IN-VITRO REGENERATION AND CYTOLOGICAL CHARACTERIZATION OF SHOOTS FROMLEAF EXPLANTS OF 3 ACCESSIONS OF SOLANUM-COMMERSONII

In vitro culture of explants were used to apply genetic or cell engine rring techniques to the sexually incompatible potato relative Solanum commersonii (2n = 2x = 24) Three accessions of S. commersonii were tes ted for regeneration from leaf explants using six different protocols. A two step-regeneration procedure gave the best results. Genetic vari ability for regeneration ability was found between accessions, and bet ween clones within accessions. The accession PI 472834 regenerated at highest frequency. Clones with high regeneration ability were selected . Approximately 60% of regenerated plants were diploids and 40% were t etraploids. A very low frequency of chimeras was found. Leaf shape and chloroplast counts in guard cells were shown to be quick and reliable methods for estimating ploidy levels. Use of the diploid and tetraplo id regenerants obtained for potato breeding is discussed.