Breeding and cultivating method for early-matured, disease-resistant and loose purple cauliflowers

The invention relates to a breeding and cultivating method for a plant, in particular relates to a breeding and cultivating method for loose purple cauliflowers, and belongs to the technical field of plant cultivation. The breeding and cultivating method comprises the steps of hybridizing a loose purple cauliflower breeding material with a semi-compact purple cauliflower breeding material to obtain seeds F1, and selfing single strains with high comprehensive agronomic characters after the seeds F1 are sowed to obtain seeds F2; performing microspore culture on single loose purple cauliflowers through flower buds suitable for the microspore culture from the mononuclear edging stage to the double-core early stage to grow a large number of normal regenerated plants, selfing excellent DH plants of the loose purple cauliflowers to obtain a loose purple cauliflower excellent DH strain 03-12 serving as a recurrent parent which is hybridized with a cauliflower cytoplasmic male sterility source material CMS05-6, performing five generations of backcross transformation and selection to form a cytoplasmic male sterile line CMS08-2, and hybridizing the DH strain serving as a parent with the excellent cytoplasmic male sterile line CMS08-2.