scholarly journals Seed germination of Brazilian Aldama species (Asteraceae)

2015 ◽  
Vol 37 (3) ◽  
pp. 185-191 ◽  
Author(s):  
Aline Bertolosi Bombo ◽  
Tuane Santos de Oliveira ◽  
Beatriz Appezzato-da-Glória ◽  
Ana Dionísia da Luz Coelho Novembre
Keyword(s):  
Seed Germination ◽  
Reproductive Strategies ◽  
Fluorescent Lamp ◽  
Optimal Temperature ◽  
Embryo Viability ◽  
Seed Health ◽  
Sexual Propagation ◽  
Alternating Temperature ◽  
Underground System ◽  
Germinating Seeds

Brazilian samples from the Aldama genus (Asteraceae) could not propagate vegetatively despite their thickened underground system; thus, this study on sexual propagation is critical given the lack of data on reproductive strategies for such species. The aim for this research was to assess the optimal temperature for Aldama arenaria, A. filifolia, A. linearifolia, A. robustaand A. trichophylla seed germination. Seed germination was evaluated at the constant temperatures 20, 25 and 30 °C and the alternating temperatures 15-35, 20-30 and 20-35 °C with an 8-h daily photoperiod, using fluorescent-lamp. The ungerminated seeds were evaluated for embryo viability. The A. filifolia seed health was also evaluated. The optimal temperatures for germination are 20 and 25 °C for Aldama arenaria, A. filifolia, A. robusta and A. trichophylla seeds and 20 °C for A. linearifoliaseeds. The alternating temperature 15-35 °C is not recommended for germinating seeds from these species. The six fungi taxa studied herein did not affect A. filifolia seed germination.

Temperature/light interactions and the effect of seed source on germination of annual ryegrass (Lolium rigidum Gaud.) seeds

1976 ◽  
Vol 27 (6) ◽  
pp. 779 ◽  
Author(s):  
D Gramshaw
Keyword(s):  
Constant Temperature ◽  
Day Length ◽  
Maximum Temperature ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Average Temperature ◽  
Seed Sources ◽  
Alternating Temperature ◽  
Germinating Seeds ◽  
Temperature Optima

Germination of Lolium rigidum seeds, in the light (12 hr day length) and in the dark, was studied at constant and alternating (12/12 hr) temperatures in the range 8–35°C. Seeds had after-ripened for 22 weeks. Different constant temperature optima for germinability were found: 27° in light and 11° in dark. Germinability at alternating temperatures in darkness was determined solely by the minimum temperature of the alternation, and there was no response to thermoperiodicity per se. In contrast, light and alternating temperature appeared to interact to increase germinability, although the highest germinability occurred only when the maximum temperature was close to the optimum constant temperature, i.e. about 27°. Germination in both light and dark was most rapid where either the constant or the average temperature of an alternating regime was between 18 and 29°. Below 18° germination rates decreased markedly, and at 8°, rates were one-third of those at 18°. Seeds germinated more slowly in light than in darkness at all temperatures, but the differences were small relative to the effects of low temperatures.In another study, seeds collected from plants naturalized in eight different localities in the cereal belt of Western Australia and subsequently planted together in two contrasting environments were examined for germinability at 24/12°C in light and dark 18 weeks after harvest. Dark germinability differed between seed sources but not between planting sites, and ranged between 78 and 93%. Exposure of germinating seeds to light substantially alleviated dormancy in seeds from all sources.

scholarly journals Seed germination at different stratification temperatures and development of Phytelephas macrocarpa Ruiz & Pavón seedlings

2017 ◽  
Vol 39 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Sidney Alberto do Nascimento Ferreira ◽  
Daniel Felipe de Oliveira Gentil
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Viability ◽  
Seedling Development ◽  
Development Stages ◽  
Plastic Bags ◽  
Alternating Temperature

Abstract: Phytelephas macrocarpa (ivory palm) is an Amazonian palm vulnerable to exploitation pressure, as its seeds are widely used in regional handicrafts. The aims of this study were to evaluate the effectiveness of different stratification temperatures in overcoming seed dormancy and to analyze the seedling development stages of this species. In germination under stratification, the seeds were placed in plastic bags containing moistened vermiculite, and maintained at the constant temperatures of 25, 30, 35 and 40 °C, and an alternating temperature from 26 to 40 °C. In the study about the development of seedlings, seeds were sown in vermiculite under plastic cover (growing house), and the evolution of the seedling was evaluated, from the formation of germinative button to the complete blade expansion of the first eophyll. Stratification at alternating temperatures (26 to 40 °C) helped overcoming seed dormancy. Stratification at 25 °C kept the seed viability for nine months. Germination, characterized by the formation of the germinative button took an average of 114 ± 24 days, and the seedling development until the first extended eophyll lasted 244 ± 57 days.

scholarly journals Opportunistic Germination Behaviour of Gypsophila (Caryophyllaceae) in Two Priority Habitats from Semi-arid Mediterranean Steppes

