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POLAR GROWTH OF HORMOSIRA BÁNKSII ZYGOTES IN SHAKE CULTURE
Author(s) -
Sussex I. M.
Publication year - 1967
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.1537-2197.1967.tb10671.x
Subject(s) - shake , biology , rhizoid , zygote , population , botany , polar , human fertilization , embryo , microbiology and biotechnology , embryogenesis , anatomy , physics , demography , astronomy , sociology
Zygotes of the fucalean alga Hormosira banksii initiate rhizoidal outgrowths in stationary culture 15 hr after fertilization and are then recognizably polar. By 24 hr most embryos are two‐celled, and a few are four‐celled. In a dark‐grown population orientation of the developmental axis, as indicated by the direction of the rhizoidal outgrowth, was random around the vertical axis. In a unilaterally illuminated population the rhizoid usually emerged on the shaded side. Zygotes grown in light or darkness in shake culture, where they were continuously reoriented, usually developed as polar embryos, indicating that gradients of environmental factors are not required for initiation of polar growth. Some apolar embryos developed in stationary and shake cultures, but they were most frequent in dark shake cultures.