Seed development is a fundamental aspect of agricultural productivity, as seeds provide food, fuel, and livestock feed. The growing population and loss of arable land necessitates increasing agricultural productivity per acre. Understanding the factors influencing seed development is therefore an important target for agricultural research, and will prompt long-term improvements in farm productivity and profitability while protecting natural resources.Key observations link small RNA-directed DNA methylation (RdDM) with seed development in diverse species, yet direct evidence for this connection has been elusive. We recently demonstrated that Brassica rapa mutants lacking RdDM exhibit a severe reduction in seed production without other developmental phenotypes, offering clear evidence of the importance of RdDM during seed development. The significance of these B. rapa RdDM mutants cannot be overstated, since for the first time there is a tractable system to study the impact of RdDM on seed development.We have used the B. rapa RdDM-deficient mutant background for a genetic screen to uncover novel alleles that influence seed production and identified 10 suppressor mutants. The goal of the proposed work is to use classical genetics and modern sequencing technologies to characterize these suppressors before identifying the causal alleles. We anticipate that these suppressors impact genes that connect RdDM with seed development as well as alleles influencing RdDM-independent aspects of seed production. Because B. rapa is a close relative of canola (Brassica napus), favorable alleles can be rapidly incorporated into canola breeding programs to increase yield.