scholarly journals Effects of Germination-promoting Substances Given in Conjunction with Red Light on the Phytochrome-mediated Germination of Dormant Lettuce Seeds (Lactuca sativa L.)

1974 ◽  
Vol 54 (6) ◽  
pp. 852-854 ◽  
Author(s):  
Henry L. Speer ◽  
Andrew I. Hsiao ◽  
William Vidaver
Keyword(s):  
Lactuca Sativa ◽  
Red Light ◽  
Lettuce Seeds ◽  
Lactuca Sativa L

Seed water content in relation to phytochrome-mediated germination of lettuce seeds (Lactuca sativa L. var. Grand Rapids)

1971 ◽  
Vol 49 (1) ◽  
pp. 111-115 ◽  
Author(s):  
A. I-Hsiung Hsiao ◽  
William Vidaver
Keyword(s):  
Water Content ◽  
Lactuca Sativa ◽  
Red Light ◽  
Second Stage ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Grand Rapids ◽  
Two Stages ◽  
Seed Water Content ◽  
Stimulation Of

It is possible to distinguish two stages in the influence of light on the germination of Lactuca sativa var. Grand Rapids (lettuce) seeds. The first stage, which is represented by the photoactivation or transformation of phytochrome, requires only a relatively low seed water content. Slightly higher seed water content is required for maximum far-red light repression, than for red light stimulation of germination. The second stage is indicated by the well-known situation in which previous red irradiations of the seeds can enhance germination but this takes place only with relatively high seed water content. Phototransformed phytochrome appears to persist and to be susceptible to photoreversal for at least 24 h after irradiation in the seeds with relatively low water content.

Activity of glucose-6-phosphate dehydrogenase from lettuce seeds (Lactuca sativa)

1974 ◽  
Vol 52 (10) ◽  
pp. 2225-2227 ◽  
Author(s):  
Henry L. Speer
Keyword(s):  
Enzyme Activity ◽  
Lactuca Sativa ◽  
Red Light ◽  
Supernatant Fraction ◽  
Lettuce Seed ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Glucose 6 Phosphate Dehydrogenase

The effects of phosphate, arsenate, arsenite, and sulfate on lettuce seed (Lactuca sativa L.) glucose-6-phosphate dehydrogenase were investigated. All four substances inhibited the enzyme and inhibition was substrate dependent. The reaction was specific for glucose-6-phosphate and NADP. No effect of red or far-red light could be observed on enzyme activity. All enzyme activity was confined to the supernatant fraction.

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.

scholarly journals Effect of landfill leachate on germination of lettuce seeds (Lactuca sativa L.)

2017 ◽  
Vol 21 ◽  
pp. 67
Author(s):  
Heider Alves Franco ◽  
Monica Regina da Costa Marques ◽  
Clarisse Ferreira Braga ◽  
Allana De Souza Izidorio ◽  
Sérgio Thode Filho
Keyword(s):  
Lactuca Sativa ◽  
Landfill Leachate ◽  
Lettuce Seeds ◽  
Lactuca Sativa L

The effects of ultra-high diluted gibberellic acid on in vitro lettuce seed germination.

2021 ◽  
Vol 15 (4) ◽  
pp. 50-54
Author(s):  
Carolina Santos Barreto ◽  
Fortune Homsani ◽  
Nina C Barboza Da Silva ◽  
Carla Holandino
Keyword(s):  
Gibberellic Acid ◽  
Lactuca Sativa ◽  
Germination Rate ◽  
Petri Dish ◽  
New Drugs ◽  
Lettuce Seed ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Petri Dishes

Lettuce seeds bioassays have been used in many different tests such as: alellopathyc models; developing of new drugs; ecotoxicity tests. In most cases, lettuce (Lactuca sativa L., Asteraceae) has been used because of its sensitivity, simultaneous and rapid germination, reliability of germination percentage and homogeneity of seeds. The main goal was to evaluate the effects of ultra-high diluted gibberellic acid (GA3) on lettuce seeds germination and seedling growth. Experiment was performed using Petri dishes containing one disk of Whatman nº01 paper watered with 1ml of water. In each Petri dish 10 lettuce seeds(Lactuca sativa L.) cv Regina 500 were placed and 2ml of the different treatment solutions were add: GA33µmol, GA3 3CH (10-6), GA3 12CH (10-24), water 12CH and water (no dilution and succussion). One milliliter solutions were added every 2 days of experiment. The experiment was repeated twice and each one consisted in 5 Petri dishes per treatment (n=100). All seeds were maintained in germination incubator under controlled temperature (25°C) and photoperiod (16L/8D). The tested substances were prepared according to Brazilian Homeopathic Pharmacopoeia (Brazil, 2011). The experiment was blinded all the time. All seeds germinated at same time (2 days) and after 7 days the germination rate was the same in all treatments. Root was affected just by Water 12 CH, in which shown the longest length (4.59 cm) when compared with others treatments. Shoot length was higher where gibberellin was added in concentration upper then Avogrado’s number.

