In planta soybean transformation technologies developed in China: Procedure, confirmation and field performance

Soybean is a recalcitrant species for in vitro manipulation. Chinese scientists developed two in planta non-tissue culture soybean transformation procedures: (1) via the "pollen-tube-pathway" to introduce exogenous genomic total DNA of Glycine gracilis, the seed of which consisted of 50% protein, and (2) "ovarian injection" with exogenous plasmid DNA containing atrazine-resistant gene. A high yield and high seed protein (45.44%) cultivar, 'Heisheng 101', resulted from the first method, and atrazine-resistant F-1, F-2, and F-3 plants were obtained from the second method. Both exogenous single-genic Mendelian traits anti multi-genic quantitative traits were transferrable with these simple and inexpensive procedures. However, some controversy exists with the acceptance of these novo procedures; mainly because instead of the standard Southern blotting, the RAPD and dot blotting techniques were used in the molecular confirmation of the transgenic status in the reported studies.