The fine structure of the embryo of Lactuca sativa. I. Dry embryo

1968 ◽  
Vol 46 (11) ◽  
pp. 1437-1445 ◽  
Author(s):  
Ronald E. Paulson ◽  
Lalit M. Srivastava
Keyword(s):  
Lactuca Sativa ◽  
Osmium Tetroxide ◽  
Light And Electron Microscopy ◽  
Membrane Systems ◽  
Cortical Cells ◽  
Mesophyll Cells ◽  
Lactuca Sativa L ◽  
Processed Material ◽  
Grand Rapids ◽  
Definition Of

Dry embryos of Lactuca sativa L. var. Grand Rapids were studied by improved techniques of light and electron microscopy. Cells of the dry embryo are filled with reserve proteins and lipids; the latter are preserved in the processed material only if the material is fixed in osmium tetroxide at some stage before dehydration and embedment. Nuclei, mitochondria, ribosomes, and some membranes show the least modifications in the dry state; other organelles are poorly defined and some may be absent. The best definition of organelles and membrane systems is found in the root apical cells, least in the cortical cells of the hypocotyl and mesophyll cells of the cotyledons.

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.

scholarly journals Penggunaan AB Mix dan Media Tanam terhadap Viabilitas Tanaman Selada (Lactuca sativa L. Var. New Grand Rapids) dalam Hydroponic Wick System

2020 ◽  
Vol 5 (1) ◽  
pp. 14-19
Author(s):  
Imam Safir Alwan Nurza ◽  
Diliviva Venesia
Keyword(s):  
Lactuca Sativa ◽  
Agricultural Sector ◽  
Growth And Yield ◽  
Lactuca Sativa L ◽  
Data Collection And Analysis ◽  
Grand Rapids ◽  
Wet Weight ◽  
Number Of Leaves ◽  
Resource Wealth ◽  
Natural Resource Wealth

Indonesia is a country that has abundant natural resources. One of the natural resource wealth is in the agricultural sector. The agricultural sector has a variety of agricultural commodities found in Indonesia. One of them is horticulture. Lettuce (Lactuca sativa L.) is a horticultural commodity. The purpose of this study was to determine the use of ab mix and planting media on lettuce (Lactuca sativa L. var New Grand Rapids) in increasing growth and yield after 40 Days After Planting (HST). This research method is an experiment with statistical data collection and analysis techniques. The results of this study are the number of leaves, plant height, and wet weight in the ab mix is ​​higher than aquades (control) because the ab mix provides nutrients for plant growth so that the plant becomes tall and enlarged with its leaves looking wide. However, the number of seeds germinated and plant viability in aquades (control) was higher than ab mix because there was an inorganic salt in ab mix that inhibited seed germination so that the seed membrane in absorbing water became impermeable.

scholarly journals Seleção de genótipos de Lactuca sativa L. para a produção com adubação orgânica

Revista CERES ◽  
2011 ◽  
Vol 58 (2) ◽  
pp. 202-207 ◽  
Author(s):  
Marcelo de Almeida Guimarães ◽  
Marcelo Storni Mandelli ◽  
Derly José Henriques da Silva
Keyword(s):  
Lactuca Sativa ◽  
Lactuca Sativa L ◽  
Grand Rapids

Com o objetivo de avaliar diferentes genótipos de alface (Lactuca sativa L.), quanto à adaptação a adubação orgânica, foram testados 18 acessos, pertencentes ao Banco de Germoplasma de Hortaliças da Universidade Federal de Viçosa (BGH - UFV) e comparado o desempenho destes com dois cultivares comerciais: Regina de Verão e Crespa Grand Rapids. O experimento foi conduzido com três repetições, em casa de vegetação, e os genótipos foram comparados em substratos contendo adubação mineral e adubação orgânica. As plantas foram cultivadas em vasos de polietileno, com capacidade para 3 dm³, preenchidos com 2,5 dm³ de substrato. O substrato contendo adubação mineral foi preparado a partir do solo, comumente cultivado, e adubado, segundo as recomendações convencionais para a cultura da alface, a partir da análise de rotina do solo. O substrato contendo adubação orgânica consistiu em solo, manejado organicamente, e adubado com 50 t ha-1 de composto orgânico. Na colheita, foram avaliadas as características morfológicas das plantas e a massa fresca e seca das folhas. Observou-se grande diversidade de formas, tamanhos e coloração, entre os acessos, sendo que os acessos BGH 2625, BGH 118 e o cultivar Regina de Verão apresentaram características qualitativas e produtividade que os selecionam para serem utilizados em programas de melhoramento, visando à produção de cultivares para ambiente com adubação orgânica.

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