Ecological and Evolutionary Consequences of Gene Flow through Pollen from Transgenic Crops to Their Wild Relatives

Abstract

The rapid progress in biotechnology has significantly promoted the development and production of genetically modified (GM) crops. The extensive global cultivation of GM crops has generated great benefits, which may provide opportunities for solving the problems inherent in world food security, but it has also aroused considerable biosafety concerns worldwide. Among these, the potential environmental consequences created by possible transgene escape from a GM crop to its nonGM crop counterparts and wild or weedy relatives via gene flow are the most debated biosafety issues internationally. Gene flow indicates the movement of genes or genetic materials from one plant population into another. There are a range of predicted possible environmental and evolutionary consequences such as the creation of new weeds, change of fitness-related characters, and loss of genetic diversity in crop landraces and wild relatives) caused by wild transgene flow. In addition, transgene flow also arouses biosafety concerns for food/feed and health and socio-economics and ethics. Through pollenmediated gene flow, a transgene can move from a GM crop into populations of a wild relative, and persist or disseminate in the wild population through further hybridization and introgression between the GM crop and wild relative. If a transgene can express in wild plants as it does in the GM crop, the transgene may change a certain trait of the wild plants, possibly leading to further undesired consequences. If a transgene can alter the fitness of wild plants and the dynamics of the wild populations, the introgression of the transgene in the wild population may cause either local extinction of the population or make the wild population more invasive and competitive. Therefore, a wide variety of possible ecological and evolutionary consequences of gene flow through Pollen from transgenic plants to their wild relatives are discussed on the basis of previous work