INTERSPECIFIC SOMATIC HYBRIDIZATION BETWEEN SOLANUM-TUBEROSUM L AND S-BULBOCASTANUM DUN AS A MEANS OF TRANSFERRING NEMATODE RESISTANCE

Interspecific somatic hybrids were produced between tetraploid Solanum tuberosum and a nematode-resistant accession of the diploid species Solanum bulbocastanum by protoplast fusion. Hybrid cells were selected using dual fluorescent labeling of protoplast preparations prior to fusion. Hybridity of regenerated plants was confirmed with a combination of morphological assessment, chromosome counting and isozyme analysis. Somatic hybrids had the same level of resistance to infection by race 1 of the nematode Meloidogyne chitwoodi as the S. bulbocastanum parent used in the fusion. Some of the somatic hybrids were fertile as females when crossed with tetraploid S. tuberosum breeding lines. Thus, these hybrids can be used in a potato improvement program to incorporate a valuable pest resistance.