Wide Hybridization

Soybean (Glycine max) is becoming one of the major oilseed crops of the country and earning foreign exchange from soya meal export. The wealth of genetic diversity from exotic germplasm including soybean’s progenitor G. soja and wild perennial species of the subgenus Glycine including G. tomentolla has not been utilized/exploited fully so far. Glycine soja is an excellent source of genetic variability, although, it harbors several undesirable genetic traits, for example, vining, lodging susceptibility, lack of complete leaf abscission, seed shattering, and small black coated seeds (Carter et al., 2004). However, G. soja has been shown to be more genetically diverse than G. max (Nichols et al., 2007) and the undesirable traits can be separated from the desirable ones during the course of selection in successive backcross generations and possibly through marker assisted selection. Attempts to broaden the genetic base of soybeans by utilizing G. soja have been reported by Hartwig (1973), Ertl and Fehr (1985), Carpenter and Fehr (1986) and Carter et al. (2004). Small seeded cultivars (Fehr et al.,1990a, b; Carter et al., 1995) have been developed where G. soja was used as a non-recurrent parent. The small seeded cultivars are used for sprouts and the fermented Japanese product natto. Qian et al. (1996) have identified accessions of G. soja that are potential sources of additional genes that restrict nodulation of soybean with specific strains of Bradyrhizobium. Introgression of such genes could result in soybean cultivars that exclude some of the indigenous strains and become nodulated with commercial strains that are more efficient at fixing nitrogen. Glycine soja harbors genes for resistance to soybean cyst nematode (Kabelka et al., 2006), higher seed yield (Concibido et al., 2003) and is a rich source of genetic diversity (Ohara and Shimamoto, 2002). These