CHEMICAL CONSTITUENTS IN WILD OAT (Avenu fatua) HULLS AND THEIR EFFECTS ON SEED GERMINATION

1982 ◽  
Vol 62 (1) ◽  
pp. 155-161 ◽  
Author(s):  
FRANK S. CHEN ◽  
JOHN M. MacTAGGART ◽  
RICHARD M. ELOFSON
Keyword(s):  
Seed Germination ◽  
Chemical Constituents ◽  
Short Chain Fatty Acids ◽  
Inhibitory Effect ◽  
Water Soluble ◽  
Nonanoic Acid ◽  
Lettuce Seed ◽  
Wild Oat ◽  
Phenolic Inhibitor ◽  
Lettuce Seed Germination

Aqueous extracts of dormant wild oat (Avena fatua L.) hulls had a weak inhibitory effect on lettuce seed germination. Both paper and thin layer chromatographic analyses of the ether-soluble acidic fraction showed the presence of phenolics and short-chain fatty acids. No abscisic acid was detected. Vanillin, protochatechualdehyde, p-coumaric acid, ferulic acid and caffeic acid were isolated from hull extracts. Vanillin was shown to be the main water-soluble phenolic inhibitor of lettuce seed germination. At a concentration higher than 6.6 × 10−3M, vanillin was found to be more inhibitory than nonanoic acid to both lettuce and wild oat germination. The concentration of phenolics in the hulls does not account for suppression of wild oat seed germination.

scholarly journals Ethylene evolution and endo-beta-mannanase activity during lettuce seed germination at high temperature

2004 ◽  
Vol 61 (2) ◽  
pp. 156-163 ◽  
Author(s):  
Warley Marcos Nascimento ◽  
Daniel James Cantliffe ◽  
Donald John Huber
Keyword(s):  
High Temperature ◽  
Seed Germination ◽  
Seed Priming ◽  
Inhibitory Effect ◽  
Lettuce Seed ◽  
Ethylene Evolution ◽  
Radicle Protrusion ◽  
Mannanase Activity ◽  
Lettuce Seed Germination ◽  
Dark Green

High temperatures during lettuce seed imbibition can delay or completely inhibit germination and the endosperm layer appears to restrict the radicle protrusion. The role of endo-beta-mannanase during lettuce seed germination at 35°C and the influence of ethylene in endo-beta-mannanase regulation were investigated. Seeds of 'Dark Green Boston' (DGB) and 'Everglades' (EVE) were germinated in water, or 10 mmol L-1 of 1-aminocyclopropane-1-carboxylic acid (ACC), or 10 mmol L-1 of aminoethoxyvinylglycine (AVG), or 20 mmol L-1 of silver thiosulphate (STS). Seeds were also primed in polyethylene glycol (PEG), or PEG + ACC, PEG + AVG, or PEG + STS. Untreated seeds germinated 100% at 20°C. At 35°C, EVE seeds germinated 100%, whereas DGB seeds germinated only 33%. Seed priming or adding ACC during incubation increased germination at 35°C. Higher ethylene evolution was detected in EVE than in DGB during germination at 35°C. AVG did not inhibit seed germination of DGB at 35°C, but STS did. Higher endo-beta-mannanase activity was observed in EVE compared with DGB seeds. Providing ACC either during priming or during germination increased endo-beta-mannanase activity, whereas AVG and STS led to decreased or no activity. Ethylene may overcome the inhibitory effect of high temperature in thermosensitive lettuce seeds due to increased endo-beta-mannanase, possibly leading to weakening of the endosperm.

scholarly journals Ethylene and lettuce seed germination

2003 ◽  
Vol 60 (3) ◽  
pp. 601-606 ◽  
Author(s):  
Warley Marcos Nascimento
Keyword(s):  
High Temperature ◽  
Seed Germination ◽  
Critical Factor ◽  
Inhibitory Effect ◽  
Lettuce Seed ◽  
A Cell ◽  
Lettuce Seed Germination ◽  
Exogenous Ethylene ◽  
Increased Activity