The high reducing sugar content during germination contributes to desiccation damage in lettuce (Lactuca sativa L.) radicles

1995 ◽  
Vol 5 (3) ◽  
pp. 145-149 ◽  
Author(s):  
P. van der Toorn ◽  
B. D. McKersie
Keyword(s):  
Hydroxyl Radicals ◽  
Lactuca Sativa ◽  
Sugar Content ◽  
Primary Source ◽  
Reducing Sugar ◽  
Amino Groups ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Lipid Aldehydes

AbstractAt the time of protrusion, radicles of lettuce seeds became susceptible to desiccation damage. Concomitant with radicle elongation, both the reducing sugar content and the amount of lipid-aldehydes increased. The role of the hydroxy- and lipid-aldehydes in browning reactions that occurred during desiccation and re-imbibition was analysed. It was concluded that both types of aldehydes reacted with amino-groups during desiccation and that the increase in lipid-aldehydes during germination could be due to the augmented reducing sugar content. Therefore, the high reducing sugar content in radicles of germinated lettuce seeds may be the primary source of hydroxyl radicals, and thereby, a principal cause of desiccation damage.

scholarly journals The Impact of Light Spectrum and Intensity on the Growth, Physiology, and Antioxidant Activity of Lettuce (Lactuca sativa L.)

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2162
Author(s):  
Shiren J. Mohamed ◽  
Hail Z. Rihan ◽  
Naofel Aljafer ◽  
Michael P. Fuller
Keyword(s):  
Antioxidant Activity ◽  
Lactuca Sativa ◽  
Red Light ◽  
High Irradiance ◽  
Light Spectrum ◽  
Led Light ◽  
Growth Physiology ◽  
Lactuca Sativa L ◽  
Light Intensities ◽  
The Impact

This study focused on the physiology, growth and antioxidant activity response of hydroponically grown lettuce (Lactuca sativa L.) under sole-source LED lighting of differing spectra. Lighting spectra were provided by differing combinations of LEDs of three different peak wavelengths, (Blue 435, Blue 450, and Red 663 nm) with ratios of B450/R663: 1.25 ± 0.1, B450/R663: 1.25 ± 0.1, and B450/R663 1:1 at two light intensities of photosynthetically active radiation (PAR) (270 μmol m−2 s−1 and 60 μmol m−2 s−1). A further experiment was conducted, in which Blue and Red LEDs were supplemented with Green (Blue 450, Red 663, and Green 520 nm) with ratios of B435/R663: 1.25 ± 0.1, B450/R663/G520: 1/0.73/0.26, and B450/R663: 1.25 ± 0.1. LED light intensities under the different spectra were adjusted to deliver the same level of PAR (270 ± 20 μmol m−2 s−1). Results from the first experiment showed that increased fraction of blue 435 nm in combination with red light at 663 nm at high irradiance enhanced the physiology of lettuce (i.e., significantly increased assimilation rate, stomatal conductance and transpiration rate) and increased the yield while having no significant effect on antioxidant activity. At the lower irradiance, the B435/R663 significantly increased antioxidant activity compared to other spectra. Results from the second experiment showed no significant effect of the spectra of LEDs on the physiology and yield of lettuce, but antioxidant activity was very significantly induced by B450/R663 at the ratio of 1.25 ± 0.1. However, the amount was still less than that obtained by B435/R663 1.25 ± 0.1 from the first experiment. This study indicates that LED light with a spectrum of B435/R663 at a ratio of 1.25 ± 0.1 significantly improves lettuce yield and antioxidant activity.

scholarly journals Fitoquímica e Alelopatia da Aroeira -Vermelha (Schinus terebinthifolius Raddi) na Germinação de Sementes

2021 ◽  
Vol 25 (1) ◽  
pp. 02-08
Author(s):  
Gislayne de Araujo Bitencourt ◽  
Cibele Caren Moraes Gonçalves ◽  
Artur Guerra Rosa ◽  
Deizeluci De Fátima Pereira Zanella ◽  
Rosemary Matias
Keyword(s):  
Lactuca Sativa ◽  
Color Change ◽  
Eucalyptus Camaldulensis ◽  
Allelopathic Effect ◽  
Alcoholic Extract ◽  
Schinus Terebinthifolius ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Randomized Design ◽  
Germination And Growth

