Effects of Water Deficits on First Periderm and Xylem Development in Fraxinuspennsylvanica

1972 ◽  
Vol 2 (2) ◽  
pp. 144-151 ◽  
Author(s):  
G. A. Borger ◽  
T. T. Kozlowski
Keyword(s):  
Polyethylene Glycol ◽  
Seed Germination ◽  
Secondary Xylem ◽  
Water Deficits ◽  
Xylem Development ◽  
Germinating Seeds ◽  
Periderm Formation

Three-day-old seedlings of Fraxinuspennsylvanica were transferred to soil undergoing periodic drying or continuous subirrigation. Seedlings were harvested after 24 days. Germinating seeds of F. pennsylvanica were exposed to 1, 10, 20, or 30% polyethylene glycol (PEG) for 35 days and 1-day-old seedlings were exposed to 1, 10, or 20% PEG for 35 days. Seedlings grown on drying cycles or in 20% PEG had smaller periderm and xylem increments than seedlings grown in continuously subirrigated soil or 1 or 10% PEG, respectively. Xylem increment was affected more than periderm increment by water deficits. Germinating seeds exposed to 10 or 20% PEG did not develop periderm or secondary xylem and did not expand foliage. Thirty per cent PEG caused desiccation and death of germinating seeds. Seeds exposed to 1% PEG germinated and developed normally. When water deficits occurred during germination the foliage failed to expand and periderm formation was thereby prevented. Water deficits subsequent to seed germination reduced periderm increment less than they reduced xylem increment, indicating difference in physiological controls.

Effects of Light Intensity on Early Periderm and Xylem Development in Pinusresinosa, Fraxinuspennsylvanica, and Robiniapseudoacacia

1972 ◽  
Vol 2 (3) ◽  
pp. 190-197 ◽  
Author(s):  
G. A. Borger ◽  
T. T. Kozlowski
Keyword(s):  
Seed Germination ◽  
Light Intensity ◽  
Secondary Xylem ◽  
Xylem Development

The influence of light intensity on development of the first periderm and xylem in seedlings of Pinusresinosa, Fraxinuspennsylvanica, and Robiniapseudoacacia up to 56 days after seed germination was studied. Dark-grown seedlings of all three species lacked periderm at the end of the experimental periods, emphasizing the essentiality of light for periderm development. P. resinosa seedlings grown for 56 days following germination at 70 ft-c (1 ft-c = 10.76 lm/m2) of light and R. pseudoacacia seedlings grown at 70 or 300 ft-c of light for 30 days following germination failed to develop periderm. Seedlings of F. pennsylvanica grown at 70, 300, 600 or 1200 ft-c of light for 30 days following germination developed periderm. Periderm increments did not differ in 56-day-old P. resinosa seedlings grown at 600 or 1200 ft-c or in 30-day-old F. pennsylvanica seedlings grown at 70 or 300 ft-c of light. Phellogen formed sooner and was more active in 30-day-old R. pseudoacacia seedlings grown at 1200 ft-c than in those grown at 600 ft-c. Time to periderm initiation decreased and phellem increment increased in 30-day-old F. pennsylvanica seedlings with each increase in light intensity from 300 to 1200 ft-c. Secondary xylem was absent in dark-grown seedlings of all three species and in P. resinosa and F. pennsylvanica seedlings grown at 70 ft-c of light. In other treatments xylem increment increased significantly with each increase in light intensity up to 1200 ft-c.

scholarly journals Auxin‐mediated Aux/ IAA ‐ ARF ‐ HB signaling cascade regulates secondary xylem development in Populus

2019 ◽  
Vol 222 (2) ◽  
pp. 752-767 ◽  
Author(s):  
Changzheng Xu ◽  
Yun Shen ◽  
Fu He ◽  
Xiaokang Fu ◽  
Hong Yu ◽  
...  
Keyword(s):  
Secondary Xylem ◽  
Signaling Cascade ◽  
Xylem Development

scholarly journals Adaptive drought tolerance during germination of Salsola drummondii seeds from saline and nonsaline habitats of the arid Arabian deserts

Botany ◽  
2019 ◽  
Vol 97 (2) ◽  
pp. 123-133 ◽  
Author(s):  
Attiat Elnaggar ◽  
Ali El-Keblawy ◽  
Kareem A. Mosa ◽  
Teresa Navarro
Keyword(s):  
Polyethylene Glycol ◽  
Seed Germination ◽  
Drought Tolerance ◽  
Light Regimes ◽  
Saline Habitats ◽  
Population Origin ◽  
Effects Of Temperature ◽  
Osmotic Potentials

