Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 364

Flower buds are picked from healthy plants. After surface sterilization, the anthers are excised from the buds and cultured unto an appropriate tissue culture medium. The pollen grains at this stage would be in the uninucleate microspore stage. In rice the late uninucleate stage is preferred. Callus formation starts within 2–6 weeks, depending on the species, genotype, and physiological state of the parent source. High nitrogen content of the donor plant and exposure to low temperature at meiosis reduces albinos and enhances the chance of green plant regeneration. Pre‐treatment (e.g. storing buds at 4–10 °C for 2–10 days) is needed in some species. This and other shock‐treatments promote embryogenic development. The culture medium is sometimes supplemented with plant extracts (e.g. coconut water, potato extract). To be useful for plant breeding, the haploid pollen plants are diplodized (by artificial doubling with 0.2% colchicines, or through somatic callus culture).