scholarly journals Seed germination behaviour of the narrow endemic Daphne arbuscula (Thymelaeaceae) compared to the more widespread Daphne cneorum

2021 ◽  
Author(s):  
Alice Di Sacco ◽  
Zuzana Gajdošová ◽  
Marek Slovák ◽  
Ingrid Turisová ◽  
Peter Turis ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Quality ◽  
Seed Viability ◽  
Ex Situ ◽  
Cold Stratification ◽  
Seed Biology ◽  
Distribution Ranges ◽  
Different Temperatures ◽  
Limited Dispersal ◽  
Germination Behaviour

AbstractDiminished reproduction success in species with narrow distribution ranges might be one of the factors responsible for their limited dispersal and colonization abilities. We investigated here various aspects of the seed biology of the West Carpathian endemic Daphne arbuscula (Thymelaeaceae) and compared it with its more widespread relative D. cneorum. In both species, we investigated (i) differences in seed viability and germination ability; (ii) differences between the two observed fruit morphotype groups, and (iii) the effect of cold stratification in breaking seed dormancy and enhance germination in stored seeds. To determine seed viability, a tetrazolium test and an imbibed cut test were performed. Several seed germination tests with gibberellic acid and with a sequence of cold and warm stratification, using different temperatures and durations, were carried out. We uncovered that (i) D. arbuscula seeds show significantly lower viability than D. cneorum seeds, but this difference is due to the smaller-fruit morphotype; (ii) seed quality and viability of the big-fruit morphotype are significantly greater than the smaller-fruit morphotype in both species, although the seed viability of the latter is not null and the dormancy level seems to differ between them; (iii) a warm stratification at 15°C for 13 weeks, followed by cold stratification at either 0 or 5°C for 28 weeks, followed by 4 weeks at 15°C, break physiological dormancy and allow the majority of seeds of D. arbuscula (63%) to germinate. We recommend including both fruit morphotypes when collecting seed of Daphne for ex situ conservation and reintroduction initiatives, to maintain the original genetic diversity of the species.

scholarly journals Seed germination of Carex lainzii Luceño, E. Rico & T. Romero: An endemic Spanish endangered species

2019 ◽  
Vol 20 (3) ◽  
pp. 704-711
Author(s):  
KAROLINE APARECIDA FELIX RIBEIRO ◽  
CRISTIAN MADEIRA DE MEDEIROS ◽  
JOSÉ ÁNGEL SÁNCHEZ-AGUDO ◽  
JOSÉ SÁNCHEZ-SÁNCHEZ
Keyword(s):  
Seed Germination ◽  
Endangered Species ◽  
Ex Situ Conservation ◽  
Seed Viability ◽  
Potassium Nitrate ◽  
Ex Situ ◽  
Cold Stratification ◽  
Different Temperatures ◽  
Two Populations

Abstract. Ribeiro KAF, Madeira de Medeiros C, Agudo JAS, Sánchez JS. 2019. Seed germination of Carex lainzii Luceño, E. Rico & T. Romero: An endemic Spanish endangered species. Biodiversitas 20: xxxx. Strategies to halt the decline of biodiversity include: in-situ and ex-situ conservation, the latter already considered at the global level essential in conservation programs. The results of the germinative responses of Carex lainzii Luceño, E. Rico & T. Romero (Cyperaceae), an endemic Spanish endangered species, are presented in this work, to different trials carried out in the laboratory with seeds harvested in the two known populations of that community. Treatments with and without 0.2% potassium nitrate (KNO3) were tested for four, six and eight months in cold stratification at 5 °C in two germination chambers at different temperatures (22/10 °C and 27/15 °C with a photoperiod of 12/12 hours). The results indicate that there is a large difference in germination rates between the two populations. The use of KNO3 did not increase germination rates in any case, but differences were found between periods of cold stratification, with six months being the most effective. On the other hand, the germination rates of both populations remain low (17.58% and 2%) compared to the obtained rate of seed viability. With this first approach to the understanding of the germination requirements of C. lainzii, it becomes clear that new essays are needed to obtain better results, in order to effectively implement the protection plans of C. lainzii populations.

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.

