Ultrastructural changes during growth and embryogenesis in carrot cell cultures

Cell Differentiation in Embryoids and Plantlets of Celery Tissue Cultures

“…3). The origin of the embryoids is similar to that found in tissue cultures of the wild and domestic carrot where the superficial cells of the cell aggregates give rise to the embryoids in the same way (Halperin and Wetherel, 1964;Halperin, 1967;Halperin and Jensen, 1967;McWilliam etal., 1974). The globular embryoids, free-floating in the medium, frequently show the remains of their attachments to the aggregate (Plate 1, No.…”

“…The problem was whether the embryoid developed from a single isolated cell, in the same way as the zygote, or was derived from cells within the large cell mass of an aggregate. Most of the evidence suggested that the embryoids were initiated from surface cells of the cell aggregates and, where viable single cells were present, these first divided to form an aggregate from which embryoids were initiated from the surface as before (Halperin and Wetherel, 1964;Halperin, 1967;Halperin and Jensen, 1967;Thomas, Konar and Street, 1972;Konar, Thomas and Street, 1972;McWilliams, Smith and Street, 1974). At this early stage of its development the tissue culture embryoid is not strictly comparable to the plant embryo since the latter originates from a single isolated cell, the zygote which divides directly to form the embryo, whereas the embryoid arises from a relatively large mass of un differentia ted cells.…”

Cell-Aging Related Configurations of Cortical Microtubules in Carrot (Daucus carota L.) Suspension Cells.

“…The previous work conducted using carrot suspension cells were addressed to cell culture but not to cell aging process (Israel and Steward 1966, Halperin and Jensen 1967, Fujimura and Komamine 1980, Lloyd et al 1988, Hawes 1985, Cyr et al 1987, Traas et al 1987). The efforts of those studies, if cytoskeleton was the topic, were mainly paid to the determining morphog enic potential of preprophase band (PPB) and spindle MTs (also see reviews on protoplast, Simmonds 1991, Fowke andWang 1992).…”

Somatic embryos from callus of Salix viminalis L

“…Somatic (Tomes, 1985). Embryogenic callus from willow shared characteristic features with embryogenic cell suspensions of carrot (Halperin and Jensen, 1967;Wochok, 1973) and Pennisetum purpureum and Panicum maximum (Karlsson and Vasil, 1986). …”