2011 ◽  
Vol 39 (1) ◽  
pp. 18 ◽  
Author(s):  
Felix MORUNO ◽  
Pilar SORIANO ◽  
Oscar VICENTE ◽  
Monica BOSCAIU ◽  
Elena ESTRELLES
Keyword(s):  
Seed Germination ◽  
Climatic Conditions ◽  
Thermal Time ◽  
Distribution Area ◽  
Base Temperature ◽  
Additional Information ◽  
High Viability ◽  
Germination Behaviour ◽  
Alternating Temperature

Gypsophila tomentosa and G. struthium are closely related species, characteristic of two European priority habitats, salt and gypsum inland steppes, respectively. Germination strategies of the two taxa were investigated in plants from two nearby populations, growing under the same climatic conditions but on different types of soil, and belonging to different plant communities. Their germination patterns were studied at five constant temperatures in darkness: 5oC, 10oC, 15oC, 20oC and 25oC, and the base temperature and the thermal time requirement were calculated. As the distribution area of both species is subjected to a Mediterranean continental climate with significant differences between day and night, the possible preferences for an alternating temperature regime (25/10oC) were contrasted, as well as the influence of cold stratification and freezing. The effects on seed germination of light at constant 20oC and a 12/12 h photoperiod were also compared in the two species. The main conclusions of the work are the similarity of behaviour of both species, with an absence of seed dormancy, their opportunistic germination strategy, and water availability as the principal limitation to seed germination and plant establishment. The base temperature and thermal time indicate higher competitiveness of G. struthium at low temperatures, but seed germination of G. tomentosa is the most efficient at temperatures higher than 13.3oC. Optimal temperature and illumination conditions for nursery propagation depend on the species. The high viability of seeds observed after freezing prove the orthodox character of these seeds, providing additional information for long term seed conservation procedures.

scholarly journals Effects of Environmental Factors on Seed Germination and Emergence of Velvetleaf (Abutilon theophrasti)

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
RC. XIONG ◽  
Y. MA ◽  
HW. WU ◽  
WL. JIANG ◽  
XY. MA
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Field Experiments ◽  
Cropping Systems ◽  
Control Strategies ◽  
Seedling Emergence ◽  
Central China ◽  
Burial Depth ◽  
Temperature Regimes ◽  
Alternating Temperature

ABSTRACT: Velvetleaf, an annual broadleaf weed, is a common and troublesome weed of cropping systems worldwide. Laboratory and field experiments were conducted to determine the effects of environmental factors on germination and emergence of velvetleaf. Seeds germinated over a range of constant temperatures from 10 to 40 oC regardless of light conditions, but no germination occurred at temperature below 5 oC and beyond 50 oC. Seeds germinated at alternating temperature regimes of 15/5 to 40/30 oC, with maximum germination (>90%) at alternating temperatures of 40/30 oC. Germination was sensitive to water stress, and only 0.4% of the seeds germinated at the osmotic potential of -0.4 MPa. There was no germination at ? 0.6 MPa. Moreover, germination was reduced by saline and alkaline stresses and no germination occurred at ³ 150 mM NaCl or ³ 200 mM NaHCO3 concentrations. However, pH values from 5 to 9 had no effect on seed germination. Seedling emergence was significantly affected by burial depth and maximum emergence (78.1-85.6%) occurred at the 1-4 cm depth. The results of this study have contributed to our understanding of the germination and emergence of velvetleaf and should enhance our ability to improve control strategies in cropping systems in central China.

scholarly journals Acidovorax citrulli is sensitive to elevated temperatures during early stages of watermelon seed germination

2020 ◽  
Vol 48 (1) ◽  
pp. 11-20
Author(s):  
Mei Zhao ◽  
Ron Walcott
Keyword(s):  
Elevated Temperature ◽  
Seed Germination ◽  
Elevated Temperatures ◽  
Transmitted Disease ◽  
Effect Of Temperature ◽  
Crop Species ◽  
Inoculum Concentration ◽  
Bacterial Fruit Blotch ◽  
Acidovorax Citrulli ◽  
Germinating Seeds

Bacterial fruit blotch (BFB), caused by Acidovorax citrulli, is a seed-transmitted disease of cucurbit crop species. During seed-to-seedling transmission of BFB, A. citrulli initially grows as a saprophyte on germinating seeds and subsequently switches to a pathogenic mode. We investigated the effect of temperature on A. citrulli colonisation of germinating watermelon seeds. Seeds were vacuum-infiltrated with 106 CFU/ml A. citrulli, germinated at 28°C and 100% relative humidity, and transferred to 40°C at different times. Mean BFB incidence was significantly lower for seeds that were sown at 28°C and transferred to 40°C three days after sowing (DAS), compared with seeds incubated constantly at 28°C. Seeds showed reduced mean BFB transmission percentages when transferred from 28 to 40°C at 3 DAS, regardless of initial A. citrulli concentration. The effect of increased temperature on BFB seedling transmission was reversible regardless of the initial A. citrulli inoculum concentration. Furthermore, the A. citrulli population on germinating watermelon seedlings that were transferred from 28 to 40°C at 3 DAS was significantly lower than seedlings maintained at 28°C. We conclude that A. citrulli cells associated with germinating watermelon seeds are more sensitive to elevated temperature during the first 3 DAS relative to the later days.

scholarly journals Zinc Oxide and Zinc Oxide Nanoparticles Impact on In Vitro Germination and Seedling Growth in Allium cepa L.

