[农学]【双语植物育种14】Genetic_Transformation_and_Production_of_Transgenic_Plants.pptVIP

Some applications of genetic engineering to plant breeding Already there is a growing list of dicot crop species that have proved successful hosts for transformation including: alfalfa, apple, carrot, cauliflower, celery, cotton, cucumber, flax, horseradish, lettuce, potato, rapeseed, rice, rye, sugarbeet, soybean, sunflower, tomato, tobacco and walnut. In monocots, maize is leading the way, but is being followed by wheat, barley and rice. Some applications of genetic engineering to plant breeding Initial cultivar development using reconmbinant DNA techniques has focused on modifying or enhancing traits that relate directly to the traditional role of farming. These have included the control of insects, weeds and plant diseases. The first genetically engineered crops have now been released into large-scale agriculture (including, maize, tomato, canola, squash, potato, soybean and cotton) and other species are already in the pipeline. More recently work has focused on altering end-use quality (especially oil fatty acid, starch and vitamin precursors). Some applications of genetic engineering to plant breeding Engineering herbicide tolerance into crops represents a new alternative for conferring selectivity of specific herbicides. Two general approaches have been taken in engineering herbicide tolerance: ·Altering the level and sensitivity of the target enzyme for the herbicide · Incorporating a gene that will detoxify the herbicide As an example of the first approach, glyphosate, the active ingredient of herbicides such as Roundup, acts by specifically inhibiting the enzyme 5-enolpyruvylshimate-3-phosphate synchase (EPSPS). Tolerance to glyphosate has been engineered into various crops by introducing genetic constructions for the over-production of EPSPS. Some applications of genetic engineering to plant breeding The production of plants that are resistant to insect attack has been another application of genetic engineering with important implications