The Shoot Apex in Pteridophytes

Wardlaw, C. W.

doi:10.1111/j.1469-185x.1945.tb00444.x

Cited by 13 publications

(4 citation statements)

References 43 publications

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“…These range from 9 to 21 and are in general agreement with the shape of cells in other undifferentiated tissues. For a statement of conditions in the apical meristem of the shoot in ferns the reader is referred to Wardlaw (1945). This author has also published an extensive series of papers on experimental and analytical studies of pteridophytes, many of which are cited in his books (1952«, 1952&) and in later papers by himself and his colleagues.…”

Section: Growthmentioning

confidence: 99%

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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Section: Growthmentioning

confidence: 99%

Plant morphogenesis

Sinnott¹

1960

255

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“…RECENT WORKERS (Camp, 1943;Maheshwari, 1945;Bailey, 1949) have suggested that taxonomic relationships be based upon a study of the plant from all fields of plant science. In addition to possible taxonomic considerations, comparative morphology should provide more basic facts concerning the development of the shoot apex since, as Wardlaw (1945) points out, it is the "seat of all primary formative activities." As a means toward these ends, this study compares the structure and development of the shoot apex and its derivatives in a large group of related plants.…”

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confidence: 99%

“…Summaries of the literature concerned with the shoot apex up to the present time can be found in the comprehensive reviews by Foster (1939Foster ( , 1941Foster ( , 1949, Engard (1944), Sifton (1944), Wardlaw (1945), Reeve (1948), and Philipson (1947Philipson ( , 1949 .…”

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confidence: 99%

A Comparative Study of Vegetative Shoot Apices in the Rosaceae

Rouffa

Gunckel

1951

American J of Botany

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“…This continuous acropetal differentiation of the procambium has been noted by many authors since the work of Esau (1942Esau ( , 1943. Exceptions to this pattern of development should be noted, as indicated by the recent work of Ball (1949) , Wardlaw (1945), and the Snows (1931,1933) where the initial procambial development is described as basipetal. Probably either pattern is possible as Hegediis (1949) has demonstrated.…”

mentioning

confidence: 93%