Sexual and somatic hybridization

摘要

With the introduction of cell and tissue culture techniques of plants in vitro, it is now possible to produce hybrids between distantly related, sexually incompatible species. In the overview two approaches will be discussed; the gametic and the somatic system.In the gametic system hybrids are produced from fusion of ordinary gametes. Fertilization can be performed naturally but to obtain further growth and development of the hybrid, the fertilized ovule or ovary has to be isolated and cultured in vitro shortly after pollination (ovule rescue). If development of the hybrid can reach the embryo stage, but no further development is possible on the plant, the embryo has to be rescued and cultured in vitro (embryo rescue). It is also possible to obtain hybrids after pollination and fertilization in vitro using the whole female reproduction apparatus or isolated ovules (in vitro pollination).The somatic system involves fusion of isolated somatic cells that have been isolated as protoplasts before fusion. Thus, ordinary vegetative, somatic cells can be forced to fuse with each other to produce somatic hybrids.The two different techniques enable the production of hybrids that cannot be produced in nature. In this overview an attempt will be made to describe, compare and discuss the potentials and the limitations of gametic and somatic hybridizations performed in vitro.