Environmental risk assessment of glufosinate-resistant soybean by pollen-mediated gene flow under field conditions in the region of the genetic origin

Risk assessment of hybrids between genetically modified soybean and its wild relatives

“…Kan et al (2015) measured the F 1 and F 2 hybrids of four wild soybeans and glyphosate-resistant soybean in a greenhouse and found that hybrids had similar pod and seed numbers per plant as their wild relatives. Field experimental studies conducted by Yook et al (2020) and Guan et al (2015) also found that F 1 and F 2 hybrids (especially F 2 hybrids) exhibited intermediate characteristics of their parental soybeans in their vegetative and reproductive stages, and all parameters were close to those of wild soybean. The results of previous studies (Guan et al 2015;Kan et al 2015;Yook et al 2020) indicated that hybrids acquired by gene flow from GM soybean to wild soybean were not associated with a fitness cost when there was no glyphosate selection pressure, hybrids resulting from gene flow from GM soybean to wild soybean possess a higher potential of persistence in ecosystem.…”

“…Importantly, there were no significant differences in F 2 and F 3 RR, RS or SS plants in pod and seed numbers per plant, the EPSPS gene and its copy number did not significantly affect the fecundity of the hybrids. In a two-year field experiment, Yook et al (2020) reported that F 1 and F 2 hybrids had a similar number of pods and seeds as wild soybean, and no differences were found for 100-seed weight between F 1 hybrid and wild soybeans; however, F 2 hybrids had a higher 100-seed weight than their wild soybean counterparts. Similar to those of the studies described previously (Yook et al 2020), our results also showed that F 2 and F 3 hybrids had significantly higher 100-seed weights than their wild soybean counterparts, and no parameters significantly differed among RR, RS and SS in the F 2 or F 3 population.…”

“…However, wild soybean commonly grows throughout almost all of China, and their distributions largely overlap with the distributions of cultivated soybean fields, especially in northeastern and southeastern China (Wang and Li 2012). While more favorable conditions, such as flowering synchrony and certain climatic conditions, are available, greater gene flow may be observed (Yook et al 2020).…”

“…Individuals with a higher fitness level might be associated with a higher ability to adapt to the environment and may therefore be beneficial for the establishment of a new plant generation. At present, a few studies were conducted to evaluate the growth performance of hybrids between GM soybean and wild soybean under greenhouse or field conditions (Guan et al 2015;Kan et al 2015;Yook et al 2020). Kan et al (2015) measured the F 1 and F 2 hybrids of four wild soybeans and glyphosate-resistant soybean in a greenhouse and found that hybrids had similar pod and seed numbers per plant as their wild relatives.…”

“…The expression of endogenous genes such as Bt andCP4-EPSPS could improve resistance to insects or herbicides; if the transgene is normally expressed in crop-wild hybrids and progenies and inherited between different generations, the transgene may change a certain trait of wild plants, possibly leading to further undesired environmental consequences (Lu 2008). Therefore, to evaluate the risk of GM soybean and its hybrids resulting from gene flow, it is necessary to investigate protein expression data for assessing and monitoring the biosafety of GM crops and hybrids; however, previous studies mainly focused on vegetative and reproductive hybrids (Guan et al 2015;Kan et al 2015;Yook et al 2020), and the protein levels in hybrid plants were not well investigated. In addition, wild soybean seeds have strong dormancy, while cultivated soybean seeds do not (Kubo et al 2013).…”