Gentiana lutea L. subsp. lutea seed germination: natural versus controlled conditions

Botany ◽  
2016 ◽  
Vol 94 (8) ◽  
pp. 653-659 ◽  
Author(s):  
Alba Cuena-Lombraña ◽  
Marco Porceddu ◽  
Caterina Angela Dettori ◽  
Gianluigi Bacchetta
Keyword(s):  
Seed Germination ◽  
Cold Stratification ◽  
Remarkable Effect ◽  
Thermal Requirements ◽  
Gentiana Lutea ◽  
Controlled Conditions ◽  
Different Temperatures ◽  
Soil Temperatures ◽  
Germination Behaviour ◽  
European Mountains

Gentiana lutea L. subsp. lutea is a geophyte that occurs in the central-southern European mountains. We investigated its germination ecophysiology with the main aim of evaluating seed germination behaviour under controlled and natural conditions. Seeds from four natural sites were tested for germination requirements under a range of different temperatures, and by comparing the results with those obtained under both cold stratification at 5 °C and treatment with GA3. We simultaneously carried out germination tests at each collecting site, and soil temperatures were recorded. Our results indicate that germination under controlled conditions is limited by high temperatures (25 °C), below which GA3 has a remarkable effect on germination percentages. Cold stratification did not have an influence on the germination response, thus suggesting that a temperature of 5 °C is not sufficient to break seed dormancy; this result was supported by soil temperatures. Gentiana lutea created a short-term persistent seed bank, and seeds mainly germinated in their first year. The germination under controlled conditions was similar in all accessions, while different responses were found in the field, where a potential influence of the aspect was observed. These findings underscore the importance of understanding germination behaviour in the field to define the real thermal requirements of a taxon.

scholarly journals Seed longevity of maize conserved under germplasm bank conditions for up to 60 years

2021 ◽  
Author(s):  
Filippo Guzzon ◽  
Maraeva Gianella ◽  
Jose Alejandro Velazquez Juarez ◽  
Cesar Sanchez Cano ◽  
Denise E Costich
Keyword(s):  
Seed Germination ◽  
Plant Genetic Resources ◽  
Seed Viability ◽  
Storage Conditions ◽  
Seed Longevity ◽  
Germplasm Bank ◽  
Significant Difference ◽  
Different Temperatures ◽  
Germination Experiments

Abstract Background and Aims The long-term conservation of seeds of plant genetic resources is of key importance for food security and preservation of agrobiodiversity. Nevertheless, there is scarce information available about seed longevity of many crops under germplasm bank conditions. Methods Through germination experiments as well as the analysis of historical monitoring data, we studied the decline in viability manifested by 1000 maize (Zea mays subsp. mays) seed accessions conserved for an average of 48 years at the CIMMYT germplasm bank, the largest maize seedbank in the world, under two cold storage conditions: an active (–3 °C; intended for seed distribution) and a base conservation chamber (–15 °C; for long-term conservation). Key Results Seed lots stored in the active chamber had a significantly lower and more variable seed germination, averaging 81.4 %, as compared with the seed lots conserved in the base chamber, averaging 92.1 %. The average seed viability detected in this study was higher in comparison with that found in other seed longevity studies on maize conserved under similar conditions. A significant difference was detected in seed germination and longevity estimates (e.g. p85 and p50) among accessions. Correlating seed longevity with seed traits and passport data, grain type showed the strongest correlation, with flint varieties being longer lived than floury and dent types. Conclusions The more rapid loss of seed viability detected in the active chamber suggests that the seed conservation approach, based on the storage of the same seed accessions in two chambers with different temperatures, might be counterproductive for overall long-term conservation and that base conditions should be applied in both. The significant differences detected in seed longevity among accessions underscores that different viability monitoring and regeneration intervals should be applied to groups of accessions showing different longevity profiles.

Seed Longevity and Germination Behaviour in Eugenia roxburghii

2021 ◽  
Vol 27 (3) ◽  
pp. 167-171
Author(s):  
Shareef Muhammed ◽  
Chitra Rajeswary ◽  
Anil Chandran
Keyword(s):  
Storage Temperature ◽  
Seed Viability ◽  
Seed Longevity ◽  
Ex Situ ◽  
Hermetic Storage ◽  
Germination Behaviour ◽  
Garden Plant ◽  
Relationship Of ◽  
The Relationship ◽  
And Storage

Eugenia roxburghii is an evergreen graceful shrub with a tremendous potential as garden plant. As a part of ex-situ conservation and popularization of the species, seed longevity was studied by understanding the relationship of seed viability with respect to different moisture contents and storage temperature. Seeds are recognized as recalcitrant, being desiccation as well as chilling sensitive. During hermetic storage, seeds stored at 300C/70%RH retained viability for about 5 months and 4 months in 200C/20% RH. Seeds can be best stored for five months in laboratory conditions.

scholarly journals The impact of temperature patterns during storage of Scots pine and Norway spruce seeds on their germination and fungal infection rates

