Construction of homozygous diploid potato through maternal haploid induction

Reinventing the tetraploid potato into a seed-propagated,diploid,hybrid potato would significantly accelerate potato breeding.In this regard,the development of highly homozygous inbred lines is a prerequisite for breeding hybrid potatoes,but self-incompatibility and inbreeding depression present challenges for developing pure inbred lines.To resolve this impediment,we developed a doubled haploid(DH)technology,based on mutagenesis of the potato DOMAIN OF UNKNOWN FUNCTION 679 membrane protein(StDMP)gene.Here,we show that a deficiency in StDMP allows the generation of maternal haploids for generating diploid potato lines.An exercisable protocol,involving hybridization,fluorescent marker screening,molecular and flow cytometric identification,and doubling with colchicine generates nearly 100%homozygous diploid potato lines.This dmp-triggered haploid induction(HI)system greatly shortens the breeding process and offers a robust method for generating diploid potato inbred lines with high purity.