Premium
EFFECT OF THE CALYPTRA ON INTERCALARY MERISTEMATIC ACTIVITY IN THE SPOROPHYTE OF FUNARIA (MUSCI)
Author(s) -
French J. C.,
Paolillo D. J.
Publication year - 1976
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.1537-2197.1976.tb11838.x
Subject(s) - biology , seta , meristem , sporophyte , anatomy , elongation , botany , apex (geometry) , shoot , materials science , metallurgy , ultimate tensile strength , genus
The removal of the calyptra from the sporophyte of Funaria causes the seta to thicken dramatically. The growth patterns of the seta‐thickened and normal sporophytes are similar in that in either case elongation proceeds from the activity of an intercalary meristem in the subapical region. The absence of the calyptra during elongation does not inhibit growth. The first effect of removing the calyptra is to allow for increased lateral expansion of the cells produced from the meristem. Subsequently, there is an increase in the number of cells seen in transverse sections, compared to what is seen in normal sporophytes. Improved procedures for surface sterilization and in vitro culture have allowed the growth of young, excised sporophytes to maturity. Using these culture procedures it is shown for the first time that thickened setae are capable of long term (indeterminate) growth if capsules do not form. The normal seta is shown to be doubly tapered, with the maximum diameter reached after the first ⅓ of the length of the seta is attained. The tapering of the normal seta seems to result from an interaction between the intercalary meristem and the calyptra, which is also tapered.