scholarly journals Dormancy Breaking Treatments in Northern Wild Rice (Zizania palustris L.) Seed Suggest a Physiological Source of Dormancy

2021 ◽  
Author(s):  
Lillian McGilp ◽  
Aaron Semington ◽  
Jennifer Kimball

AbstractDormancy is a limiting factor for breeding in northern wild rice (NWR; Zizania palustris L). This study developed a dormancy curve and tested a combination of scarification and hormone treatments, across three timepoints, for their ability to break dormancy in NWR and produce viable seedlings and plants. A dormancy curve was established across 9 months post-harvest, which showed maximum germination (95%) by 17 weeks post-harvest and high germination (≥81 %) through the rest of the testing period. Next, dormancy breaking treatments were tested. At 1 week post-harvest, few seeds germinated (≤ 15 %) across all treatment combinations. However, sulfuric acid increased germination shortly after harvest (5.8 %), compared to water (0.5 %) and NaClO (0 %) but resulted in stunted seedlings, all but one of which died shortly thereafter. At 7 weeks, sulfuric acid treated seeds did not result in significantly higher germination than water and maximum germination was still below 15%. By 11 weeks post-harvest, the water treatments had the highest germination and resulted in the most viable plants, indicating that dormancy had begun to break naturally and exceeded the effect of the other scarification treatments. Hormonal treatments had no significant effect on germination or seed viability and no strong conclusions could be drawn about their effect on seedling or plant health. Due to the inability of early germinated seed to consistently produce viable plants and the increase in germination following sufficient cold storage, it is likely that NWR seed has intermediate or deep physiological 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.


HortScience ◽  
2015 ◽  
Vol 50 (6) ◽  
pp. 826-829 ◽  
Author(s):  
Dilinuer Shalimu ◽  
Ke Li ◽  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
Yujun Liu

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).


2009 ◽  
Vol 57 (2) ◽  
pp. 139 ◽  
Author(s):  
Geoffrey E. Burrows ◽  
James M. Virgona ◽  
Roger D. Heady

Acacia melanoxylon (Mimosoideae or Mimosaceae) is a high quality timber tree with an extensive natural distribution in Australia and a wide genetic and phenotypic diversity. Seeds from three widely differing provenances in Tasmania were tested to determine whether they had different responses to various dormancy-breaking treatments. All provenances had limited germination (<11%) if seeds were untreated and between 85% and 91% germination after 40 days if the seeds were nicked. For all provenances short (≤60 s) exposure to boiling water gave high germination percentages. These values were generally lower, although usually not significantly so, than the germination percentages following nicking. Germination percentages decreased with increasing time of exposure to boiling water, although one provenance had a significantly greater tolerance to one of the longer (20 min) treatments. Nicked seeds germinated quickly and uniformly, whereas those subjected to the boiling-water treatments germinated after a longer period and more gradually. In untreated seeds, the lens was a low, elliptically shaped dome (~110–135 µm wide, 140–190 µm long). In more than 99% of the seeds examined, the structure of the lens was markedly altered after a 10-s exposure to boiling water. A wide diversity of altered lens structure was found, from a circular hole between the macrosclereids, to a short fissure where the macrosclereids did not separate to their bases. Nicked seeds had a 200–375 times greater area for water uptake than a fully disrupted lens and this was probably the principal reason why the nicked seeds germinated sooner and more rapidly.


2020 ◽  
Vol 30 (1) ◽  
pp. 21-28
Author(s):  
Lillian McGilp ◽  
Jacques Duquette ◽  
Daniel Braaten ◽  
Jennifer Kimball ◽  
Raymond Porter

AbstractCultivated northern wild rice (NWR; Zizania palustris L.) has been bred and studied since the 1950s. One challenge facing researchers is the lack of storage options, due to the seed's unorthodox behaviour. This study evaluated varying storage temperature and moisture conditions for the maintenance of seed viability and dormancy breaking in Minnesota-grown NWR. First, seeds were placed in non-submerged, freezing storage (NSFS) for 12–26 weeks, then in submerged, cold storage (SCS) for 2 weeks. The addition of SCS increased germination (%G) relative to NSFS alone (<0.1% NSFS, 15% NSFS and SCS), indicating that NSFS does not kill seeds but also does not break seed dormancy. Next, the required length of SCS was evaluated by placing seeds in NSFS for 12 weeks and then in SCS for 2–14 weeks. A longer SCS period increased %G from 3 to 79%, at 2 and 14 weeks of SCS, respectively. Lastly, seeds were placed in NSFS, followed by SCS, at varying intervals over a 29-week period. Across lines, germination increased from 20 to 76% between 4 and 7 weeks of SCS, respectively, then plateaued. The results of this study indicate that NSFS could be used to store NWR seeds, but at least 7 weeks in SCS is required to overcome dormancy. Additionally, while NSFS did not break seed dormancy, physiological changes related to stratification processes were occurring in non-submerged, freezing conditions. Results also suggest that the genotypic variation in NWR could be utilized for selection to improve germination and storage viability.


