摘要 |
HYBRIDIZATION PROCESS UTILIZING A COMBINATION OF CYTOPLASMIC MALE STERILITY, CYTOPLASMIC HERBICIDE TOLERANCE, AND HERBICIDE TOLERANCE ATTRIBUTABLE SOLELY TO NUCLEAR GENES The present invention provides a convenient route for producing a predetermined hybrid variety of a crop which is capable of undergoing both self-pollination and cross-pollination. Cytoplasmic male sterile plants which also exhibit cytoplasmic herbicide tolerance (i.e., to a Type A herbicide) and tolerance to a different herbicide attributable solely to nuclear genes (i.e., to a Type B herbicide) are the key plants for use in the present process. The maintainer and restorer plants exhibit tolerance to different herbicides (i.e., to either a Type A herbicide or a Type B herbicide). The economical bulk planting of the parent plants is made possible during each step of the process. For instance, cytoplasmic male sterile plants, plants resulting from the self-pollination of a maintainer, and restorer plants can be grown in a substantially random population, with the self-pollinated maintainer plants being destroyed by an appropriate herbicide prior to pollination, and the selfpollinated restorer plants being destroyed by an appropriate herbicide immediately following pollination or in the subsequent generation. The process of the present invention is applicable to grain crops, forage crops, seed propagated fruits, seed propagated ornamentals, and industrial species. In a particularly preferred embodiment a predetermined variety of Brassica napus (i. e., rape or improved forms thereof known as canola) is formed which is the product of cross-pollination. |