共查询到20条相似文献,搜索用时 15 毫秒
1.
Sanaz Zardari Farshid Ghaderi-Far Hamid R. Sadeghipour Ebrahim Zeinali Elias Soltani Carol C. Baskin 《Plant Species Biology》2019,34(3):85-94
We tested the hypothesis that seeds of the monocarpic perennial Ferula gummosa from the Mediterranean area and central Asia have deep complex morphophysiological dormancy. We determined the water permeability of seeds, embryo morphology, temperature requirements for embryo growth and seed germination and responses of seeds to warm and cold stratification and to different concentrations of GA3. The embryo has differentiated organs, but it is small (underdeveloped) and must grow inside the seed, reaching a critical embryo length, seed length ratio of 0.65–0.7, before the seed can germinate. Seeds required 9 weeks of cold stratification at <10°C for embryo growth, dormancy break and germination to occur. Thus, seeds have morphophysiological dormancy (MPD). Furthermore, GA3 improved the germination percentage and rate at 5°C and promoted 20 and 5% germination of seeds incubated at 15 and 20°C, respectively. Thus, about 20% of the seeds had intermediate complex MPD. For the other seeds in the seed lot, cold stratification (5°C) was the only requirement for dormancy break and germination and GA3 could not substitute for cold stratification. Thus, about 80% of the seeds had deep complex MPD. 相似文献
2.
Desert annual Suaeda acuminata produces two morphologically distinct types of seeds on the same plant. The main aims of our study were to compare germination characteristics of the dimorphic seeds, ascertain their dormancy types and give the hormonal explanation. The two seed types of S. acuminata absorbed water at different rates with brown seeds imbibing water faster. Germination percentages of brown seeds were significantly higher than those of black seeds in all temperature and light regimes tested. Eight weeks of cold stratification did not break dormancy of black seeds, whereas exogenous GA3 promoted germination. Excised embryos of untreated black seeds produced normal seedlings. Contents of ZR, GA3 and ABA of brown seeds were significantly higher than that of black seeds; while contents of IAA of black seeds were significantly higher than that of brown seeds. Brown seeds of S. acuminata are non-dormant, whereas black seeds have intermediate physiological dormancy (PD). Interaction among ZR, ABA and GA3 may play an important role in dormancy status of both seed types. This is the first report of non-dormancy and intermediate PD in a heteromorphic species. 相似文献
3.
Nicoletta Rascio Paola Mariani Francesca Dalla Vecchia Nicoletta La Rocca Paola Profumo Paola Gastaldo 《Plant Growth Regulation》1998,25(1):53-61
Germination and post-germination events have been compared in seeds of Cercis siliquastrum whose dormancy was removed by fulfilling the natural chilling requirement or by exogenous GA3 application.Compared to the chilled ones, the GA3 treated seeds showed precocious embryo growth and an earlier reserve mobilization, which started before radicle emergence.Although the hormonal application was interrupted at seed germination, the plantlets of Cercis siliquastrum that originated from GA3-supplied seeds were taller than those from chilled ones. Moreover, they produced a greater number of leaves but a reduced root mass and had some difficulty in maintaining a good water balance.Thus, the treatment of Cercis siliquastrum seeds with exogenous GA3 broke dormancy and induced germination, but also caused long-lasting consequences on morphogenesis of the growing plantlet. 相似文献
4.
Yong Wook Kim So Young Park In Sun Park Heung Kyu Moon 《Plant biotechnology reports》2007,1(4):237-242
We have tested plantlet formation by somatic embryogenesis using immature seeds of Magnolia obovata. Seed collection date appeared to be critical for embryogenic cell induction. The optimal collection date was 3–4 weeks postanthesis.
The embryogenic cells proliferated, formed somatic embryos, and were subsequently converted into normal plantlets under optimized
culture conditions. Somatic embryo formation from the embryogenic calli was better on sucrose medium than on glucose medium.
The optimum level of sucrose appeared to be 3% with an average of 28 somatic embryos per plate. About 25% of somatic embryos
were converted into normal plantlets in 1/2 MS medium containing gibberellic acid (GA3). During somatic embryo germination, secondary embryogenesis was frequently observed in the lower part of the hypocotyl or
radicle ends of germinating somatic embryos. Finally, about 85% of converted plantlets survived in an artificial soil mixture,
were transferred to a nursery, and have grown normally. 相似文献
5.
