Advances in Transgenic Vegetable and Fruit Breeding

Abstract

Vegetables and fruits are grown worldwide and play an important role in human diets because they provide vitamins, minerals, dietary fiber, and phytochemicals. Vegetables and fruits are also associated with improvement of gastrointestinal health, good vision, and reduced risk of heart disease, stroke, chronic diseases such as diabetes, and some forms of cancer. Vegetable and fruit production suffers from many biotic stresses caused by pathogens, pests, and weeds and requires high amounts of plant protection products per hectare. United States vegetables farmers are benefiting from growing transgenic squash cultivars resistant to Zucchini yellow mosaic virus, Watermelon mosaic virus, and Cucumber mosaic virus, which were deregulated and commercialized since 1996. Bt-sweet corn has also proven effective for control of some lepidopteran species and continues to be accepted in the fresh market in the USA, and Bt-fresh-market sweet corn hybrids are released almost every year. Likewise, transgenic Bt-eggplant bred to reduce pesticide use is now grown by farmers in Bangladesh. Transgenic papaya cultivars carrying the coat-protein gene provide effective protection against Papaya ring spot virus elsewhere. The transgenic “Honey Sweet” plum cultivar provides an interesting germplasm source for Plum pox virus control. Enhanced host plant resistance to Xanthomonas campestris pv. musacearum, which causes the devastating banana Xanthomonas wilt in the Great Lakes Region of Africa, was achieved by plant genetic engineering. There are other vegetable and fruit crops in the pipeline that have been genetically modified to enhance their host plant resistance to insects and plant pathogens, to show herbicide tolerance, and to improve features such as slow ripening that extends the shelf-life of the produce. Consumers could benefit further from eating more nutritious transgenic vegetables and fruits. Transgenic plant breeding therefore provides genetically enhanced seed embedded technology that contributes to integrated pest management in horticulture by reducing pesticide sprays as well as improving food safety by minimizing pesticide residues. Furthermore, herbicide-tolerant transgenic crops can help reducing plough in fields, thereby saving fuel because of less tractor use, which also protects the structure of the soil by reducing its erosion. Transgenic vegetable and fruit crops could make important contributions to sustainable vegetable production and for more nutritious and healthy food. Countries vary, however, in their market standards of acceptance of transgenic crops. Biotechnology products will be successful if clear advantages and safety are demonstrated to both growers and consumers.