The effects of temperature, light, salinity, and drought on germination of halophytes have been extensively studied. However, few studies have focused on the germination of plants that grow well in both saline and nonsaline habitats (i.e., habitat-indifferent halophytes). Here, we assess the impacts of population origin, temperature, and light on drought tolerance, as simulated with polyethylene glycol (PEG), during germination of Salsola drummondii Ulbr., a habitat-indifferent halophyte from the arid Arabian deserts. Seeds were collected from both saline and nonsaline habitats and germinated at six concentrations of PEG at three temperatures and two light regimes. An increase in the concentration of PEG resulted in a significant reduction in seed germination, especially at higher temperatures. Seeds from the nonsaline habitat attained significantly greater germination efficiency at concentrations of PEG up to –1.2 MPa, but there was no difference in germination of seeds between the two habitats at concentrations of –1.5 MPa. Seeds from the saline habitat germinated significantly faster at higher concentrations of PEG. Germination was significantly higher in darkness than in light at –1.5 MPa at the lower temperatures, but the opposite was true for the higher temperatures. Seeds from saline habitats had higher levels of dormancy and faster rates of germination at higher concentrations of PEG because of their adaptation to low osmotic potentials.

scholarly journals Effects of Matric and Osmotic Priming Treatments on Broccoli Seed Germination

1996 ◽  
Vol 121 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Lewis W. Jett ◽  
Gregory E. Welbaum ◽  
Ronald D. Morse
Keyword(s):  
Polyethylene Glycol ◽  
Seed Germination ◽  
Root Growth ◽  
Growth Rates ◽  
Germination Rate ◽  
Membrane Integrity ◽  
Seed Vigor ◽  
Radicle Emergence ◽  
The Mean ◽  
Peg 8000

Priming, a controlled-hydration treatment followed by redrying, improves the germination and emergence of seeds from many species. We compared osmotic and matric priming to determine which was the most effective treatment for improving broccoli seed germination and to gain a greater understanding of how seed vigor is enhanced by priming. Broccoli (Brassica oleracea L. var. italica) seeds were osmotically primed in polyethylene glycol (PEG 8000) at -1.1 MPa or matrically primed in a ratio of 1.0 g seed:0.8 g synthetic calcium silicate (Micro-Cel E):1.8 ml water at -1.2 MPa. In the laboratory, germination rates and root lengths were recorded from 5 to 42C and 10 to 35C, respectively. Broccoli seeds germinated poorly at >35C. Root growth after germination was more sensitive to temperatures >30C and <15C than radicle emergence. Matric and osmotic priming increased germination rate in the laboratory, greenhouse, and field. However, matric priming had a greater effect on germination and root growth rates from 15 to 30C. Neither priming treatment affected minimum or maximum germination or root growth temperatures. Both priming treatments decreased the mean thermal time for germination by >35%. The greater germination performance of matrically primed seeds was most likely the result of increased oxygen availability during priming, increased seed Ca content, or improved membrane integrity.

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.

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 Priming Techniques on Seed Germination Characteristics of C. Maxima Duch

2011 ◽  
Vol 474-476 ◽  
pp. 36-39 ◽  
Author(s):  
Yong Dong Sun ◽  
Xin Zheng Li ◽  
He Lian Yang ◽  
Li Sun
Keyword(s):  
Polyethylene Glycol ◽  
Seed Germination ◽  
Seed Priming ◽  
Distilled Water ◽  
Nacl Solution ◽  
Peg 6000 ◽  
Germination Process ◽  
Germination Characteristics ◽  
Successful Technique

The present study was conducted to investigate the effect of seed priming techniques on germination characteristics of C. maxima Duch. cultivar (Beiguan). Treatments were combinations of 3 levels of priming (distilled water, NaCl and PEG6000) and non-priming (control) with 3 replications. Concentrations of NaCl solution were 50, 100, 150, 200 mmol•L-1, and polyethylene glycol (PEG) 6000 were 10%, 20%, 30%, 40%, respectively. Seeds were primed using the above priming materials for 24 hours at 20°C in the dark, respectively. The results showed that different priming techniques could have various effects on germination of Beiguan seeds. Hydropriming (distilled water), NaCl priming and PEG6000 priming (10%) all improved the germination characteristics of Beiguan, compared to the control. NaCl priming was more effective than hydropriming and PEG6000 priming and was the most successful technique in this study. These findings indicated that seed priming techniques could accelerate germination process and were simple and cheap, we should propose these methods to farmers.

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