THESIS

Interspecific hybrids between wild and cultivated of S. melongena species
have been successful in only a few cases. Such as S. melongena x S. aethipoicum
(Daunay et al., 1993), S. melongena x S. indicum (Rao and Kumar, 1980; Rao and
Rao, 1984; Patel, 2001), S. melongena x S. sodomeum (Tudor and Tomescu, 1995), S.
melongena x S. macrocarpon (Schaff et al., 1982), S. melongena x S. insanum (Rao
and Rao, 1984), S. melongena x S. gilo (Kashyap et al., 2003) and S. melongena x S.
integrifolium (Rao and Baksh, 1979).
Moreover, embryo rescue was successfully used to recover hybrids of S.
melongena with S. khasianum (Sharma et al., 1980), S. sisymbrifolium (Sharma et al.,
1984; Blestsos et al., 1998) and S. torvum (Daunay et al., 1991; Blestsos et al., 1998)
but these hybrids were sterile. Fertility was reported in hybrids of S. melongena with
S. macrocarpon (Gowda et al., 1990) and S. torvum (Daunay et al., 1991) when
diploid hybrids (2x) were brought to the amphiploid status (4x) by colchicines
treatment. However, the successful in interspecific crosses have been obtained with
only few wild species. In such attempted, the hybrids have been developed through
embryo rescue. In addition, such hybrids have either been sterile or have had very low
pollen fertility. This may be due to pre- and post- pollination effects (Kashyap et al.,
2003).
Nevertheless, interspecific crosses between S. melongena and other Solanum
species, bearing interesting agronomical traits, have sometimes been limited by sexual
barriers (Collonnier et al., 2001). Crossability between S. melongena and species of
other genera or distant subgenera such as subgenus Archaesolanum, subgenus Potatoe
or subgenus Solanum is very low (Daunay et al., 1991). This may result from lack of
genetic information in one partner about the other, due to evolutionary divergence;
this is known as incongruity (Franklin et al., 1995).
However, plant regeneration from protoplast has been achieved in both
cultivated and wild species of S. melongena. The protoplast culture and somatic
hybridization would be useful in overcoming the pre- and post- fertilization breeding
barriers encountered during conventional breeding. Further, protoplast cultures are
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