《农业工程》2023,43(1):54-61
The population of Magnolia lanuginosa a rare tree species of northeastern India has declined drastically owing to habitat destruction, low natural regeneration and over harvesting for its multipurpose uses. The present study was carried out to understand the type of dormancy and analyse the effect of storage on viability and germination behaviour of M. lanuginosa under various physical and chemical treatments. Seeds subjected to physical treatments such as water (cold, hot, and boiling), acid (H2SO4) and manual scarification failed in breaking dormancy. Seeds treated with growth regulators (GA3) had a significant effect on germination. It reduced the germination time and the shortest T50 was observed in seeds treated with 2000 mg/l of GA3 (non-scarified seeds) and 1000 mg/l of GA3 (scarified seeds). The use of KNO3 did not have any significant effect in breaking dormancy. However, the use of KNO3 along with GA3, increased the germination percentage. Seeds cold stratified (CS) for 60 days at 5 °C was effective in breaking dormancy and resulted in 84.26% germination. This indicates the prevalence of Type-1 Non deep physiological dormancy in M. lanuginosa seeds that requires a crucial CS period for proper embryo growth and development. The seeds stored in moist sand at 5 °C remained viable even after 120 days with 48.88% viability. The study would be helpful in devising seed germination protocols for mass production and reintroduction of the species into the wild. 相似文献
6.
Abstract Water stress effects on germinating seeds of Haplopappus gracilis (Nutt.) Gray pretreated with gibberellin and fusicoccin.—Achenes of Haplopappus gracilis, deprived of their coats, were germinated for various times, dried and then rehydrated. After this procedure many seeds were not able to resume regular germination and to overcome the water stress. After having examined the morphological changes consequent to the water stress treatments we have checked if, as suggested by some Authors, there was a correlation between the resumption of DNA synthesis in the apical meristems of the rootlets and irreversible drought sensitivity. To this purpose, embryos were pre-imbibed in water and in solutions of gibberellin (GA3), which in Haplopappus promotes resumption of DNA synthesis, and fusicoccin (FC) which strongly stimulates germination and embryo elongation, without altering the pattern of DNA synthesis. Our data show that embryos pre-imbibed in water or GA3 and then dried, do not show any difference in their ability to resume germination, while embryos pre-hydrated in FC are always damaged more precociously and more severely by the dehydration treatments. These results suggest that, since fusicoccin promotes embryo elongation through an activation of cell membranes, the physiological condition of these may be more critical for resumption of growth after the water stress than DNA replication activity. 相似文献
7.
E. M. Bicalho M. Pintó‐Marijuan M. Morales M. Müller S. Munné‐Bosch Q. S. Garcia 《Plant biology (Stuttgart, Germany)》2015,17(5):990-996
The hormonal mechanisms involved in palm seed germination are not fully understood. To better understand how germination is regulated in Arecaceae, we used macaw palm (Acrocomia aculeata (Jacq.) Lodd. Ex Mart.) seed as a model. Endogenous hormone concentrations, tocopherol and tocotrienol and lipid peroxidation during germination were studied separately in the embryo and endosperm. Evaluations were performed in dry (D), imbibed (I), germinated (G) and non‐germinated (NG) seeds treated (+GA3) or not treated (control) with gibberellins (GA). With GA3 treatment, seeds germinated faster and to a higher percentage than control seeds. The +GA3 treatment increased total bioactive GA in the embryo during germination relative to the control. Abscisic acid (ABA) concentrations decreased gradually from D to G in both tissues. Embryos of G seeds had a lower ABA content than NG seeds in both treatments. The GA/ABA ratio in the embryo was significantly higher in G than NG seeds. The +GA3 treatment did not significantly affect the GA/ABA ratio in either treatment. Cytokinin content increased from dry to germinated seeds. Jasmonic acid (JA) increased and 1‐aminocyclopropane‐1‐carboylic acid (ACC) decreased after imbibition. In addition, α‐tocopherol and α‐tocotrienol decreased, while lipid peroxidation increased in the embryo during germination. We conclude that germination in macaw palm seed involves reductions in ABA content and, consequently, increased GA/ABA in the embryo. Furthermore, the imbibition process generates oxidative stress (as observed by changes in vitamin E and MDA). 相似文献
8.