Ethylene can stimulate seed germination and overcome dormancy in many species. For instance, the inhibitory effect of high temperature on lettuce seed germination can be overcome by exogenous ethylene. Involvement of ethylene in seed germination is a widely accepted fact, but the mechanistic details are poorly understood. A critical factor in ethylene studies is the response of seed germination properties to various ethylene inhibitors. Lettuce seed has been used as a model to study the role of ethylene in seed germination at high temperature. The role of ethylene in germination is not known but either ethylene evolution or addition of 1-aminocyclopropane-1-carboxilic acid (ACC) have been associated with increased activity of endo-beta-mannanase, a cell-wall enzyme that weakens the endosperm and allows lettuce seed to germinate at high temperature. This review describes some results on seed germination studies in response to ethylene and its possible role in promoting germination at high temperature.

scholarly journals Water-Soluble Carbon Nanoparticles Improve Seed Germination and Post-Germination Growth of Lettuce under Salinity Stress

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1192 ◽  
Author(s):  
Hanna Baz ◽  
Matthew Creech ◽  
Jianjun Chen ◽  
Haijun Gong ◽  
Kent Bradford ◽  
...  
Keyword(s):  
Seed Germination ◽  
Salinity Stress ◽  
Carbon Nanoparticles ◽  
Crop Production ◽  
Water Soluble ◽  
Developmental Phase ◽  
Lettuce Seed ◽  
Primary Roots ◽  
Lettuce Seed Germination ◽  
Soluble Carbon

Seed germination is a critical developmental phase for seedling establishment and crop production. Increasing salinity stress associated with climatic change can pose a challenge for seed germination and stand establishment of many crops including lettuce. Here, we show that water soluble carbon nanoparticles (CNPs) can significantly promote seed germination without affecting seedling growth. Twenty-seven varieties of lettuce (Lactuca sativa) were screened for sensitivity to germination in 150 and 200 mM NaCl, and six salt-sensitive varieties (Little Gem, Parris Island, Breen, Butter Crunch, Muir, and Jericho) were selected and primed with 0.3% soluble carbon nanoparticles. Pretreatment with CNPs significantly improved seed germination under 150 mM NaCl and high temperature. CNP treatment slightly inhibited the elongation of primary roots but promoted lateral root growth and accumulation of chlorophyll content of seedlings grown under salt stress. Despite different lettuce varieties exhibiting a distinct response to nanoparticle treatments, results from this study indicate that soluble nanoparticles can significantly improve lettuce seed germination under salinity stress, which provide fundamental evidence on the potential of nanoparticles in agricultural application to improve crop yield and quality under stressful conditions.

scholarly journals Preventing thermoinhibition in a thermosensitive lettuce genotype by seed imbibition at low temperature

2003 ◽  
Vol 60 (3) ◽  
pp. 477-480 ◽  
Author(s):  
Warley Marcos Nascimento
Keyword(s):  
Seed Germination ◽  
Low Temperature ◽  
High Temperatures ◽  
Lactuca Sativa ◽  
Lettuce Seed ◽  
Temperature Dependent ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Lettuce Seed Germination ◽  
Dark Green

Lettuce (Lactuca sativa L.) seed germination is strongly temperature dependent and under high temperatures, germination of most of genotypes can be erratic or completely inhibited. Lettuce seeds of 'Dark Green Boston' (DGB) were incubated at temperatures ranging from 15° to 35°C at light and dark conditions. Other seeds were imbibed in dark at 20°; 25°; 30°; and 35°C for 8 and 16 hours and then transferred to 20 or 35°C, in dark. Seeds were also incubated at constant temperature of 20° and 35 °C, in the dark, as control. In another treatment, seeds were primed for 3 days at 15°C with constant light. DGB lettuce seeds required light to germinate adequately at temperatures above 25°C. Seeds incubated at 20°C had 97% germination, whereas seeds incubated at 35°C did not germinate. Seeds imbibed at 20°C for 8 and 16 hours had germination. At 35°C, seeds imbibed initially at 20°C for 8 and 16 hours, had 89 and 97% germination, respectively. Seeds imbibed at 25°C for 16 hours, germinated satisfactory at 35°C. High temperatures of imbibition led to no germination. Primed and non-primed seeds had 100% germination at 20°C. Primed seeds had 100% germination at 35°C, whereas non-primed seeds germinate only 4%. The first hours of imbibition are very critical for lettuce seed germination at high temperatures.

Dichloromethane and Lettuce Seed Germination

Science ◽  
1973 ◽  
Vol 179 (4068) ◽  
pp. 96-96
Author(s):  
H. Meyer ◽  
A. M. Mayer
Keyword(s):  
Seed Germination ◽  
Lettuce Seed ◽  
Lettuce Seed Germination
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