegranate Seeds ◽  
Germination Requirements ◽  
New Cultivars

Pomegranate is an important fruit crop cultivated in many countries, and development of new cultivars depends on the plant breeders being able to produce plants from seeds. Poor quality and low yield of cultivars are widespread problems that greatly restrict development of the pomegranate industry. Our purpose was to gain a better understanding of the seed dormancy-breaking and germination requirements of four cultivars of pomegranate from Xinjiang Province, China, which would be useful in improving old cultivars and developing new ones. Fresh pomegranate seeds incubated on moist filter paper imbibed water, but they germinated to only 16% to 20%. Sulfuric acid scarification, cold stratification, and warm followed by cold stratification significantly increased germination percentages. Seeds soaked in concentrated H2SO4 for 40 minutes followed by cold stratification for 2 months germinated to 65%, and those warm stratified for 1–3 months followed by cold stratification for 2 months germinated to 75% to 80%. Seeds of pomegranate have nondeep physiological dormancy (PD).

Seed dormancy in six cold desert Brassicaceae species with indehiscent fruits

2015 ◽  
Vol 25 (3) ◽  
pp. 276-285 ◽  
Author(s):  
Juan J. Lu ◽  
Yuan M. Zhou ◽  
Dun Y. Tan ◽  
Carol C. Baskin ◽  
Jerry M. Baskin
Keyword(s):  
Seed Dormancy ◽  
Dominant Role ◽  
Extended Period ◽  
Cold Desert ◽  
North West ◽  
Chemical Inhibitors ◽  
Brassicaceae Species ◽  
Physiological Dormancy ◽  
Dispersal Unit

AbstractThe dispersal unit of many species of Brassicaceae is an indehiscent fruit, but relatively few studies have tested the effect of the pericarp on seed germination in this family. Our aim was to determine the effect of the pericarp on seed dormancy in six species of Brassicaceae native to the cold desert of north-west China. Intact dispersal units and isolated seeds of Chorispora sibirica, Euclidium syriacum, Goldbachia laevigata, Spirorrhynchus sabulosus, Sterigmostemum fuhaiense and Tauscheria lasiocarpa were stored dry at ambient laboratory conditions for 0–12 months and tested for germination in light and in dark at 5/2, 15/2 and 30/15°C. The amount of water absorbed by fruits and by seeds within the fruits was determined. For four species, intact fruits, isolated seeds and isolated seeds plus the removed pericarps were used to test for the mechanical versus possible chemical role of the pericarp in seed dormancy. Fresh isolated seeds, which have a fully developed embryo, germinated to lower percentages and rates than afterripened seeds. Thus, seeds have non-deep physiological dormancy. The pericarp significantly reduced germination, but inhibition was not due to lack of water uptake by seeds or to chemical inhibitors. Afterripened seeds of the six species germinated to 0–50% inside the fruits. We conclude that the pericarp plays a dominant role in seed dormancy of the six study species, and it does so by mechanically restricting embryo growth. Thus, the pericarp has the potential to spread germination over an extended period of time.

scholarly journals Key metabolic pathways involved in seed primary physiological dormancy maintenance of Korean pine seed

2021 ◽  
Author(s):  
Yuan Song ◽  
Xiaoye Gao
Keyword(s):  
Seed Coat ◽  
Tricarboxylic Acid Cycle ◽  
Pentose Phosphate ◽  
Metabolic Changes ◽  
Korean Pine ◽  
Metabolic Switch ◽  
Operation Rate ◽  
Physiological Dormancy ◽  
Radicle Protrusion ◽  
Stage Embryo

ABSTRACTThe metabolic changes that occurred during either cold stratification or after-ripen treatment, and in both dormant seeds and after-ripened seeds either under the dry state or during imbibition have been extensively explored. Much less is known about those present in both dormant seeds and cold stratified seeds during the same period of incubation under favorable germination conditions. Metabolite composition was investigated in both embryo and megagametophyte of primary physiological dormant seeds (PPDS) of Pinus Koreansis collected at 0 week, 1 week, 2 weeks, 4 weeks and 6 weeks of incubation, and of cold stratified seeds with released primary physiological dormancy (RPPDS) sampled at 0 week and 1 week of incubation, seed coat rupture stage and radicle protrusion stage. Embryo contained higher levels of most metabolites compared to megagametophyte. Strong metabolic changes occurred at 1 week and 4 weeks of incubation in PPDS, with most metabolites were significantly accumulated in 4-weeks-incubated PPDS. A larger metabolic switch was found in RPPDS between 1-week-incubation and seed coat rupture stage. Especially, there was a significant major decrease in the relative levels of most phosphorylated sugars and amino acids. The carbohydrate metabolism, especially pentose phosphate pathway and tricarboxylic acid cycle were more active pathways in the embryos of 4-weeks-incubated PPDS, but the operation rate of most amino acid metabolism was lower compared to 1-week-incubated RPPDS. We suggest that a larger metabolic switch in the embryo of PPDS after 4 weeks of incubation may assist in maintaining primary dormancy.One-sentence summaryA larger metabolic switch in dormant seeds after 4 weeks of incubation under favorable conditions for germination may maintain primary physiological dormancy of Korean pine seeds.

