scholarly journals Role of Ethylene in Lactuca sativa cv `Grand Rapids' Seed Germination

1986 ◽  
Vol 81 (3) ◽  
pp. 780-787 ◽  
Author(s):  
Fred B. Abeles
Keyword(s):  
Seed Germination ◽  
Lactuca Sativa ◽  
Grand Rapids

scholarly journals Potencial Alelopático de Espécies da Família Fabaceae Lindl

2020 ◽  
Vol 24 (1) ◽  
pp. 65-74
Author(s):  
Ykaro Richard Oliveira ◽  
Paulo Henrique da Silva ◽  
Maria Carolina de Abreu ◽  
Cledinaldo Borges Leal ◽  
Lauana Pereira de Oliveira
Keyword(s):  
Chemical Composition ◽  
Seed Germination ◽  
Weed Control ◽  
Lactuca Sativa ◽  
Allelopathic Effect ◽  
Ecological Role ◽  
Natural Conditions ◽  
Allelopathic Effects ◽  
Laboratory Bioassays

O objetivo deste artigo foi realizar uma pesquisa de caráter bibliográfico acerca dos estudos desenvolvidos com representantes da família Fabaceae e destacar quais efeitos alelopáticos tais espécies desempenharam sobre outras plantas. Foram listadas 24 espécies de Fabaceae, sendo o gênero Anadenanthera o mais representativo neste artigo, com três espécies estudadas. A partir da análise dos arquivos, foi evidenciado que os representantes da família Fabaceae investigados apresentam em sua composição química substâncias responsáveis por gerar um efeito alelopático sobre outras espécies, caracterizando, dessa forma, uma função ecológica desses vegetais para a constituição dos ecossistemas em que se incluem. Além disso, tal característica pode despontar uma provável utilização desses seres no controle de plantas daninhas, que representam um grande problema para os agricultores. Também foram percebidos com maior frequência estudos voltados ao uso de bioensaios laboratoriais com o uso da espécie Lactuca sativa, noticiando a carência de estudos mais complexos sobre a ação dos aleloquímicos, quando lançados em condições naturais no ambiente.   Palavras-chave: Aleloquímicos. Germinação de Sementes. Leguminosae.   Abstract The objective of this paper was to perform a bibliographic research about the studies carried out with representatives of the Fabaceae family and stress out what  allelopathic effects such species develop on other plants. Twenty-four Fabaceae species were listed, being the Anadenanthera genus the most representative in this article, with three species studied. It was noticed in the studies analysis that certain Fabaceae species contain  in their chemical composition, substances responsible for an allelopathic effect on other species, characterizing an ecological role of these plants for the  ecosystems establishment. This feature can suggest the use of these species in weed control, which represent a problem to farmers. It was seen more often studies focused on the use of laboratory bioassays with Lactuca sativa, reporting the lack of more complex studies on the action of allelochemicals when launched in natural conditions in the environment. Keywords: Allelochemicals. Seed Germination. Leguminosae.

The fine structure of the embryo of Lactuca sativa. II. Changes during germination

1968 ◽  
Vol 46 (11) ◽  
pp. 1447-1453 ◽  
Author(s):  
Lalit M. Srivastava ◽  
Ronald E. Paulson
Keyword(s):  
Fine Structure ◽  
Seed Germination ◽  
Lactuca Sativa ◽  
Root Tip ◽  
Membrane Systems ◽  
Lactuca Sativa L ◽  
Progressive Loss ◽  
Grand Rapids ◽  
Developmental Continuity ◽  
Embryo Cells

Changes in fine structure and reserve materials of the dormant embryos of Lactuca sativa L. var. Grand Rapids were studied during the first 4 days of germination. Activation of cells begins soon after the embryos are soaked and involves a progressive loss of reserve materials, an increased clarity of organelles and membrane systems, and development of structures either absent or present in a highly modified state in the dormant embryo. Cells of the hypocotyl just behind the root tip are first activated. Activation then progresses through the hypocotyl and acropetally in the cotyledons. These results are discussed in relation to physiology of seed germination. Plastids show several patterns of development, depending on the tissues in which they are localized. There is developmental continuity between the dissolution of protein bodies and formation of vacuoles.