Barbara Wciślińska 《Biologia Plantarum》1977,19(5):370-376
The seeds ofFraxinus excelsior L. were stratified at 17-20 °C (warm stratification), at 4-6 °C (cold stratification) and at alternating temperature (warm — cold stratification). The seeds subjected to warm stratification only, remained dormant. The seeds stratified only at 4-6 °C germinated gradually during a long period of time. The seeds subjected to warm — cold stratification, however, germinated with great intensity within a relatively short period of time. GA3 was shown to stimulate the growth of embryos markedly, and its effect on the germination of seeds depended on the temperature of stratification. GA3 applied during the cold stratification accelerated the removal of dormancy by shortening the period of stratification and by influencing the germination of seeds. The results obtained indicate a similarity between the effect of temperature 17-20 °C during the warm stratification and that of gibberellic acid. Both those factors applied separately affect favourably after-ripening of the embryos and accelerate the germination of seeds. 相似文献
9.
J. S. Cho B. K. Jang S. M. Lee I. J. Lee C. H. Lee 《Plant biology (Stuttgart, Germany)》2020,22(3):514-521
- Information on the optimal conditions to promote the germination of Lamprocapnos spectabilis (L.) Fukuhara seeds is limited; consequently, this study was conducted to establish the requirements to break seed dormancy and promote germination.
- The selected seeds had morphophysiological dormancy and had not begun embryo development. To study the dormancy breaking and embryo development processes, seeds were subjected to constant or changing temperature treatments during moist stratification.
- High temperature and humidity resulted in vigorous embryo growth, with the longest embryos occurring after 1 month of incubation at 20 °C. At 4 °C, the seeds required incubation period of at least 3 months to germinate. Embryo growth and germination were higher with changing high and low temperatures than under a constant temperature, and changing temperatures also considerably changed the endogenous hormone levels, embryo development and germination. Bioactive gibberellin (GA) content was higher in seeds incubated at 20 °C for 1 month, then at 4 °C for 2 months. The content of endogenous abscisic acid in seeds subjected to the same treatment decreased by 97.6% compared with that of the untreated seeds.
- Embryo growth and seed germination require changing high and low temperatures; however, exogenous GA3 could substitute for high temperatures, as it also causes accelerated germination. In this study, the seeds of L. spectabilis were identified as an intermediate simple type, a sub‐level of morphophysiologically dormant seeds.
10.
Plant development from microspore-derived embryos in oilseed rape as affected by chilling, desiccation and cotyledon excision 总被引:1,自引:0,他引:1
The present study evaluated the effects of chilling, partial desiccation, cotyledon excision and successive subculture of
microspore-derived embryos on plant development in oilseed rape (Brassica napus L.). The results showed that out of the five media, all the genotypes showed the best response when the embryos were cultured
on the half-strength Murashige and Skoog medium with 2.0 mg dm−3 benzylaminopurine. A cold treatment for 3 or 5 d further increased frequencies of embryo germination (90.0 %) and plantlet
development (58.46 %). Desiccation for one day also increased the embryo germination and plantlet development in all genotypes
tested. Cutting the cotyledons of the embryos at late cotyledonary stage significantly increased the frequency of plantlet
development. The highest rate of plantlet development was obtained from cultures of embryos sampled with size of less than
4.0 mm. The successive subculture further improved the germination and development of plantlets from embryos. In the genotype
ZJU452, the rate of plantlet development reached 99.78 % after the second subculture of embryos. 相似文献
11.
The N-substituted phthalimide AC 94377 (1-(3-chlorophthalimido)-cyclohexanecarboxamide) was equally effective as a mixture of the gibberellins A4 and A7 (GA4/7) in breaking dormancy and stimulating germination of celery seeds when either was used in combination with ethephon or daminozide as a seed soak. Whereas seedlings emerging from GA4/7-treated seeds became etiolated in comparison with those from untreated seeds, those from AC 94377-treated seeds showed normal development. Preharvest sprays of gibberellic acid (GA3) increased the height of mature plants in comparison with untreated controls by about 16 per cent whereas AC 94377 was ineffective. The yield from GA3-treated plots was about 10 per cent greater than that from AC 94377-treated plots. 相似文献
12.
