**3.5 In planta** *Agrobacterium* **mediated transformation**

The development of the in planta transformation system (Floral-dip method and Vacuum infiltration) radically accelerated research in basic plant molecular biology. These methods have been targeted mostly for meristems or other tissues that ultimately give rise to gametes.

Soybean transformation also has been subjected by infecting partially germinated seeds with *Agrobacterium* to vacuum infiltration with high frequency (de Ronde et al., 2001). In planta soybean transformation has also been carried out by Lei et al, (1991); Liu et al., (1996) and Hu & Wang (1999). They introduced foreign DNA by pollen tube pathway and by ovarian injection. Such procedures pass tissue culture steps but for routine transformation physiological conditions of recipient plant, type and concentration of DNA, location of ovary etc are critical factors. By such methods, they produced new varieties that yield batter protein and oil contents. But Li et al. (2002) were not able to produce positive results by pollen tube pathway. They reported that DNA was inside the cell but not integrated into soybean genome. Shou et al., 2002 also performed pollen tube pathway transformation procedure using different soybean cultivars. They observed that only 2% progenies were partially resistant to herbicide. However, no plant was confirmed by Southern blotting carrying transformed T-DNA as well as by histochemical GUS assay. They concluded that pollen tube pathway transformation technique is not reproducible for soybean.
