Androgenic dihaploids from somatic hybrids between Solanum melongena and S. aethiopicum group gilo as a source of resistance to Fusarium oxysporum f. sp. melongenae

Abstract

Dihaploid plants were obtained through anther culture of somatic hybrids between eggplant and Solanum aethiopicum gilo. The androgenic origin of the dihaploids was demonstrated by ploidy determination (flow cytometry and chloroplast counting) and isozyme and molecular (I-SSR and RAPDs) analyses. The androgenic plants showed significant morphological variability in the traits analysed. Pollen viability in the diploid androgenic plants was drastically reduced with respect to the somatic hybrids; however most of the dihaploids produced parthenocarpic fruits. S. aethiopicum and the somatic hybrids showed complete resistance to fungal wilt caused by Fusarium oxysporum f. sp. melongenae. Out of the 41 dihaploids inoculated, 34 were symptomless. The population of androgenic plants developed may represent a useful source for introgression of the Fusarium resistance trait into eggplant.

Characterization of interspecific hybrids and first backcross generations from crosses between two cultivated eggplants (Solanum melongena and S. aethiopicum Kumba group) and implications for eggplant breeding

“…However, sexual hybrids often have a high degree of sterility (Daunay et al 1993;Isshiki and Taura 2003). Development of progenies with increased fertility from hybrids has been obtained by sexual crosses using the interspecific hybrids as female parents (Khan and Isshiki 2010) or by means of somatic hybridization followed by anther culture of the hybrids or of progenies obtained after crossing the tetraploid somatic hybrids with tetraploid S. melongena (Daunay et al 1993;Rizza et al 2002;Toppino et al 2008;Mennella et al 2010). In our case, by using the recurrent parents as males first backcross seeds, which we have used here for the characterization of the plants and fruits, could be obtained.…”

“…Although a first backcross generation to S. melongena has been reported (Schaff et al 1982), no records document introgression of S. macrocarpon genes into S. melongena. Interspecific sexual and somatic hybrids between S. melongena and S. aethiopicum are easier to produce and although they present a high degree of sterility, backcross generations to S. melongena with introgressions of S. aethiopicum have been obtained on occasion (Rizza et al 2002;Toppino et al 2008;Khan and Isshiki 2010;Mennella et al 2010). Therefore, generations derived from crosses between S. aethiopicum and S. melongena seem the most promising for the breeding of both crops.…”

“…melongenae and resistance to R. solanacearum in both species (Cappelli et al 1995;Collonnier et al 2001a;Daunay et al 1991;Hébert 1985;Rizza et al 2002), as well as resistance to spider mites in S. macrocarpon (Bletsos et al 2004), and resistance to root-knot nematodes in S. aethiopicum (Hébert 1985). Given that both gboma and scarlet eggplants are cultivated species, they do not present undesirable traits commonly present in wild relatives of eggplant.…”

“…S. aethiopicum Gilo and Aculeatum groups have been used to obtain somatic hybrids resistant to Ralstonia solanacearum (Daunay et al 1993;Collonnier et al 2001b) and to introgress Fusarium wilt resistance into S. melongena (Rizza et al 2002;Toppino et al 2008). Reports are not available describing use of the Kumba group for common eggplant breeding.…”

Regeneration of flax ( Linum usitatissimum L.) plants from anther culture and somatic tissue with increased resistance to Fusarium oxysporum

“…On the other hand, this phenomenon has been used as a source of genetic variability in the breeding programmes of many crops, e.g. tobacco (Flashman 1982), wheat (Larkin and Scowcroft 1981), Lotus corniculatus (Damiani et al 1990), cucumber (Toldi et al 1995), potato (Thieme et al 1995), tomato (Gavrilenko et al 2001) and egg-plant (Rizza et al 2002).…”