scholarly journals Non-deep physiological dormancy in seeds of Euphorbia jolkinii Boiss. native to Korea

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Hye Jin Oh ◽  
Un Seop Shin ◽  
Seung Youn Lee ◽  
Sang Yong Kim ◽  
Mi Jin Jeong

Abstract Background Euphorbia jolkinii Boiss. is a perennial species native to Jeju Island and the southern coastal area of Korea. Particularly on Jeju Island, the yellow flowers of E. jolkinii Boiss. have a high ornamental value because of their contrast with basalt. This study was conducted to investigate the effects of different temperatures (5, 15, 20, and 25 °C) and gibberellic acid (GA3) concentrations (0, 10, 100, or 1000 mg/L) on seed dormancy and germination of E. jolkinii. In addition, we classified the seed dormancy type and compared types with those of other species in the same genus. Results The number of seeds with viable embryos and endosperms was approximately 66%. The final germination percentages at 5, 15, 20, and 25 °C were 51.7%, 83.5%, 2.6%, and 0.0%, respectively. In GA3 concentration experiments, the final germination percentages of 0, 10, 100, and 1000 mg/L were 83.5%, 91.7%, 79.1%, and 83.4%, respectively, at 15 °C conditions, and 0.0%, 6.9%, 13.2%, and 27.3%, respectively, at 25 °C. Conclusions Germination improved at temperatures of 15 °C or lower. Furthermore, GA3 treatment effectively reduced germination times. Thus, the seeds of E. jolkinni were classified as having non-deep physiological dormancy.

2005 ◽  
Vol 15 (4) ◽  
pp. 349-356 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
Alvin Yoshinaga ◽  
Ken Thompson

This study addressed the difficulty of germinating drupelets (hereafter seeds) in the multi-seeded stony dispersal units (drupes) of Leptecophylla tameiameiae (Ericaceae). Embryos in fresh seeds were 77% the length of the endosperm, and seeds inside the intact drupes imbibed water. We monitored germination at 15/6, 20/10 and 25/15°C for 162 weeks, after which each drupe was cut open and ungerminated seeds counted. Drupes contained 1–6 seeds, and the total number of seeds in all treatments and controls was 1977, with 20, 29, 25, 18, 7 and <1% of them occurring in one-, two-, three-, four-, five- and six-seeded drupes, respectively. The percentage of seeds germinating in one-, two-, three-, four-, five- and six-seeded drupes was 74, 66, 65, 72, 56 and 0, respectively. Neither warm nor cold stratification for 6 or 12 weeks significantly increased germination percentages, compared to controls incubated continuously at 25/15°C for 162 weeks, where 72% of the seeds in the drupes germinated. At 25/15°C, 24–49 weeks were required for 20% of the seeds to germinate. Warm followed by cold stratification did not promote germination, and there was no widening of the temperature range for germination. Like seeds of other species known to have deep physiological dormancy (PD), those of L. tameiameiae required extended periods of time (16 to ≥162 weeks) to come out of dormancy and germinate, gibberellic acid (GA3) did not promote germination and excised embryos failed to grow. Thus, we conclude that seeds of L. tameiameiae have deep PD. However, unlike seeds of other species with deep PD, those of L. tameiameiae required an extensive period of warm rather than of cold stratification to come out of dormancy. It is suggested that a subtype a (seeds require a long period of cold stratification to come out of dormancy) and a subtype b (seeds require a long period of exposure to warm stratification to come out of dormancy) of deep PD be recognized in the Nikolaeva formula system for classifying seed dormancy.


Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 490
Author(s):  
Saeng Geul Baek ◽  
Jin Hyun Im ◽  
Myeong Ja Kwak ◽  
Cho Hee Park ◽  
Mi Hyun Lee ◽  
...  

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.


1979 ◽  
Vol 57 (16) ◽  
pp. 1729-1734 ◽  
Author(s):  
A. I. Hsiao

The seed coverings, including the pericarp and testa of the caryopsis and the hull, arc the main barriers to the exchange of gases and the penetration of exogenous gibberellic acid (GA3) for germination of wild oats (Avena fatua L.). Dormancy was induced in seeds by immersing them in water for 15 minor longer. Dormancy induction was greater in those seeds immersed for up to 1 h in 6% sodium hypochlorite (NaOCl) and then 1 h in water than in those seeds immersed only in water for 1 h. The addition of GA3, to seeds subjected to NaOCl treatment for 15 min or less did not break dormancy, indicating a slow rate of entry, or the exclusion, of GA3, by the seeds. In the presence of GA3, germination increased with increasing exposure to NaOCl. Maximum germination was obtained by immersing dry seeds in NaOCl for 2 h, in water for 1 h, and then incubating the seeds in GA3. Gibberellic acid was not required for complete germination of imbibed, dehulled seeds immersed in NaOCl for 1 h then in water for 1 h, but it was necessary to use 10−4 M GA3 for complete germination of intact seeds that were treated with NaOCl or 2 h then with water for 1 h. Imbibed, dormant seeds that were dehulled and pierced required 10−7 M GA3, to give complete germination in this study. Piercing of the seed coverings enhances GA3, penetration and thus increases the availability of GA3, for germination. NaOCl treatment to the seeds mimics the effects of piercing. NaOCl may also have caused loss of germination inhibitors or rendered these inhibitors susceptible to oxidation. However, prolonged NaOCl treatment resulted in either poor germination or seed disintegration.


Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 160
Author(s):  
Gyeong Ho Jang ◽  
Jae Min Chung ◽  
Yong Ha Rhie ◽  
Seung Youn Lee

Veronicastrum sibiricum is a perennial species distributed in Korea, Japan, Manchuria, China, and Siberia. This study aimed to determine the requirements for germination and dormancy break of V. sibiricum seeds and to classify the kind of seed dormancy. Additionally, its class of dormancy was compared with other Veronicastrum and Veronica species. V. sibiricum seeds were permeable to water and had a mature embryo during seed dispersal. In field conditions, germination was prevented by physiological dormancy, which was, however, relieved by March of the next year, allowing the start of germination when suitable environmental conditions occurred. In laboratory experiments, the seeds treated with 0, 2, 4, 8, and 12 weeks of cold stratification (4 °C) germinated to 0, 79, 75, 72, and 66%, respectively. After the GA3 treatment (2.887 mM), ≥90% of the seeds germinated during the four incubation weeks at 20/10 °C. Thus, 2.887 mM GA3 and at least two weeks at 4 °C were effective in breaking physiological dormancy and initiating germination. Therefore, the V. sibiricum seeds showed non-deep physiological dormancy (PD). Previous research, which determined seed dormancy classes, revealed that Veronica taxa have PD, morphological (MD), or morphophysiological seed dormancy (MPD). The differences in the seed dormancy classes in the Veronicastrum-Veronica clade suggested that seed dormancy traits had diverged. The results provide important data for the evolutionary ecological studies of seed dormancy and seed-based mass propagation of V. sibiricum.


1999 ◽  
Vol 77 (4) ◽  
pp. 488-493 ◽  
Author(s):  
Carol C Baskin ◽  
Jerry M Baskin ◽  
Edward W Chester

Ninety-seven percent of the Rhexia mariana L. seeds collected in Tennessee were physiologically dormant at maturity in autumn, and they became nondormant during stratification. Light was required for germination, and seeds germinated to higher percentages on filter paper than on sand. Seeds buried in soil in October 1992 and 1994 and exposed to natural seasonal temperatures were exhumed and tested for germination at monthly or bimonthly intervals for 30 and 32 months, respectively. Seeds gained the ability to germinate to 80% or more at 30:15 and 35:20°C during the first winter of burial and also at 25:15°C during the second winter, but they did not re-enter dormancy. In contrast, seeds incubated at 20:10°C exhibited an annual cycle of moderate to high germination percentages in winter-spring and low germination percentages in summer-autumn. Thus, germination can occur at habitat temperatures in Tennessee from April to September. This is the first report of physiological dormancy in seeds of the Melastomataceae in the temperate region. Like members of many plant families in temperate eastern North America, seeds of R. mariana (i) show a decrease in the minimum temperature for germination as they come out of dormancy and (ii) exhibit some seasonal variation in the temperature range for germination. Thus, these dormancy or germination characteristics appear to be adaptations of species to the climatic conditions in temperate eastern North America.Key words: seed dormancy, seed germination, dormancy cycles, buried seeds, Melastomataceae, Rhexia.


2009 ◽  
Vol 19 (4) ◽  
pp. 261-266 ◽  
Author(s):  
S.R. Turner ◽  
K.W. Dixon

AbstractSeeds of the iconic Australian baobab Adansonia gregorii display physical dormancy (PY) and germinate readily once they become water permeable, a trait found in most other species in this genus. Highest germination (100%) was observed when seeds were placed in concentrated sulphuric acid (H2SO4) for 24 h, although exposure to H2SO4 for 6–12 h also resulted in >85% germination. Exposure to boiling water for 1–5 min was far less effective in promoting germination (0–23%), although a high number of seeds were water permeable (67–99%) following boiling water treatment. However, the majority of these water-permeable seeds appeared to have been injured by boiling water exposure. Germination at warmer temperatures (30 or 35°C) was found to be optimal (81–83% germination) and proceeded rapidly, with maximum germination occurring after incubation for only 8 d. In comparison, germination at 15–25°C resulted in 3–67% germination over a longer time frame (up to 20 d). While seeds of A. gregorii display PY they are unusually sensitive to dipping in boiling water and are therefore atypical when compared to most other Adansonia species.


Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 937
Author(s):  
Yingzeng Yang ◽  
Chuan Zheng ◽  
Umashankar Chandrasekaran ◽  
Liang Yu ◽  
Chunyan Liu ◽  
...  

Seed germination is one of the most important stages during plant life cycle, and DOG1 (Delay of germination1) plays a pivotal regulatory role in seed dormancy and germination. In this study, we have identified the DOG1-Like (DOG1L) family in soybean (Glycine max), a staple oil crop worldwide, and investigated their chromosomal distribution, structure and expression patterns. The results showed that the GmDOG1L family is composed of 40 members, which can be divided into six subgroups, according to their evolutionary relationship with other known DOG1-Like genes. These GmDOG1Ls are distributed on 18 of 20 chromosomes in the soybean genome and the number of exons for all the 40 GmDOG1Ls varied greatly. Members of the different subgroups possess a similar motif structure composition. qRT-PCR assay showed that the expression patterns of different GmDOG1Ls were significantly altered in various tissues, and some GmDOG1Ls expressed primarily in soybean seeds. Gibberellic acid (GA) remarkably inhibited the expression of most of GmDOG1Ls, whereas Abscisic acid (ABA) inhibited some of the GmDOG1Ls expression while promoting others. It is speculated that some GmDOG1Ls regulate seed dormancy and germination by directly or indirectly relating to ABA and GA pathways, with complex interaction networks. This study provides an important theoretical basis for further investigation about the regulatory roles of GmDOG1L family on soybean seed germination.


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