Regeneration of intergeneric somatic hybrid plants between Atropa belladonna L. and Hyoscyamus muticus L.

Abstract

In the present experiments, cell suspension derived protoplast of Atropa belladonna L. (2 n = 72) var acuminata and protoplasts of an achlorphyllous mutant cell line of Egyptian henbane, Hyoscyamus muticus (2 n = 28) were fused to obtain intergeneric somatic hybrid plants. The somatic hybrid plants possessed variable chromosome complements. Those plants with a chromosome number of around 100 and with both parental genomes distinguished on the basis of chromosome size were easier to establish in the glasshouse. Plants with multiple complements (chromosome number = 178) were grossly aberrant types and very difficult to maintain. The work involved complementation at the intergeneric level within the same tribe and evidence of chromosome elimination of Atropa chromosomes was obtained. The somatic hybrid plants developed with intermediate types of leaves and altered characteristics reflecting expression of both the genomes. In one of the somatic hybrid clones, SH-15, the pentamerous orientation of the whorls of sepals, petals and anthers in both the parents was altered to a hexamerous form. Further, the parents possess a bilocular ovary and this was altered to a trilocular form in this somatic hybrid. Plants that have responded better in their development in the glasshouse had a near tetraploid chromosome number of H. muticus and a near haploid chromosome number of A. belladonna. The presence of complementary bands of esterases and peroxidases as studied in the line SH-15, affirmed the hybrid nature.