Background and Aims
Little is known about morphological (MD) or morphophysiological (MPD) dormancy in cold desert species and in particular those in Liliaceae sensu lato, an important floristic element in the cold deserts of Central Asia with underdeveloped embyos. The primary aim of this study was to determine if seeds of the cold desert liliaceous perennial ephemeral Eremurus anisopterus has MD or MPD, and, if it is MPD, then at what level.Methods
Embryo growth and germination was monitored in seeds subjected to natural and simulated natural temperature regimes and the effects of after-ripening and GA3 on dormancy break were tested. In addition, the temperature requirements for embryo growth and dormancy break were investigated.Key Results
At the time of seed dispersal in summer, the embryo length:seed length (E:S) ratio was 0·73, but it increased to 0·87 before germination. Fresh seeds did not germinate during 1 month of incubation in either light or darkness over a range of temperatures. Thus, seeds have MPD, and, after >12 weeks incubation at 5/2 °C, both embryo growth and germination occurred, showing that they have a complex level of MPD. Since both after-ripening and GA3 increase the germination percentage, seeds have intermediate complex MPD.Conclusions
Embryos in after-ripened seeds of E. anisopterus can grow at low temperatures in late autumn, but if the soil is dry in autumn then growth is delayed until snowmelt wets the soil in early spring. The ecological advantage of embryo growth phenology is that seeds can germinate at a time (spring) when sand moisture conditions in the desert are suitable for seedling establishment. 相似文献13.
Melissa Scholten Jacklyn Donahue Nancy L. Shaw Marcelo D. Serpe 《Annals of botany》2009,103(7):1091-1101
Background and Aims
Lomatium dissectum (Apiaceae) is a perennial, herbaceous plant of wide distribution in Western North America. At the time of dispersal, L. dissectum seeds are dormant and have under-developed embryos. The aims of this work were to determine the requirements for dormancy break and germination, to characterize the type of seed dormancy, and to determine the effect of dehydration after embryo growth on seed viability and secondary dormancy.Methods
The temperature requirements for embryo growth and germination were investigated under growth chamber and field conditions. The effect of GA3 on embryo growth was also analysed to determine the specific type of seed dormancy. The effect of dehydration on seed viability and induction of secondary dormancy were tested in seeds where embryos had elongated about 4-fold their initial length. Most experiments examining the nature of seed dormancy were conducted with seeds collected at one site in two different years. To characterize the degree of variation in dormancy-breaking requirements among seed populations, the stratification requirements of seeds collected at eight different sites were compared.Key Results
Embryo growth prior to and during germination occurred at temperatures between 3 and 6 °C and was negligible at stratification temperatures of 0·5 and 9·1 °C. Seeds buried in the field and exposed to natural winter conditions showed similar trends. Interruption of the cold stratification period by 8 weeks of dehydration decreased seed viability by about 30 % and induced secondary dormancy in the remaining viable seeds. Comparison of the cold stratification requirements of different seed populations indicates that seeds collected from moist habitats have longer cold stratification requirements that those from semiarid environments.Conclusions
Seeds of L. dissectum have deep complex morphophysiological dormancy. The requirements for dormancy break and germination reflect an adaptation to trigger germination in late winter.Key words: Apiaceae, cold stratification, Lomatium dissectum, morphophysiological dormancy, secondary dormancy, seed germination 相似文献14.
Summary Dormancy in intact seeds of Ruellia humilis is broken by chilling or by treatment with gibberellic acid (GA3). Embryos are nondormant and will grow when the seed coat is removed completely. Embryos from chilled or GA3-treated seeds have more growth potential than embryos from nontreated seeds. Dormancy is ascribed to the mechanical restriction of the embryo by the seed coat. Chilling and treatment with GA3 break dormancy by increasing the expansive force of the embryo; thus, chilled or GA3-treated embryos exert enough expansive force to break through the seed coat, whereas nontreated embryos do not.This work was supported by an NIH Biomedical Sciences Support Grant to the University of Kentucky. 相似文献
15.
