Scientists at Chinese Academy of Agricultural Sciences and Chinese Academy
of Tropical Agricultural Sciences characterized the transgene flow from
herbicide tolerant (HT) soybean (AG5601) to conventional soybeans. They
evaluated the natural out-crossing rate using 36 conventional soybean
varieties interplanted with AG5601. Then they evaluated the drift distance
of the HT gene (cp4 EPSPS) from AG5601 to soybean cv. Zhonghuang13 using the
progenies harvested from eight directions at different distance. The
relationship of gene flow of AG5601 with flowering synchronization days or
insect pollinators of each variety was analyzed using regression analysis.

Results showed that 32 of 36 tested conventional soybean varieties had
surviving progenies after two times of sprays of glyphosate, and 49 of
41,679 progenies were verified to be glyphosate-tolerant heterozygous
offspring. The farthest distance between AG5601 and cv. Zhonghuang13 at
which out-pollinating was still able to be observed was 15 meters.
Regression analysis showed a positive link between cross-pollination
frequency and flowering synchronization days or pollinator insects. Based on
the results, the researchers recommend that when HT soybean is released to
the field, it should be significantly separated with the conventional
soybean in space and cultivation time with efficient insect control during
flowering.

[link.springer.com]