Rapeseed plants have been regenerated after fusion between protoplasts bearing cytoplasms of different genera Cybrids combine, in a first experiment Brassica napus chloroplasts and a cytoplasmic male sterility (cms) trait coming from Raphanus sativus, in a second experiment chloroplasts of a triazine resistant Brassica campestris and cms trait from Raphanus sativus Transfer of chloroplasts has been confirmed by restriction cp DNA analysis and two dimensional thylakoid protein electrophoresis These plants may be very useful for Brassica hybrid seed production

Intergeneric cytoplasmic hybridization in cruciferae by protoplast fusion

Grafting of herbaceous vegetable and ornamental crops

Doubled Haploid Production in Crop Plants

SummaryRapeseed plants have been regenerated after fusion between protoplasts bearing cytoplasms of different genera. Cybrids combine, in a first experiment Brassica napus chloroplasts and a cytoplasmic male sterility (cms) trait coming from Raphanus sativus, in a second experiment chloroplasts of a triazine resistant Brassica campestris and cms trait from Raphanus sativus. Transfer of chloroplasts has been confirmed by restriction cp DNA analysis and two dimensional thylakoïd protein electrophoresis. These plants may be very useful for Brassica hybrid seed production.

In the multicellular organisms of higher plants, plasmodesmata provide pathways for intimate symplasmic communication between neighboring cells. The arguments summarized in the present review demonstrate that plasmodesmata are diverse and highly dynamic structures. Differences in the plasmodesmal origin and modifications of the plasmodesmal structure and functioning at the various cell interfaces are the basic means which give rise to a complicated and flexibile symplasmic network. This complex communication system is discussed to serve a significant role in the coordinated development and in the concerted physiological functioning of the cells within the plant tissues, organs, and organisms.

Primary and secondary plasmodesmata: structure, origin, and functioning

Plants were regenerated from protoplast fusion experiments with haploid Solanum tuberosum L. and an atrazine resistant biotype of the normally susceptible S. nigrum L. Sixty clones which were unlike the parents were selected by types of hairs and leaf pigmentation of young shoots and characterized by: chromosome numbers, response to atrazine, branching, hairs of the calyx, shapes and pigmentation of leaves, and morphology of flowers. Twenty five clones showed vegetatively stable differences from the parental clones; enough combinations of mixed characters suggested the clear origin from fusants of at least nine clones. Observed diversities within and between protoplastderived clones are interpreted as expressions of variation during the development of the regenerants.

Somatic hybridization of an atrazine resistant biotype of Solanum nigrum with Solanum tuberosum

Comparative Studies on Protoplast Regeneration in Herbaceous Species of the Dicotyledoneae Class

Heterospecific chimeralSolanum nigrum (+)Solanum tuberosum plants were obtained by cell grafting in protoplast co-cultures. Periclinal, sectorial, and mericlinal chimeras have been identified by various morphological and cytological characteristics. Morphogenesis predominantly began in periclinal chimeral organization. Cells of different species have been found to be interconnected by secondary plasmodesmata. Plantlets of all chimeral lines were grown to flowering under tissue culture conditions and some also in the greenhouse. Aspects of organogenesis and interspecific cooperation are discussed.

Gudrun Mordhorst

Papers

Somatic hybridization of an atrazine resistant biotype of Solanum nigrum with Solanum tuberosum

Comparative Studies on Protoplast Regeneration in Herbaceous Species of the Dicotyledoneae Class

Plant cell graft chimeras obtained by co-culture of isolated protoplasts

Haploid Solanum dulcamara L.: Shoot culture and plant regeneration from isolated protoplasts

Protoplast Gel Fusion