Breeding method for virus-free potato minituber

The invention relates to the technical field of agriculture and particularly relates to a breeding method for a virus-free potato minituber. The breeding method for the virus-free potato minituber comprises the steps that an aseptic seedling is put by cottage in a seedbed containing an induction medium for cultivation; the seedbed needs to be thoroughly watered before cottage, and cultivation of 20-26 h is conducted under a dark condition after the cottage, wherein a temperature is controlled between 18 DEG-21 DEG C, and a relative humidity is kept between 95% and 100%; after fixed planting for 7-20 days, a nutrient solution is sprayed for 4-6 times according to seedling conditions, the medium is kept moist during growth of a new seedling, and a water-holding capacity is within 60%-70%; and after fixed planting and seedling recovery of a virus-free seedling, additional application of additional carbon dioxide gas fertilizer is started when leaves grow to a growth-age size; and a plantcan be recovered when one