Hybrid fitness and the potential for gene flow between cultivated rice, Oryza sativa and its wild relative, Oryza rufipogon.

摘要

Gene flow resulting from hybridization between domesticated plants and their wild relatives can be either beneficial or may have harmful effects depending on the types of genes transferred. This dissertation project contributes to a broader study which seeks to evaluate the level of gene flow between cultivated rice (Oryza sativa) and its wild relatives, and to determine the potential impact of any gene flow. The specific aim of this dissertation research project is to assess the fitness effects of possible gene flow and hybridization between transgenic rice and native populations of wild rice (Oryza rufipogon). The use of GM plants has increased dramatically world wide. The crops are modified not only for yield enhancing features such as resistance to drought, pests etc., but also for novel compounds such as vitamins, vaccines, etc. GM cultivated rice crops may potentially be planted in locations with wild rice present, so this is an important issue. The results of the dissertation study show that the hybrids formed between GM cultivated rice and wild rice are viable and fertile. The fitness of hybrids is not significantly lower than the parental plants. There is the possibility of gene flow between cultivated rice and wild rice via hybrids wherever cultivated rice and wild rice grow together.