Articles
ATTEMPT OF MALE CYTOPLASMIC STERILITY INTRODUCTION BY INTERGENERIC FUSION IN CULTIVATED TOMATO
The technical reason for their use in preference to the pure-lines varieties rests on their greater productivity due to heterosis, on the greater uniformity of the plants and also on the easiness with which one can put together inside the hybrid the resistances introduced in their parental lines.
Nevertheless, the cost of hybrid seeds is very high.
Most of this price has little to do with the cost of the operations of emasculation and manual pollination but mainly reflects the honoring of the obtainer’s rights.
Under these circumstances, the need of hybrid has to be looked into afresh (Simmonds, 1979).
Plant protoplasts for use in somatic hybridization are routinely isolated through the use of cell wall-degrading enzymes.
Protoplasts may be isolated from a wide range of tissues or cell types (Vasil and Vasil, 1980). Leaf tissues have been used as protoplast sources in most hybridization studies because of their availability and the satisfactory yields that can be obtained from them (O’Connell and Hanson, 1985).
Heterokaryon survival and hybrid colony development is influenced by the initial condition of the donor cells or tissues as well as protoplast isolation and fusion procedures.
Plant regeneration methods similar to those for inducing morphogenesis in the parental species are generally used but in some cases the regeneration media are modified to stimulate morphogenesis in hybrid cells (Douglas et al., 1981).
Our aim in this note was to regenerate cytoplasmic male sterile tomato obtained by protoplast fusion between Lycopersicon esculentum and Nicotiana tabacum. Several somatic hybrids, including L. peruvianum + P. hybrida (Tabaizadeh, 1983) and L. esculentum + S. pennellii (Hassanpour-Estahbanati, Turpin and Demarly, 1985) have been already realized in our laboratory.