An in planta haploid induction system in Brassica napus

Doubled haploid technology is widely used to accelerate plant breeding, but its use in the important oilseed crop Brassica napus L. is limited because B. napus haploids could only be obtained through in vitro anther or microspore cultures. Recently, maize (Zea mays) lines containing mutations in Domain of unknown function 679 membrane protein (DMP) were used as haploid inducer lines. This new haploid induction mechanism has been extended to several other plants, including the dicots Arabidopsis thaliana, tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum). Here, we knocked out four BnaDMP genes in the B. napus cultivar Westar using a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 vector with an enhanced green fluorescent protein expression cassette. Plants with DMP mutations in B. napus in the T-0, T-1, and T-2 generations exhibited a haploid induction rate up to 2.53%. These results suggest that targeting BnaDMP could be useful for haploid induction in B. napus.

Automated summary

Doubled haploid technology is commonly used in plant breeding, but its application in Brassica napus L., an important oilseed crop, has been limited due to difficulties in obtaining haploids. However, recent research has shown that knocking out DMP genes can induce haploids in B. napus. The study found that B. napus plants with DMP mutations exhibited a high haploid induction rate across multiple generations.