Somatic hybrid plants produced by electrofusion between Solanum melongena L. and Solanum torvum Sw

Abstract

Somatic hybrid plants between eggplant (Solanum melongena) and Solanum torvum have been produced by the electrofusion of mesophyll protoplasts in a movable multi-electrode fusion chamber. Using hair structure as a selection criteria, we identified a total of 19 somatic hybrids, which represented an overall average of 15.3% of the 124 regenerated plants obtained in the two fusion experiments. Several morphological traits were intermediate to those of the parents, including trichome density and structure, height, leaf form and inflorescence. Cytological analyses revealed that the chromosome numbers of the somatic hybrids approximated the expected tetraploid level (2n=4x=48). Fifteen hybrid plants were homogeneous and had relatively stable chromosome numbers (46-48), while four other hybrids had variable chromosome numbers (35-48) and exhibited greater morphological variation. The hybridity of these 19 somatic hybrid plants was confirmed by analyses of phosphoglucomutase (Pgm) and esterase zymograms.

Production and characterization of intergeneric somatic hybrids through protoplast electrofusion between potato (Solanum tuberosum) and Lycopersicon pennellii

“…Features of the somatic hybrids, including retarded development, diffÉculties in rooting and particularly high sterility certainly resulted in partial somatic incompatibility between genomes of remote species even through somatic cell fusion. Very similar problems have been reported for interspecific and intertribal somatic hybrids of eggplant (Gleddie et al 1986;Sihachakr et al 1988Sihachakr et al , 1989 and Brassica (Glimelius et al 1990) respectiveley, as well as for the first somatic hybrids of potato (S. tuberosum) with tomato (L. esculentum) obtained by Melchers et al (1978).…”

A somatic hybrid between Solanum integrifolium and Solanum violaceum that is resistant to bacterial wilt caused by Ralstonia solanacearum

“…Protoplast culture and plant regeneration Numerous attempts to transfer disease resistance from wild eggplant species to the edible S. melongena by producing somatic hybrids have been reported (Gleddie et al 1986;Guri and Sink 1988;Sihachakr et al 1989;Daunay et al 1993;Jarl et al 1999;Collonnier et al 2001). These attempts, however, were unsuccessful from an agronomical point of view, because undesirable traits such as unattractive fruit shape or poor taste were frequently also transferred to the edible eggplant.…”

“…However, resistance to bacterial wilt has been described in several wild species of the genus Solanum (Sakata et al 1989). To transfer the resistant traits to the edible eggplant, some workers have attempted to produce somatic hybrids by protoplast fusion between eggplant and related wild species (Guri and Sink 1988;Sihachakr et al 1989;Stattmann et al 1994;Jarl et al 1999). This technique has been preferred to sexual crossing, because most sexual hybrids in Solanum have been obtained only through the culture of embryos; moreover, F1 plants were mostly sterile (McCommon and Homa 1983).…”

The potential of somatic hybridization in crop breeding

“…sisymbrifolium (Gleddie et al ., 1986) and S . torvum (Guri & Sink, 1988b ;Sihachakr et al ., 1989) have been produced . Preliminary evaluation of the agronomic traits exhibited by these somatic hybrids reveals that the desired properties have been incorporated but their high sterility limits the potential value in future breeding programmes .…”