Bootstrap simulations for evaluating the model estimation of the extent of cross-pollination in maize at the field-scale level

Abstract

With the recent advent of genetic engineering, numerous genetically modified (GM) crops have been developed, and field planting has been initiated. In open-environment cultivation, the cross-pollination (CP) of GM crops with wild relatives, conventional crops, and organic crops can occur. This exchange of genetic material results in the gene flow phenomenon. Consequently, studies of gene flow among GM crops have primarily focused on the extent of CP between the pollen source plot and the adjacent recipient field. In the present study, Black Pearl Waxy Corn (a variety of purple glutinous maize) was used to simulate a GM-maize pollen source. The pollen recipient was Tainan No. 23 Corn (a variety of white glutinous maize). The CP rate (%) was calculated according to the xenia effect on kernel color. We assessed the suitability of common empirical models of pollen-mediated gene flow (PMGF) for GM maize, and the field border (FB) effect of the model was considered for small-scale farming systems in Asia. Field-scale data were used to construct an optimal model for maize PMGF in the maize-producing areas of Chiayi County, southern Taiwan (R.O.C). Moreover, each model was verified through simulation and by using the 95% percentile bootstrap confidence interval length. According to the results, a model incorporating both the distance from the source and the FB can have optimal fitting and predictive abilities.

Incorporating the field border effect to reduce the predicted uncertainty of pollen dispersal model in Asia

“…The dispersal models with the modified Cauchy kernel (r = 0.833) and the compound exponential kernel (r = 0.834) displayed favorable results in the CP rate prediction. As described in our previous study, adding the FB effect into the models also improved the predictive ability of models 33 . In another study, the highest R 2 of the fitting result of log/log model was 0.91, when the field included a 17 m empty space between the source and recipient 21 .…”

“…K is the average grain number per cob. Meteorological data were collected from the meteorological station at geographic coordinates 23° 35′ N, 120° 27′ E, and an altitude of 20 m. The detailed experimental setup was described in our previous study 33 . The study complies with relevant institutional, national, and international guidelines and legislation.…”