Premium
MORPHOLOGY AND ULTRASTRUCTURE OF EMBRYOGENIC CELL SUSPENSION CULTURES OF PANICUM MAXIMUM (GUINEA GRASS) AND PENNISETUM PURPUREUM (NAPIER GRASS)
Author(s) -
Karlsson Sylvia B.,
Vasil Indra K.
Publication year - 1986
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.1537-2197.1986.tb12128.x
Subject(s) - pennisetum purpureum , biology , ultrastructure , panicum , botany , subculture (biology) , amyloplast , nucleolus , vacuole , cell wall , pennisetum , cytoplasm , microbiology and biotechnology , plastid , biochemistry , dry matter , chloroplast , gene
Morphological and ultrastructural changes during the growth of embryogenic cell suspension cultures of Panicum maximum and Pennisetum purpureum have been studied. The suspensions consist almost entirely of cell aggregates of 50–75 embryogenic cells. The cell aggregates vary in size from 90–400 μm in P. maximum and from 70–340 μm in P. purpureum. Following the period of exponential growth starch grains gradually disappear and vacuolation increases. Ten to 16 days after subculture, P. maximum cells enlarge and separate from each other, and organized embryo‐like structures appear. Ultrastructural studies show that the cell aggregates are made up of discrete, individual groups of 2–6 cells each. Each cell group appears to arise from a single cell and breaks away from the ‘mother group’ as cell divisions continue. The embryogenic cells are small (20 μm), isodiametric with many starch grains and contain a large nucleus with a prominent nucleolus. Extensive profiles of endoplasmic reticulum, many small peripheral vacuoles, and several amyloplasts are present. Plasmodesmatal connections exist only between cells within a cell group but not between cells of different cell groups in the large cell aggregates.