Characterization of SAN 9789-Stimulated Lettuce (Lactuca sativa) Seed Germination

Weed Science ◽  
1985 ◽  
Vol 33 (2) ◽  
pp. 160-164 ◽  
Author(s):  
Karl-Olof Widell ◽  
Christer Sundqvist ◽  
Hemming I. Virgin
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Lactuca Sativa ◽  
Red Light ◽  
Inhibitory Effect ◽  
Lettuce Seeds ◽  
Grand Rapids ◽  
Minor Degree ◽  
A Minor

Dark germination of light-requiring lettuce seeds (Lactuca sativaL. ‘Grand Rapids’) was stimulated by SAN 9789 [4-chloro-5-(methylamino-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone] and to a minor degree by BASF 13761 [4-chloro-5-methoxy-2-phenyl-3(2H)-pyridazinone] and BASF 44521 [4-chloro-5-methoxy-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone], but not by’ pyrazon [5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone], SAN 9785 [4-chloro-5-(dimethylamino)-2-phenyl-3 (2H)-pyridazinone], SAN 9774 [5-amino-4-chloro-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone], or SAN 6706 [4-chloro-5-(dimethylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone]. SAN 9789 stimulation was inhibited by cis-4-cyclohexene-1,2-dicarboximide (CHDC), and abscisic acid (ABA) at 1 × 10-4M. Red light nullified the inhibitory effect of CHDC (1 × 10-4M) but not the inhibitory effect of ABA (1 × 10-4M) on SAN 9789 stimulated germination. Gibberellic acid (GA3) and kinetin (6-furfurylaminopurine) increased the germination stimulatory effect of SAN 9789 in darkness. Temperatures above 25 C decreased the effect of SAN 9789, with a temperature of 35 C completely inhibiting germination. The inhibitory effect of CHDC was strongly decreased at temperatures below 20 C. SAN 9789-induced germination in darkness was always the same (25 to 26% units increase in germination) even though the red light-stimulated germination differed with the seed batch.

s-Triazine Effects on Seed Germination and Hypocotyl Hook Opening

Weed Science ◽  
1973 ◽  
Vol 21 (5) ◽  
pp. 461-464 ◽  
Author(s):  
C. G. P. Pillai ◽  
D. E. Davis
Keyword(s):  
Seed Germination ◽  
Gossypium Hirsutum ◽  
Lactuca Sativa ◽  
Red Light ◽  
Lettuce Seed ◽  
Grand Rapids

The effects of sevens-triazines on the opening of the hypocotyl hook of cotton (Gossypium hirsutumL. ‘DPL Smooth Leaf’) and the germination of lettuce seed (Lactuca sativaL. ‘Grand Rapids’) were investigated. Thes-triazines used were ametryne [2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine], atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], cyprazine [2-chloro-4-(cyclopropylamino)-6-(isopropylamino)-s-triazine], prometone [2,4-bis (isopropylamino)-6-methoxy-s-triazine], prometryne [2,4-bis (isopropylamino)-6-(methylthio)-s-triazine], propazine [2-chloro-4,6-bis(isopropylamino)-s-triazine], and simazine [2-chloro-4,6-bis(ethylamino)-s-triazine]. All triazines except cyprazine stimulated germination of lettuce seed given 4 min of dim red light but none were stimulatory in the dark. Maximum stimulation occurred with 1 X 10-8to 1 X 10-12Ms-triazine. All triazines except atrazine and cyprazine stimulated the opening of cotton hypocotyl hooks given 2 hr of dim red light of thes-triazines tested. Prometryne and ametryne were the most stimulatory to hook opening in the light and the most inhibitory in the dark. Their effects paralleled those of kinetin.

scholarly journals Role of Smoke Stimulatory and Inhibitory Biomolecules in Phytochrome-Regulated Seed Germination of Lactuca sativa

2019 ◽  
Vol 181 (2) ◽  
pp. 458-470 ◽  
Author(s):  
Shubhpriya Gupta ◽  
Lenka Plačková ◽  
Manoj G. Kulkarni ◽  
Karel Doležal ◽  
Johannes Van Staden
Keyword(s):  
Seed Germination ◽  
Lactuca Sativa
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