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2784 ◽  
Author(s):  
Alicja Tymoszuk ◽  
Jacek Wojnarowicz
Keyword(s):  
Zinc Oxide ◽  
Seed Germination ◽  
Allium Cepa ◽  
Seedling Growth ◽  
Zinc Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Zno Nps ◽  
Allium Cepa L ◽  
Germinating Seeds

Zinc oxide nanoparticles (ZnO NPs) are ones of the most commonly manufactured nanomaterials worldwide. They can be used as a zinc fertilizer in agriculture to enhance yielding and to control the occurrence of diseases thanks to its broad antifungal and antibacterial action. The aim of this study was to investigate and compare the effects of ZnO submicron particles (ZnO SMPs) and ZnO NPs on the process of in vitro seed germination and seedling growth in onion (Allium cepa L. ‘Sochaczewska’), and to indicate the potential use of these compounds in onion production. In the experiment, disinfected seeds were inoculated on the modified Murashige and Skoog (MS) medium and poured with ZnO SMP or ZnO NP water suspension, at the concentrations of 50, 100, 200, 400, 800, 1600, and 3200 mg∙L−1. During three successive weeks, the germinating seeds were counted. Germination started most often on the second or third day of in vitro culture. The highest share of germination was recorded for seeds treated with 800 mg∙L−1 ZnO SMPs and ZnO NPs (52% and 56%, respectively). After the application of ZnO SMPs and ZnO NPs at the highest tested concentration (3200 mg∙L−1), the share of germinating seeds was only 19% and 11%, respectively. Interestingly, seedlings obtained from control seeds and seeds treated with ZnO SMPs and ZnO NPs did not differ statistically in terms of length, fresh weight, and dry weight of leaves, and roots. Both ZnO SMPs and ZnO NPs, in the concentration range from 50 to 1600 mg∙L−1, can be used to stimulate the germination process of onion seeds, without negative effects on the further growth and development of seedlings. There were no differences found between the action of ZnO NPs and ZnO SMPs, which suggested that the most important factor influencing seed germination was in fact the concentration of zinc ions, not the particle size.

Effect of light, salinity, and temperature on seed germination of Limonium stocksii

2004 ◽  
Vol 82 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Sabahat Zia ◽  
M Ajmal Khan
Keyword(s):  
Seed Germination ◽  
Temperature Regime ◽  
Germination Rate ◽  
Gradual Decrease ◽  
Salinity Treatment ◽  
Optimal Temperature ◽  
Complete Darkness ◽  
Temperature Regimes ◽  
Effect Of Light ◽  
Recovery Temperature

Limonium stocksii (Boiss.) Kuntze (Plumbaginaceae) is a perennial, woody shrub distributed at Hawks Bay, Karachi, Pakistan. Experiments were carried out to investigate seed germination responses of L. stocksii at different salinities (0, 100, 200, 300, 400, and 500 mmol/L NaCl) and under different temperature regimes (10:20, 15:25, 20:30, and 25:35 °C), both in a 12 h dark : 12 h light photoperiod and in complete darkness. The highest percentage of germination (about 100%) was obtained at 0, 100, and 200 mmol/L NaCl at 20:30 °C, and a further increase in salinity resulted in a gradual decrease in germination. Less than 5% of seeds germinated at 500 mmol/L NaCl. Germination under salinity treatment at 15:25 °C was slightly more inhibitory than the optimal temperature regime, whereas under both 10:20 and 25:35 °C temperature regimes, seed germination was substantially reduced and few seeds germinated at concentrations higher than 200 mmol/L NaCl. Germination rate was fastest at 20:30 °C and slowest at 10:20 °C. Relatively low seed germination was obtained in the dark in comparison to seeds germinated in a 12-h photoperiod under saline conditions. Recovery experiments showed that exposure of seeds to various salinity and temperature regimes had little effect on viability of seeds.Key words: germination, light, Limonium stocksii, NaCl, recovery, temperature.

Use of osmotic solutes to control seed germination of rice and common bean in seed health blotter tests

2008 ◽  
Vol 36 (1) ◽  
pp. 66-75 ◽  
Author(s):  
J.C. Machado ◽  
W.M. Coutinho ◽  
R.M. Guimarães ◽  
M.G.G.C. Vieira ◽  
D.F. Ferreira
Keyword(s):  
Seed Germination ◽  
Common Bean ◽  
Control Seed ◽  
Seed Health ◽  
Osmotic Solutes
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