| 释义 |
periclinal, a. (n.)|pɛrɪˈklaɪnəl|
[f. Gr. περικλῑν-ής (see next) + -al1: cf. anticlinal.]
1. Geol. Sloping in all directions from a central point: = quaquaversal.
1876Page Adv. Text-bk. Geol. iv. 84 They are found in dome-shaped positions, and sloping on every side from a common centre or apex, and then they are said to be periclinal, cycloclinal, or quaquaversal. 1881Johnston in Pop. Sci. Monthly XIX. 53 The subjacent rock would thus have a quaquaversal or periclinal dip away on all sides.
2. a. Bot. [= Ger. perikline (Sachs 1878).] Applied to those cell-walls at a growing-point which run in the same direction as the circumference of the shoot. More widely, occupying or occurring in a layer parallel to the surface of an organ. Also as n. = periclinal wall or plane.
1882Vines Sachs' Bot. 951 The planes of the walls in a growing-point are classified thus: a. Periclinal, those which are curved in the same direction as the surface (seen in longitudinal section). b. Anticlinal... c. Radial... d. Transverse. Ibid., If the outline (in longitudinal section) of the growing-point is a parabola, the periclinals will constitute a system of confocal parabolas of different parameter. 1885G. L. Goodale Physiol. Bot. (1892) 382. 1965 Bell & Coombe tr. Strasburger's Textbk. Bot. 69 (caption) Each segment becomes divided by a periclinal wall..into an inner and an outer (cortical) cell. 1965K. Esau Plant Anat. (ed. 2) iv. 76 The lateral meristems are particularly distinguished by divisions parallel with the nearest surface of the organ (periclinal divisions). 1975M. E. McCully in Torrey & Clarkson Devel. & Function of Roots vi. 111 The daughter cells of these periclinal divisions lack the intense basophilia of the parent epidermal cells.
b. Applied to a type of chimæra (see quot. 1968). Also as n., a periclinal chimæra. [ad. G. periklinalchimäre (E. Baur 1909, in Zeitschr. f. induktive Abstammungs- u. Vererbungslehre I. 344).]
1916Jrnl. Genetics VI. 78 Proof that a plant is a periclinal chimaera may..be obtained from adventitious buds arising in internodes of the stem, as well as from those formed on roots. 1925Ibid. XVI. 44 Simple white-over-green periclinals would presumably..give only white seedlings. 1959New Biol. XXX. 39 In periclinal chimeras there is often great variation in the pigment distribution pattern. 1963Heredity XVIII. 270 The striped varieties of Commelina, Tradescantia and Zebrina have also been shown to be periclinal chimeras with a rather specialised development. 1968R. Rieger et al. Gloss. Genetics & Cytogenetics 59 Chimeras..in plants may be classified..according to their structure into a) sectorial (different tissues grow side by side and occupy distinct sectors of varying size), b) periclinal (different tissues are disposed one with the other..), c) mericlinal (actually an interrupted periclinal..).
Hence periˈclinally adv., (a) with a dip on all sides from a central point; (b) Bot., in the manner of a periclinal division or chimæra.
1890in Cent. Dict. 1916Jrnl. Genetics VI. 79 Plants in which the variegation affected the skin periclinally. 1963Heredity XVIII. 281, LI which does not divide periclinally in the apex may do so frequently during leaf development. 1975M. E. McCully in Torrey & Clarkson Devel. & Function of Roots vi. 111 When the young primordium is about one-third of the way across the cortex a few epidermal cells at its tip divide periclinally and thus produce the root cap initials. |