Os compostos alelopáticos podem afetar o crescimento e inibir a germinação das espécies. O objetivo deste trabalho foi analisar a fitoquímica e o efeito alelopático do extrato das folhas de Schinus terebinthifolius Raddi na germinação e crescimento de plântulas de Lactuca sativa L. e, posteriormente, aplicar a metodologia em eucalipto vermelho (Eucalyptus camaldulensis). Os compostos químicos foram determinados em extrato alcoólico das folhas, comparados e contrastados observando a alteração de cor. As sementes de alface e eucalipto vermelho foram distribuídas em gerbox contendo papel filtro como substrato, umedecido com 7 mL do extrato aquoso das folhas frescas, nas seguintes concen trações: (0; 12,5; 25; 50; 75 e 100%). Para todas as análises e experimentos foram utilizados três repetições. Os gerbox foram distribuídos em um delineamento inteiramente casualizado, mantidos em câmara de germinação com temperatura de 20 °C para alface e 28°C para eucalipto e fotoperíodo de 12 horas. Durante o segundo e quinto dia foram realizadas contagens das sementes germinadas de alface. O período de avaliação do experimento foi de cinco dias para alface e 12 dias para eucalipto. Ao final, foram determinadas as porcentagens de germinação, comprimento da raiz e de parte aérea das plântulas. Os resultados demonstraram interferência negativa na germinação e crescimento de alface e eucalipto em função do aumento da concentração do extrato. Entre os aleloquímicos predominantes estão os compostos fenólicos e derivados, com destaque aos flavonoides, terpenos e heterosídeos cardioativos o que pode estar relacionados ao efeito alelopático negativo da aroeira. O uso da aroeira associado ao eucalipto deve ser feito com um manejo adequado.   Palavras-chave: Alface. Aleloquímicos. Anacardiaceae. Eucalipto. Efeito Alelopático.   Abstract Allelopathic compounds can affect growth and inhibit species germination. The objective of this work was to analyze the phytochemistry and the allelopathic effect of  extract of  Schinus terebinthifolius Raddi leaves on the  Lactuca sativa L. seedlings germination and growth and later apply the methodology in red eucalyptus (Eucalyptus camaldulensis). The chemical compounds were determined in the leaves alcoholic extract, compared and contrasted observing the color change. The lettuce and red eucalyptus seeds were distributed in a gearbox containing filter paper as a substrate, moistened with 7 mL of the fresh leaves aqueous extract in the following concentrations: (0; 12.5; 25; 50; 75 and 100%). For all analyzes and experiments, three repetitions were used. The gearbox was distributed in a completely randomized design, maintained in a germination chamber with a temperature of 20 °C for lettuce and 28 °C for eucalyptus and a photoperiod of 12 hours. Germinated lettuce seeds were counted during the second and fifth days. The experiment evaluation period was five days for lettuce and 12 days for eucalyptus. At the end, the germination percentages, root length and the seedlings aerial part were determined. The results showed negative interference in the germination and growth of lettuce and eucalyptus due to the extract increased concentration. The most frequent allelochemicals were flavonoids, terpenes, tannins, anthocyanins and heterosides, which are probably related to the negative allelopathic effect. The use of  aroeira associated with eucalyptus must be done with proper management.   Keywords: Lettuce, Allelochemicals Anacardiaceae. Eucalyptus. Allelopathic Effect.

scholarly journals DEVELOPMENT OF ELEMENTS OF TECHNOLOGY FOR PLANTING MATERIAL OF LETTUCE (LACTUCA SATIVA L.) ON VIRUS-FREE BASIS USING METHODS OF BIOTECHNOLOGY

2019 ◽  
pp. 22-26 ◽  
Author(s):  
O. B. Romanova ◽  
A. V. Soldatenko ◽  
O. A. Chichvarina ◽  
V. A. Akhramenko ◽  
O. V. Pavlova ◽  
...  
Keyword(s):  
Lactuca Sativa ◽  
Nutrient Medium ◽  
Culture Media ◽  
Time Interval ◽  
Planting Material ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Different Temperatures

The article presents the results of research on the production in vitro of regenerated plants from the seeds of cultivars of lettuce (Lactuca sativa L.) Emerald, Bouquet, Chameleon (FSBSI Federal Scientific Vegetable Center), susceptible of aspermia tomato (Tomato aspermy cucumovirus) – AsTV. Seeds of strongly susceptible to AsTV varieties of salad Chameleon and Bouquet were subjected to thermotherapy at different temperatures (37°C, 38°C, 40°C) for a different time interval (1, 3, 5, 7, 10 days) in dry form and when moistened. Marked varietal specificity during germination of seeds after thermotherapy. Thus, the greatest number of seedlings in the emerald variety was obtained after 5 days of thermotherapy (10.0±0), while the Bouquet variety had the best results after 3 days of thermotherapy (9.3±1.2) with moisture. After thermotherapy of dry seeds by 40°C plant material of cultivar Emerald was planted on solid and liquid culture media. The conditions of step sterilization of lettuce seeds for introduction into the culture in vitro were chosen: washing in 96% ethanol, then in 50% aqueous solution of "Whiteness" with the addition of Twin-20, after in sterile distilled water. The nutrient medium for germination of lettuce seeds was used: Gamborg B5 (2% sucrose, 7.0 g/l agar), and the liquid nutrient medium was of that composition. The obtained seedlings were cutted and transferred to medium MS (2% sucrose, 0.1 mg/l ha and 1 mg/l BAP, 3.0 g/l phytogel). The formed shoots for rooting were transferred to the MS medium (2% sucrose, 3.0 g/l phytogel). In the future, lettuce plants will be adapted in vivo and tested for the presence of tomato aspermia virus in the planting material.

Sign in / Sign up

Export Citation Format

Share Document