Hilgardia
Hilgardia
Hilgardia
University of California
Hilgardia

Vascular differentiation in the pear root

Author

Katherine Esau

Author Affiliations

Katherine Esau was Assistant Professor of Botany and Assistant Botanist in the Experiment Station.

Publication Information

Hilgardia 15(3):299-324. DOI:10.3733/hilg.v15n03p299. April 1943.

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Abstract

Abstract does not appear. First page follows.

Introduction

The present paper deals with the development of the root of Pyrus communis L., with special attention to the vascular tissues. Though considerable information is available on root structure of herbaceous plants (Hayward, 1938); (Esau, 1940),3 only one rather complete account of tissue differentiation in a root of a woody species appears to exist in modern botanical literature (Hayward and Long, 1942). The need for such accounts in the teaching of plant anatomy, especially in agricultural institutions, is obvious.

The present problem was selected also because of the writer’s interest in the differentiation of the phloem tissue in different organs of seed plants. Since many studies have been made on the phloem of roots of herbaceous plants (review by Esau, 1943), it seemed timely to add some data on the ontogeny of this tissue in a woody root.

Materials and Methods

The root material used in preparing the permanent slides and the photomicrographs was obtained from trees grown in a culture solution by the Plant Nutrition division at Berkeley. The material was killed in a formalin-acetic-alcohol fixing fluid and imbedded in paraffin after ordinary dehydration and clearing in mixtures of ethyl alcohol and xylene.

The roots grown in the culture solution were compared with soil grown roots from young trees 5 to 6 inches high grown from seeds of the Winter Nelis variety. The latter roots were examined in free-hand sections.

Literature Cited

Barghoorn Elso S. Jr. The ontogenetic development and phylogenetic specialization of rays in the xylem of dicotyledons. I. The primitive ray structure. Amer. Jour. Bot. 1940. 27(10):918-28. DOI: 10.2307/2436561 [CrossRef]

Esau K. Initial localization and subsequent spread of curly-top symptoms in the sugar beet. Hilgardia. 1935. 9(8):397-436. DOI: 10.3733/hilg.v09n08p395 [CrossRef]

Esau K. Ontogeny and structure of the phoem of tobacco. Hilgardia. 1938. 11(8):343-424. DOI: 10.3733/hilg.v11n08p343 [CrossRef]

Esau K. Development and structure of the phloem tissue. Bot. Rev. 1939. 5:373-432. DOI: 10.1007/BF02878295 [CrossRef]

Esau K. Developmental anatomy of the fleshy storage organ of Daucus carota. Hilgardia. 1940. 13(5):175-226. DOI: 10.3733/hilg.v13n05p175 [CrossRef]

Esau K. Phloem anatomy of tobacco affected with curly top and mosaic. Hilgardia. 1941. 13(8):437-90. DOI: 10.3733/hilg.v13n08p435 [CrossRef]

Esau K. Origin and development of primary vascular tissues in seed plants. Bot. Rev. 1943. 9:125-206. DOI: 10.1007/BF02872466 [CrossRef]

Foster A. S. Practical plant anatomy. 1942. New York, N. Y.: D. Van Nostrand Company, Inc. 155p.

Guttenberg H. von, Linsbauer K. Der primäre Bau der Angiospermenwurzel. Handbuch der Pflanzenanatomie 2. Abt. 3. Teil: Samenpflanzen. 1940. VIII: Berlin: Gebrüder Borntraeger. 369p. Lief. 39

Hayward H. The structure of economic plants. 1938. New York, N. Y.: The Macmillan Co. 674p.

Hayward H., Long E. M. The anatomy of the seedling and roots of the Valencia Orange. U. S. Dept. Agr. Tech. Bul. 1942. 786:1-31.

Lloyd F. E. Guayule (Parthenium argentatum Gray), a rubber plant of the Chihuahuan desert. Carnegie Inst. Wash. Pub. 1911. 139:1-213.

Russow E. Betrachtungen über das Leitbündel-und Grundgewebe aus vergleichend morphologischem und phylogenetischem Gesichtspunkt 1875. p.78. Schnakenburg’s Anstalt, Dorpat

Schüepp Otto, Linsbauer K. Meristeme. Handbuch der Pflanzenanatomie 1. Abt. 2. Teil: Histologie. 1926. IV: Berlin: Gebrüder Borntraeger. 114p. Lief. 16

Smith G. F., Kersten H. The relation between xylem thickenings in primary roots of Vicia faba seedlings and elongation, as shown by soft X-ray irradiation. Torrey Bot. Club Bul. 1942. 69:221-34. DOI: 10.2307/2481657 [CrossRef]

Esau K. 1943. Vascular differentiation in the pear root. Hilgardia 15(3):299-324. DOI:10.3733/hilg.v15n03p299
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