LAUSR

Crop breeding schemes can be significantly accelerated by using (doubled) haploid plants. In vivo haploid induction has been applied in plant breeding since decades, but is still not available for all crops, genotypes and haploidization rates are generally very low. Therefore, methodological improvements and new concepts to haploidization are required. Here, we report a novel system for the induction of haploid plants by mutating genes encoding egg cell-specific aspartic endopeptidases (ECSs). We show that after successful sperm-egg cell fusion, ECSs play a critical role to ensure male and female nucleus fusion after fertilization. The ecs1 ecs2 double mutant can induce haploids by both selfing and hybridization, and is capable to produce haploids in both Arabidopsis and rice. In summary, we report a novel approach for maternal haploidization and additionally provide new insights into the molecular basis of fertilization.