A new method for evaluating flowering synchrony to support the temporal isolation of genetically modified crops from their wild relatives

Abstract

Hybridization between crops and their wild relatives potentially threatens the genetic identity of the wild plants, particularly in the case of genetically modified crops. Only a few studies have examined the use of temporal isolation to prevent hybridization, and the indices used in those studies, (e.g., the days of flowering overlap), are not precise to evaluate the degree of synchrony in flowering. Here we propose a flowering similarity index that can compare the degree of flowering synchrony between two relevant species and measure the efficiency of temporal isolation. The results showed that the flowering similarity index predicts the likelihood of hybridization much better than the number of flowering-overlap days, regardless of different flowering patterns among cultivars. Thus, temporal isolation of flowering or flowering asynchrony is the most effective means in preventing hybridization between crops and their wild relatives.

Likelihood assessment for gene flow of transgenes from imported genetically modified soybean (<i>Glycine max</i> (L.) Merr.) to wild soybean (<i>Glycine soja</i> Seib. et Zucc.) in Japan as a component of environmental risk assessment

“…It has been reported that synchrony of flowering period has a strong correlation with the number of hybrids produced between cultivated and wild soybeans ( Ohigashi et al 2014 ). Therefore, in addition to geographic overlap of soybean and wild soybean along transportation routes, temporal overlap ( i.e.…”

The role of allochrony in speciation

“…Clusters formed even in the absence of selection; adding weak disruptive selection to the model “promoted long‐lived transient clusters” (Devaux & Lande, ). Interestingly, temporal isolation has been suggested as a way of reducing gene flow between crops and their wild relatives (Ohigashi, Mizuguti, Yoshimura, Matsuo, & Miwa, ).…”

Scientific advice to the European Commission on the internal review submitted under Regulation (EC) No 1367/2006 on the application of the provisions of the Aarhus Convention against the Commission Implementing Decision 2015/687 to authorise genetically modified oilseed rape MON88302

“… Gene flow to wild relatives: The EFSA GMO Panel considered that the introduced cp4 epsps gene in oilseed rape MON88302 is not expected to change its ability to hybridise with sexually-compatible wild relatives (EFSA, 2014a). Oilseed rape is known to spontaneously hybridise with some sexually-compatible wild relatives (Scheffler and Dale, 1994;Devos et al, 2009;Ellstrand et al, 1999Ellstrand et al, , 2013Andersson and de Vicente, 2010;Liu et al, 2010Liu et al, , 2012Liu et al, , 2013Huangfu et al, 2011;Tsuda et al, 2011;de Jong and Hesse, 2012;Ohigashi et al, 2014;Luijten et al, 2015). Several oilseed rape  wild relative hybrids have been reported in the scientific literature, but under field (cultivation) conditions transgene introgression has only been confirmed for progeny of oilseed rape  B. rapa hybrids (Hansen et al, 2001(Hansen et al, , 2003Warwick et al, 2003Warwick et al, , 2008Norris et al, 2004;Jørgensen, 2007;Ellstrand et al, 2013).…”