2021 ◽  
Vol 182 (1) ◽  
pp. 157-167
Author(s):  
M. A. Nikolaeva ◽  
E. Yu. Varentsova ◽  
G. F. Safina
Keyword(s):  
Seed Germination ◽  
Seed Viability ◽  
Seed Storage ◽  
Pathogenic Fungi ◽  
Forest Tree ◽  
Ex Situ ◽  
Seed Infection ◽  
Germination Capacity ◽  
Long Term Storage ◽  
The Impact

Relevance of the study. One of the ways to maintain the genetic diversity of forest-forming species is to preserve highquality seed material ex situ. However, the relationship between the diversity of pathogenic mycobiota and the duration and methods of forest tree seed storage remains underexplored. The results of research into this problem can be used in forest seed production and forest phytopathology.Materials and methods. For our study we used seeds ofРinus sylvestris L. and Picea abies (L.) Karst. of the orthodox type, harvested in the period of 1996–2011 and stored under different temperatures: +20°С, +4°С, –18°С, and in liquid nitrogen vapor (–182°С) since 2011. Prior to their storage, seed samples were dried to a moisture content of 4.2–4.4% and hermetically packed. Seed germination was tested before and after three, five and eight years of storage, following GOST 13056.6-97 standards. The level of seed infection and the composition of pathogenic fungi were assessed.Results. After eight years of storage at +20°С, pine and spruce seed germination capacity decreased by 13–60%, depending on the year of harvesting. Seed storage at –18°С and –182°С allowed us to prevent seed infection and preserve seed viability. In most cases, the germination energy and germination capacity were negatively correlated with the level of seed infection. The diversity of pathogenic (mold) fungi on the surface of seeds was represented by ten genera; the most common were saprotrophs: Aspergillus P. Micheli, Penicillium Link, Rhizopus Ehrenb., Scopulariopsis Bainier.Conclusion. At the present stage of research, the success of seed storage at low and ultralow temperatures was demonstrated. We recommend cryopreservation for the long-term storage of improved and valuable seeds.

Seed survival in Chilean Nothofagus in response to desiccation and storage

2005 ◽  
Vol 15 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Pedro León-Lobos ◽  
Richard H. Ellis
Keyword(s):  
Moisture Content ◽  
Seed Quality ◽  
Seed Viability ◽  
Seed Storage ◽  
Forest Tree ◽  
Ex Situ ◽  
Hermetic Storage ◽  
Moisture Contents ◽  
Tree Seeds ◽  
Initial Seed

Nothofagus alpina,N. obliqua,N. glauca,N. leonii,N. dombeyiandN. pumilioseeds exhibited consistent, albeit slight, sensitivity to extreme desiccation, but nevertheless maintained viability at low moisture contents and cool temperatures (–10° to –20°C) over 2 years.Nothofagus alpina,N. obliqua,N. glauca,N. leoniiandN. dombeyiconformed to the seed viability equation of Ellis and Roberts; sensitivity of longevity to temperature was quantitatively similar to that of crop seeds, sensitivity to moisture was somewhat less, and a low-moisture-content limit to the equation was detected at 4.8% moisture content in hermetic storage at 65 °C, and possibly similar moisture contents at 30–40°C. These five species show orthodox seed storage behaviour. Therefore,ex-situconservation of theseNothofagusspecies in seed banks is possible, but the quality of seed lots collected requires attention. Seed storage behaviour was not defined inN. pumilio: initial seed quality was poor and loss of viability was detected over 2 years at 0°, –10° and –20°C at 2.7% moisture content, but not at 5.2%. The results confirm that the economy of nature in seed storage physiology extends to forest tree seeds, but the repeated observation of reduced sensitivity of longevity to moisture in forest tree seeds requires further investigation.

scholarly journals Seed germination, salt-stress tolerance, and the effect of nitrate on three Tyrrhenian coastal species of the Silene mollissima aggregate (Caryophyllaceae)

Botany ◽  
2015 ◽  
Vol 93 (12) ◽  
pp. 881-892 ◽  
Author(s):  
Valentina Murru ◽  
Andrea Santo ◽  
Carol Piazza ◽  
Laetitia Hugot ◽  
Gianluigi Bacchetta
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Seed Viability ◽  
Western Mediterranean ◽  
Ex Situ ◽  
Coastal Species ◽  
Western Mediterranean Basin ◽  
Salinity Levels ◽  
Optimum Period ◽  
Alternating Temperature

