O dimorfismo dos ramos em Coffea arabica L.

Carvalho, Ana Maria; Krug, C. A.; Mendes, J. E. T.

doi:10.1590/s0006-87051950000600001

Cited by 7 publications

(4 citation statements)

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“…Carvalho, Krug, and Mendes (1950) report a similar behavior in Coffea. There are many other examples of such topophysis (p. 212).The differentiation of particular organs-root, stem, leaf, flowerduring development is markedly influenced by growth substances of various…”

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confidence: 53%

Plant morphogenesis

Sinnott¹

1960

255

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Biological organization is to be seen most distinctly in bodily development. It is obvious that, to produce an individual with a specific form and structure, growth must be more rapid in some directions than in others and must form tissues and organs of different character in different places. Embryology has shown how precisely the activities in one part of the developing individual are related to those in every other part. Few happenings in nature are as fascinating to watch as the unfolding and morphology. More commonly and properly, however, it includes, in addition to a discussion of purely descriptive facts as to the origin of form, a study of the results of experimentally controlled development and an analysis of the effects of the various factors, external and internal, that determine how the development of form proceeds. In other words, it attempts to get at the underlying formativeness in the development of organisms and especially to reach an understanding of the basic fact of which form is the most obvious manifestation-biological organization Workers with plants have a number of advantages, however. In plants, permanently embryonic regions, the meristems, are available for study. At the tip of shoot and root and in the cambial layers these are indeterminate and produce new plant structures almost indefinitely. Such meristems are usually numerous or extensive on the same plant so that ample material for the study of development, identical in genetic constitution, is available. Growth and differentiation in the development of a plant are thus continuing processes and not limited to a single and often brief life cycle.Organs such as leaves, flowers, and fruits, which are determinate in growth, pass through a cycle closely comparable to that of individual animals, and morphogenetic problems can also often profitably be studied in them. The fact that they are usually produced in abundance on a single plant is a further advantage, for here the investigator need not be concerned about genetic diversity in his material but can study strictly The Cellular Basis of Growth 33 structures such as tubers and fruits, the greater size is due to an increase in both the number and the size of their cells. Lehmann (1926) found a positive correlation between the size of a potato tuber and that of its cells. Since the increase in cell size was by no means proportional to that in tuber size, it was evident that large tubers have more as well as larger cells. The same relations are found in tomatoes (Houghtaling, 1935). A more detailed study of this problem, in large-fruited and small-fruited races of gourds, was made by Sinnott (1939; Fig. 3-4). Here cell size increases in the young ovary but much less rapidly than organ size, showing that cell division is taking place. During this period there is more increase in cell size in the larger races. The size at which the cells divide steadily increases. At about the time of flowering, however, division in most of the young fruit ceases, first in the central region and then prog...

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confidence: 53%

Plant morphogenesis

Sinnott¹

1960

255

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“…Parmi de nombreux exemples, on peut citer Coffea arabica L. (Carvalho et coll., 1950) certains Phyllantus, Euphorbiacées tropicales particulièrement analysées sous cet aspect (Bancilhon, 1969). Ces plantes sont constituées ( Fig.…”

Section: -Expression De Potentialités Morphogénétiques Végétatives unclassified

Réflexions sur les problèmes de rajeunissement chez les végétaux

Nozeran

Ducreux

Rossignol-Bancilhon

1982

Bulletin de la Société Botanique de France. Lettres Botaniques

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Résumé.-Les concepts de sénescence et de rajeunissement chez le végétal sont discutés en fonction de l'évolution morphogénétique caractérisant son cycle de développement. Une analyse, s'appuyant sur des observations concernant l'ensemble du monde végétal, montre que le phénomène de vieillissement peut-être l'objet, à différents niveaux, de discontinuités ménageant, sous le contrôle des conditions écologiques, des processus rajeunissants y compris indépendamment des phénomènes de reproduction sexuée.En s'appuyant sur les caractéristiques manifestées par les plantes développées in vitro, le rô-le de l'environnement (externe et interne) d'un méristème, les modalités connues du fonctionnement de l'information héréditaire, on a tenté de dégager une approche du déterminisme de l'installation (ou de la ré acquisition) chez une partie de la plante du type de fonctionnement juvénile.Summary.-The concepts of plant senescence and rejuvenation are discussed as a function of the morphogenetic evolution characterising its growth cycle. The analysis of observations over the whole of the plant domain shows that the phenomenon of senescence is subject to discontinuities at various levels ; the latter, subject to ecological conqitions, allows rejuvenation processes, including or not the phenomena of sexual reproduction to occur.An approach is presented on the determination of the on set (or reacquisition) of the juvenile behaviour in part of a plant based on characteristics manifested in plants developed in dtro. the role of the environment (external and internai) of a meristem and the known modalities of the functioning of genetic material.

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“…Como já se mencionou em estudo anterior (1), em certas espécies vegetais, pertencentes aos gêneros Araucária, Hedera, Theóbroma, Cojjea e outros, observa-se um dimorfismo dos ramos, os quais tomam direções diferentes durante o desenvolvimento.…”

Section: -Dimorfismo Dos Ramos Em Caféunclassified

Genética de Coffea: XIII - Hereditariedade do caraterístico erecta em Coffea arabica L.

Carvalho¹,

Krug

1950

Bragantia

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In the present paper the authors present the results of a genetic study concerning the erecta type of growth of the lateral branches of Coffea arabica L. The erecta mutant, which probably originated in Java, differs from normal coffee plants by having upright growing lateral branches instead of plagiotropic ones. However, in spite of the fact that both, the main shoot and the lateral branches grow in the same direction, the dimorphic nature of the branches still persists. The genetic studies carried out since 1933, which included the study of progenies of F1, F2 generations and backcrosses, have revealed that the erecta character is conditioned by one pair of dominant genes Er Er. It is not yet known whether all erecta plants, of different origins, have the same dominant gene, but investigations already in progress are expected to yield information on this matter. Of all genes so far studied in C. arabica, Er is the most completely dominant, the heterozygote being indistinguishable from the homozygote. The erecta gene has been found to show complete penetrance and a constant expressivity

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O dimorfismo dos ramos em Coffea arabica L.

Cited by 7 publications

References 1 publication

Plant morphogenesis

Plant morphogenesis

Réflexions sur les problèmes de rajeunissement chez les végétaux

Genética de Coffea: XIII - Hereditariedade do caraterístico erecta em Coffea arabica L.

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