Photosynthetic and chlorophyll fluorescence characteristics of transgenic glyphosate-tolerant soybean

The photosynthetic characteristics,chlorophyll fluorescence and growth fitness parameters of transgenic glyphosate-tolerant soybean 40-3-2 were investigated to assess the risk of invasive weed population to the ecological environment of China.The results indicated that transgenic 40-3-2 leaves in flowering stage had lower net photosynthetic rate(Pn) than that of cultivated soybean Hedou 13,but had superior water utility efficiency(WUE) with higher drought adaptability.Its chlorophyll fluorescence showed a low level of photoinhibition(lower Fv/Fm) and higher PSII photochemistry efficiency all day.On the contrary,the cultivated Hedou 13 had severely reduced Fv/Fm value at midday.Even so,there was no yield advantage of transgenic 40-3-2 observed in field when herbicide selective pressure was absent.These results suggested that the transgenic soybean 40-3-2 has little potential to be invasive.