The Silene mollissima (L.) Pers. aggregate is part of section Siphonomorpha Otth. and currently comprises 11 narrow endemic species of the Western Mediterranean Basin. Three of these taxa (S. velutina Pourr. ex Loisel, S. ichnusae Brullo, De Marco & De Marco f., and S. badaroi Breistr.) have a distribution range centred in the northern Tyrrhenian area and occurring in coastal habitats. Inter- and intra-specific variability in the responses to light, constant (5–25 °C) and alternating temperatures (25/10 °C), salt (NaCl, 0–600 mmol/L), and levels of nitrate (KNO3, 20 mmol/L) under salt stress, as well as recovery of seed germination were evaluated for these species to more effectively support their in-situ and ex-situ conservation. Our results highlighted that the seeds of these three taxa were nondormant, and that light significantly improved their rate of germination, which was higher (>80%) at low temperatures (5–15 °C) and under the alternating temperature regime (25/10 °C), but decreased significantly at the highest temperature tested (25 °C). Seeds from Silene velutina and S. ichnusae germinated in up to 300 mmol/L NaCl, and S. badaroi germinated in up to 100 mmol/L. For all of the species except S. badaroi, salt did not affect seed viability, and recovery germination did not decrease with increasing salinity and temperature. Interpopulation variability, both in salt tolerance and recovery germination, was detected for S. velutina. The addition of KNO3 did not affect germination or recovery germination under salt conditions. The lack of effect from KNO3 suggests that nutrient availability is not a requirement for seed germination in these species. Our results show that all species experience an optimum period of germination during autumn–winter, which is when water availability is highest and soil salinity levels are minimal because of the Mediterranean rainfalls, but seeds from S. velutina and S. ichnusae will germinate up until spring.

Effects of partial drying on seed germination in the aquatic grasses Zizania palustris L. and Porteresia coarctata (Roxb.) Tateoka

1992 ◽  
Vol 2 (4) ◽  
pp. 199-205 ◽  
Author(s):  
C. D. Aldridge ◽  
R. J. Probert
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Growth Regulators ◽  
Germination Percentage ◽  
Hormonal Status ◽  
Cold Stratification ◽  
Porteresia Coarctata ◽  
Germination Response ◽  
Fold Reduction ◽  
Germination Behaviour

AbstractPartial drying of non-dormant seeds had little effect on germination behaviour compared with undried controls. In contrast, partial drying resulted in a marked increase in the germination response of freshly harvested (dormant) seeds of Z. palustris. Partial drying also resulted in a 100-fold reduction in the concentration of gibberellins (GA4+7) required for maximum germination. Although the concentration range of applied abscisic acid (ABA) that permitted germination was unaltered, partial drying increased the final germination percentage at all concentrations tested. The concentration of ABA above which germination was reduced in freshly harvested (dormant) seeds of Z. palustris was 3.16 × 10−7m compared with 10−4m in fresh (non-dormant) seeds of P. coarctata. Changes in the germination response of Z. palustris seeds to applied growth regulators, following partial drying or cold stratification might be explained by similar changes in hormonal status.

scholarly journals Quality assessment of Urochloa (syn. Brachiaria) seeds produced in Cameroon

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Njehoya Clémence-Aggy ◽  
Ntchapda Fidèle ◽  
Kana Jean Raphael ◽  
Etchu Kingsley Agbor ◽  
Sita R. Ghimire
Keyword(s):  
Seed Germination ◽  
Quality Assessment ◽  
Seed Quality ◽  
Seed Viability ◽  
Quality Parameters ◽  
North West ◽  
Grass Seed ◽  
Significant Relationships ◽  
Livestock Farmers

AbstractUrochloa (syn. Brachiaria) is the most popular fodder of livestock farmers in Cameroon for hay and seed productions. Farmers in Cameroon have been producing Brachiaria seeds for decades for own uses and surplus are sold to neighbours, and to traders from Cameroon and neighbouring countries. However, there is no information available about qualities of these seeds. Fifteen Urochloa seeds samples were collected from farmers and/or government stations in five regions (Adamaoua, East, North, North West, and West) and analysed for major seed quality parameters along with seeds of improved Urochloa cultivar Basilisk imported from Brazil as a check. Study showed significant differences among treatments for various seed quality parameters tested (P < 0.0001). The highest thousand grains weight was recorded in Basilisk (5.685 g), followed by W12 (3.555 g), A05 (3.153 g) and N01 (2.655 g). Caryopsis number and caryopsis weight were highest in Basilisk followed by E09, A06, and W12. Of three conditions tested for seed germination, mean germination was the highest in greenhouse (7.39%) where Basilisk had the highest germination (25.5%) followed by N01 (18.50%), A05 (14.50%) and W12 (12.75%). The seed viability ranged from 18% (E09) to 81% (N01), and there were a positive and highly significant relationships between seed germination and viability traits (r = 0.883; P < 0.0001). This study showed a marked difference in seed quality parameters of Urochloa grass seeds produced in Cameroon, and the potential of developing Urochloa grass seed business in the Northern, Adamaoua and Western regions of Cameroon.

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