Physiological dormancy and germination requirements of seeds of several North American Rhus species (Anacardiaceae)

1999 ◽  
Vol 9 (3) ◽  
pp. 237-245 ◽  
Author(s):  
Xiaojie Li ◽  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Moisture Content ◽  
Gibberellic Acid ◽  
Incubation Period ◽  
North American ◽  
Close Relative ◽  
Initial Weight ◽  
Temperature Range ◽  
Physiological Dormancy ◽  
Germination Requirements

AbstractFourteen seedlots of five species of Rhus were surveyed for presence/absence of physiological dormancy and/or for germination requirements of non-dormant seeds. Physiological dormancy was present in the four seedlots of R. aromatica studied, but not in either of the two seedlots of its close relative R. trilobata, which is in contrast to previous reports. Neither were seeds of R. glabra, R. typhina, nor R. virens physiologically dormant. Stratification at 5oC for 1 week or incubation in 500 or 1000 mg/l solutions of gibberellic acid broke physiological dormancy in > 90% of the R. aromaticaseeds. Maturation desiccation acted as a switch from a developmental to a germinative mode in R. aromatica embryos, whereas it was not required for germination of R. glabra or R. virens (R. trilobata and R. typhinanot tested). Seeds of all five species incubated on a moist substrate became fully imbibed in 2 d, at which time moisture content was approx. 70–80%of their initial weight. In general, germination of non-dormant seeds was rather insensitive to temperature and light. Seeds germinated equally well in light and in darkness over a daily (12 h/12 h) temperature range of 15/6–35/20oC. Over a 4 week period, the best germination percentages were obtained at 25/15 and 20/10oC, whereas 35/20oC appeared to be supraoptimal, though not always significantly so. If the incubation period was extended to 30 weeks, germination percentages were as high at 15/6oC as at 25/15 and 20/10oC.

Nitrate controls testa rupture and water content during release of physiological dormancy in seeds of Sisymbrium officinale (L.) Scop.

2015 ◽  
Vol 25 (2) ◽  
pp. 138-146 ◽  
Author(s):  
Peter E. Toorop
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Water Content ◽  
Sensu Stricto ◽  
Second Phase ◽  
Dormancy Release ◽  
Synthesis Inhibitor ◽  
Seed Analysis ◽  
Physiological Dormancy ◽  
Radicle Protrusion

AbstractSeeds of Sisymbrium officinale display physiological dormancy and require nitrate to germinate. Rupture of the testa precedes radicle protrusion through the endosperm (germination sensu stricto). While both endosperm rupture and testa rupture (TR) required nitrate, endosperm rupture was fully inhibited by abscisic acid (ABA) but TR was not inhibited. The gibberellic acid (GA)-synthesis inhibitor paclobutrazol prevented TR, which was reverted by exogenous GA4 but not by nitrate. The orientation of TR was transverse, which prompted the question whether seeds elongate prior to radicle protrusion, concurrent with an increase in water content. Between 9 h and 1 d no increase in length or water content was observed. During incubation in ABA the length of imbibed seeds without TR did not increase between 1 and 5 d, whereas nitrate added to ABA induced TR and a 94% increase in length. At the same time the water content of seeds without TR increased by 18%, while the water content of seeds with TR increased by 38%. Length and water content were correlated in a single-seed analysis for seeds with TR, but not for seeds without TR. Increased length was also observed in Arabidopsis seeds with nitrate-induced TR. These results indicate that prior to endosperm rupture dormancy release by nitrate is accompanied by TR, seed elongation and an increase in water content. A new multiphasic model is proposed for the imbibition curve, where the second phase of the classical triphasic curve is split into three sub-phases, of which phases IIB and IIC are associated with TR.

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