Alternative Morphogenetic Events in Cell Suspensions

Factors involved in the production of plantlets from date palm callus cultures

“…A decline in plantlet formation from date palm callus is not yet evident . Decreases in the morphogenic ability of calli derived from other plants has been noted (HALPERIN, 1966 ;THOMAS & STREET, 1972) . Plantlet formation was found to be a nonsynchronous process and usually fewer than 5-20 plantlets are produced from a single culture although as many as 500 embryoids in all stages of development may occur .…”

Arabinogalactan proteins and plant differentiation

“…The cell cultures contain several cell types including large vacuolated cells and small, dense, highly cytoplasmic cells often present in small clumps, the pro-embryogenic masses [ 19]. The pro-embryogenic masses (PEMs) can develop into somatic embryos with a very high efficiency.…”

Natural and induced variation in tissue culture

“…Aneuploid changes, typically involving gain or loss of a few chromosomes, have been reported (BAYLISS & GOULD, 1974 ;DE TOROK & WHITE, 1960 ;HALPERIN, 1966 ;HEINZ & MEE, 1969HEINZ et al, 1969;KAo et al, 1970;MUIR, 1965;Mu-RASHIGE & NAKANO, 1966NICKELL & MARETZKI, 1972 ;NORSTOG et al, 1969 ;SACRISTAN & LUTZ, 1970 ;SACRISTAN & MELCHERS, 1969 ;SHIMADA & TABATA, 1967 ;SHIMADA et al, 1969;SINGH et al, 1972). Structural changes also occur resulting in lagging chromosomes, bridges,, and multipolar configurations especially after repeated passages in tissue culture (BAYLISS, 1973(BAYLISS, ,1975COOPER et al, 1964;VENKETESWAREN, 1962VENKETESWAREN, ,1963.…”

“…In comparative studies of the effects of gamma radiation on young seedlings and callus cultures of Phaseolus (BAJAJ, 1968(BAJAJ, , 1970BAJAJ et al, 1968BAJAJ et al, , 1970, tobacco (VENKETESWAREN & PARTENEN, 1964, 1966 Pharbitis nil (RAQ et al, 1976) and Petunia inj7uta striking differences in radiosensitivity were observed between organized vs. disorganized growth. For example, in tobacco, low doses of 650 and 1300 R produced initial morphological effects on seedlings such as leaf stunting and apical meristem injury, but as the seedlings were allowed to grow for 80 days, these early effects disappeared.…”