Dissecting seed dormancy and germination in Aquilegia barbaricina,through thermal kinetics of embryo growth
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M. Porceddu E. Mattana H. W. Pritchard G. Bacchetta 《Plant biology (Stuttgart, Germany)》2017,19(6):983-993
- Threshold‐based thermal time models provide insight into the physiological switch from the dormant to the non‐dormant germinating seed.
- This approach was used to quantify the different growth responses of the embryo of seeds purported to have morphophysiological dormancy (MPD) through the complex phases of dormancy release and germination. Aquilegia barbaricina seeds were incubated at constant temperatures (10–25 °C) and 25/10 °C, without pre‐treatment, after warm+cold stratification (W+C) and GA3 treatment. Embryo growth was assessed and the time of testa and endosperm rupture scored. Base temperatures (Tb) and thermal times for 50% (θ50) of embryo growth and seed germination were calculated.
- W+C enabled slow embryo growth. W+C and GA3 promoted rapid embryo growth and subsequent radicle emergence. The embryo internal growth base temperature (Tbe) was ca. 5 °C for W+C and GA3‐treated seeds. GA3 treatment also resulted in similar Tb estimates for radicle emergence. The thermal times for embryo growth (θe50) and germination (θg50) were four‐ to six‐fold longer in the presence of GA3 compared to W+C.
- A. barbaricina is characterised by a multi‐step seed germination. The slow embryo growth during W+C reflects continuation of the maternal programme of development, whilst the thermal kinetics of both embryo and radicle growth after the removal of physiological dormancy are distinctly different. The effects of W+C on the multiphasic germination response in MPD seeds are only partially mimicked by 250 mg·l?1 GA3. The thermal time approach could be a valid tool to model thermal kinetics of embryo growth and radicle protrusion.
16.
Aruncus dioicus (Walter) Fernald (Rosaceae) is a perennial herbaceous plant whose young shoots are traditionally collected in the wild and consumed as a food in NE Italy. The aim of this study was to determine the germination requirements of its seeds in order to start its cultivation, and to assess the germination of six accessions of the species. Viability of seeds ranged from 86 to 97% in the various accessions. Germination rate was almost null in seeds of two accessions, and ranged from 10.5 to 37.3 in the other ones. The seed coat was permeable to water. Treatments with GA3, KNO3 and mechanical scarification did not enhance the germination, while the cold stratification treatment at 2 °C for different periods improved the germination rate and the mean germination time as compared with the untreated seeds. With 45 days of cold stratification, the germination rate and mean germination time (respectively, 90.1% and 7.7 dd) of seeds were different from those of the untreated seeds. Cold stratified seeds germinated under artificial light and did not germinate in the dark. Seeds of A. dioicus displayed an intermediate physiological dormancy, removable by a cold stratification treatment, requiring both light and cold conditions. 相似文献
17.
Embryos isolated from dormant apple seeds were treated with jasmonic acid (JA), gibberellin A3 (GA3), abscisic acid (ABA) and hydrogen cyanide in darkness and in light. The chemicals were present in the culture medium continuously and simultaneously or applied for 2 days and in different sequences. All treatments stimulated embryo germination except ABA, which was strongly inhibitory. Additive effects of JA with light and with GA3 on embryo germination were observed, whereas ABA interacted synergically with JA, HCN and light. ABA and GA3 were most effective when applied early during embryo incubation, but the late JA treatment was more stimulatory. It is concluded that JA does not act on the regulatory pathway that is initiated by light and which leads to embryo germination through gibberellin accumulation and alkaline lipase activation. ABA and HCN appear to be involved in the control of this pathway. JA and ABA may be involved in the control of alkaline lipase activity, independently of this regulatory chain.Abbreviations ABA
abscisic acid
- GA3
gibberellin A3
- JA
jasmonic acid 相似文献
18.
