Apomixis and its Application in Crop Improvement

Seed is formed in some species of higher plants by an asexual method of reproduction called apomixis. Apomixis can either prevent breeding progress or be a useful tool of the plant breeder. The first requirement for successful improvement of apomictic species is the availability of sexual or partially sexual plants for use as female parents in a hybridization program. Although the embryo is formed without union of the male and female gametes, pollination is necessary in many apomicts for full development of the embryo and endosperm. A progeny test combined with cytological study of megasporogenesis and embryo sac development are usually required to confirm the presence of apomixis and to identify the mechanism. Environmental factors may affect the stability of the reproductive process in facultative apomicts. Commercial seed production of obligate apomicts is simple and involves the same general principles that apply to vegetatively reproduced cultivars.