Premium
FACTORS DETERMINING VARIOUS FORMS IN CLADOSIPHON ZOSTERAE (PHAEOPHYCEAE)
Author(s) -
Lockhart Joan Conway
Publication year - 1979
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.1537-2197.1979.tb06290.x
Subject(s) - biology , crustose , thallus , sporangium , botany , spore , germination , gemma , morphology (biology) , sporophyte , spore germination , algae , zoology
The brown alga Cladosiphon zosterae (J. Ag.) Kylin (Chordariaceae) is found to exist in culture in a variety of forms, including filaments, discoid or crustose forms, and two types of erect cylindrical thalli. Asexual spores from plurilocular sporangia of each form can produce any and all forms. Three factors controlling morphological expression in C. zosterae have been identified. These factors include: (1) heteroblasty (formation of filamentous and discoid germlings as a consequence of alternate modes of spore germination), which was independent of all environmental factors tested including temperature, photoperiod, nitrogen source, and general fertility of the growth medium; (2) influence of certain nitrogen sources, notably ammonium, which induce a compact discoid or crustose form; and (3) a morphogenetic factor presumed to be bacterial which determines mode of development and subsequent morphology of the erect Cladosiphon thallus.