Red light (R) and gibberellins (GA) each induce a water potential decrease in the axes of lettuce (Lactuca sativa L.) embryos resulting in germination of intact seeds (achenes) or an increase in growth of the axes of isolated embryos. The fruit coat and endosperm are a substantial barrier to the penetration of exogeneous GA. Isolated embryos take up 35 times as much [3H]GA1 as the embryos of intact seeds and respond to less than 1·10-10 M GA3 or GA4+7. We calculated that only 1·10-8 M of either GA3 or GA4+7 would result in 50% germination if the GA were able freely to penetrate the fruit coat. Exogenous GA3 or GA4+7, at concentrations insufficient to cause germination, result in an apparent synergistic promotion of germination when suboptimal R is applied. Yet suboptimal concentrations of exogenous GA3 or GA4+7 and suboptimal R result in only additive increases in the growth response in axes of isolated embryos. Dose-response curves demonstrate quantitative increases in the growth response of the isolated axes after R or GA treatments insufficient to induce germination in intact seeds, indicating that a threshold potential must be achieved by the embryonic axes before germination can occur.Abbreviations FR
far=red light
- GA
gibberellin
- PEG
poly-ethylene glycol 4000
- Pfr
far-red-absorbing phytochrome
- R
red light
III.=Carpita et al. 1979b; IV.=Carpita et al. 1979c 相似文献
19.
Delong Yang Wei Li Sheng Li Xiuling Yang Jiling Wu Ziyi Cao 《Plant Growth Regulation》2007,51(1):63-71
The purpose of this study was to understand factors affecting in vitro embryo rescue culture from hybrids between diploid
and tetraploid varieties of grape in creation new triploid germplasm resources. The effects of different media, removal ages
of immature seeds and reciprocal crosses of parents on the germination and seedling survival of immature seeds from crosses
between diploid and tetraploid grape varieties by in vitro embryo rescue culture were investigated. The results indicated
that the medium consisting of NN-1969 + IAA 1.75 mg l−1 + GA3 0.35 mg l−1 + CH 400 mg l−1 + AC 2.0 g l−1 was better than other media. The optimal removal age of immature seeds for the best development of embryos was 35–45 days
after pollination (DAP). The percentage of germination (PG) for immature seeds and the percentage of seedling survival (PSS)
for immature seeds for diploid varieties used as female parents were 10.72% and 4.35% higher than when tetraploid varieties
were used as female parents respectively. A total of 41 hybrid progenies from eight combinations were obtained, made up of
17 diploid, 9 tetraploid, 14 aneuploid, and 1 triploid progeny as determined by root-tip chromosome identification. The triploid
progeny was from Fujiminori (2n = 4x = 76) × Jingxiu (2n = 2x = 38). These results implied that it was feasible to extend the hybridization range of grape and to create new germplasm
resources by in vitro embryo rescue based on the conventional hybridization. The NN-1969 medium supplemented with GA3 and IAA was more propitious to the development of immature seeds sampled at about 45 DAP. It was easier to obtain plants using
diploid as female parent, but triploid progeny was only obtained using tetraploid as female parent. 相似文献
20.
A. Pech y Aké B. Maust A. Orozco-Segovia C. Oropeza 《In vitro cellular & developmental biology. Plant》2007,43(3):247-253
The effect of gibberellic acid (GA3) was tested on germination of coconut zygotic embryos, their conversion into plantlets and ex vitro survival. There were four treatments consisting of 5 wk of culture in semi-solid medium or liquid medium, with or without
GA3. Embryos were then transferred to GA3 free-liquid medium for the rest of a 32-wk culture. Germination and conversion percentages were higher in semi-solid medium
than in liquid medium, and with both media percentages increased with GA3 treatment (with the exception of the highest GA3 concentration). Embryos of two varieties (MGD and MYD) were used. The following are the results with MGD embryos. Optimum
GA3 concentration in liquid medium was 0.46 μM, with 80% germination (62% in the control without GA3) and 4.6 μM in semi-solid medium with 98% germination (71% in the control). With GA3 treatment, germination was also faster. Conversion in semi-solid medium with GA3 was 87% (60% in the control), and 45% in liquid medium with GA3 (25% in the control). Once the plantlets had at least three bifid leaves and three primary roots at the time of transfer
to ex vitro, they survived independently of the treatment. When MYD embryos were used, germination and conversion percentages were higher
in semi-solid medium than in liquid medium, and they increased when GA3 was used, although percentages were lower than those obtained with MGD embryos. The results showed that the use of GA3 benefited coconut embryos in culture because it favored germination and conversion to plants on semi-solid medium, and hence
improved previous protocols. 相似文献