Construction of homozygous diploid potato through maternal haploid induction
Jinzhe Zhang, Jian Yin, Jiayi Luo, Dié Tang, Xijian Zhu, Jie Wang, Zhihong Liu, Pei Wang, Yu Zhong, Chenxu Liu, Canhui Li, Shaojiang Chen, Sanwen Huang
Abstract
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.