1993 ◽  
Vol 89 (1) ◽  
pp. 165-171 ◽  
Author(s):  
Douglas G. Muench ◽  
O. William Archibold ◽  
Allen G. Good

Horticulturae ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 86
Author(s):  
Abdel-Moety Salama ◽  
Ahmed Ezzat ◽  
Hassan El-Ramady ◽  
Shamel M. Alam-Eldein ◽  
Sameh Okba ◽  
...  

Adequate chill is of great importance for successful production of deciduous fruit trees. However, temperate fruit trees grown under tropical and subtropical regions may face insufficient winter chill, which has a crucial role in dormancy and productivity. The objective of this review is to discuss the challenges for dormancy and chilling requirements of temperate fruit trees, especially in warm winter regions, under climate change conditions. After defining climate change and dormancy, the effects of climate change on various parameters of temperate fruit trees are described. Then, dormancy breaking chemicals and organic compounds, as well as some aspects of the mechanism of dormancy breaking, are demonstrated. After this, the relationships between dormancy and chilling requirements are delineated and challenging aspects of chilling requirements in climate change conditions and in warm winter environments are demonstrated. Experts have sought to develop models for estimating chilling requirements and dormancy breaking in order to improve the adaption of temperate fruit trees under tropical and subtropical environments. Some of these models and their uses are described in the final section of this review. In conclusion, global warming has led to chill deficit during winter, which may become a limiting factor in the near future for the growth of temperate fruit trees in the tropics and subtropics. With the increasing rate of climate change, improvements in some managing tools (e.g., discovering new, more effective dormancy breaking organic compounds; breeding new, climate-smart cultivars in order to solve problems associated with dormancy and chilling requirements; and improving dormancy and chilling forecasting models) have the potential to solve the challenges of dormancy and chilling requirements for temperate fruit tree production in warm winter fruit tree growing regions.


2013 ◽  
Vol 230 (2) ◽  
pp. 284-292 ◽  
Author(s):  
Gangadaran Surendiran ◽  
ChunYan Goh ◽  
Khuong Le ◽  
Zhaohui Zhao ◽  
Fatemeh Askarian ◽  
...  

2017 ◽  
Vol 36 (8) ◽  
pp. 2217-2226 ◽  
Author(s):  
Douglas J. Fort ◽  
Kevin Todhunter ◽  
Troy D. Fort ◽  
Michael B. Mathis ◽  
Rachel Walker ◽  
...  

2022 ◽  
Vol 354 (11-12) ◽  
pp. 97-99
Author(s):  
M. A. Starostina ◽  
N. G. Lapenko

Relevance. Biological features (morphometric indicators, viability and germinating power) of Poterium polygamum seeds found in natural communites of the Stavropol Territory have been studied. The conservation of wild-growing plant species in the natural population and the rational use of their potential are relevant.Methods. Years of study — 2013–2021. The subject of the study is Poterium polygamum seeds. Seeds were collected in 2013. Studies were carried out according to the methods of studying seed material. Freshly harvested seeds and seeds of different shelf life were germinated in petri dishes at a temperature of 18–20 °C.Results. The collected seeds of Poterium polygamum are quite large. The length of the seeds is 4–5 mm, the width is about 2.5 mm. The mass of 1000 pieces of seeds on average was 10.59 grams. Complete absence of viability of freshly harvested Poterium polygamum seeds was revealed. After three months, seed viability was 97%. This is a shallow physiological rest associated with the post-harvest maturation period. During the storage of seeds, their high germination was established — from 70 to 100%. The duration of seed storage is 8 years. The largest number of germinated seeds and their germinating power were noted in the third year of their storage (100%). Seeds germinated on the third or fourth day. The differences between the viability of seeds and their germinating power are not great. In the eighth year of storage of Poterium polygamum seeds, viability and germinating power were slightly reduced. The storage period of seeds, in which they retain the ability to germinate and the germinating power, is long. It has been found that the wild species Poterium polygamum belongs to plants with a high (70 to 100%) viability. This species is regularly resumed in the natural population. The revealed biological features of Poterium polygamum seeds can become the scientific basis during the reconstruction of degraded natural grass stand and in selection work.


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