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CYTOHISTOLOGICAL STUDIES OF CYTOCHIMERIC AND TETRAPLOID GRAPES
Author(s) -
Thompson Maxine M.,
Olmo H. P.
Publication year - 1963
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1963.tb06569.x
Subject(s) - tunica , biology , botany , chromosome , chromosome number , shoot , apex (geometry) , genetics , karyotype , gene
Thompson, M. M., and H. P. Olmo. (U. California, Davis.) Cytohistological studies of cytochimeric and tetraploid grapes. Amer. Jour. Bot. 50(9): 901–906. Illus. 1963.—Cytohistological studies were made on 62 different grape clones suspected to be tetraploids to determine if they were chimeras, and if so, what type. The chromosomal constitution of the apical layers in the shoot was determined on the basis of cell and nucleus size, size of chromosome mass, and chromosome estimates or counts. Three cytological types were observed; 2–4, 2 4–2, and 4–4. The possible types of chimeras and their stability depend upon the organization of the shoot apex. In most buds there appeared to be a biseriate tunica covering a corpus. However, the number of tunica layers fluctuated from 1 to 3, and there were occasional periclinal divisions in L‐II. This lack of discreteness of the second layer probably accounts for the homogeneity of all tissue beneath the superficial layer. The rarity of periclinal divisions in L‐I explains the stability of 2–4 types, but reversions are not impossible. The relative frequency of the different types of sports is discussed in relation to their possible origin. The theory of intraclonal variability developed in grapes by Reichardt (1955) and Rives (1961) on the basis of a multilayered shoot apex is re‐evaluated under the concept of a functionally uniseriate tunica.