2026 Focused Seed Grant
Awardee
Sven Sierra
Master’s Student, Plant Breeding and Genetics
University of Wisconsin-Madison
Faculty Advisor
Rajdeep Khangura
Assistant Professor
University of Wisconsin-Madison
Project Collaborator
Gurcharn Singh Brar
Assistant Professor, Wheat Breeding and Genetics
University of Alberta
Abstract
Lr34 is a durable source of resistance to biotrophic fungal diseases in wheat. It’s expression can vary across genetic backgrounds as it interacts with other known and unknown leaf and stem rust resistance genes. Studies have uncovered dominant modifiers that enhance or suppress Lr34 mediated resistance. Markers to select these modifier loci can maximize the resistance potential of Lr34. Using a dominant male sterility system, I propose a scalable approach to discover Lr34-dependent modifier loci using genome-wide association study in F1 hybrids. The assembled wheat panel will permit screening these modifiers in modern cultivars, develop effective molecular markers, and eventually, help develop improved lines by selecting alleles that enhance Lr34’s effectiveness against leaf rust, stem rust, and stripe rust. By project end, the near-isogenic lines in select cultivars will be ready to test across geographies and make crosses to advanced lines in breeding programs.
About Sven Sierra
Sven is a master’s student in the Plant Breeding and Plant Genetics Program at the University of Wisconsin-Madison, where he conducts research in the Cereal Genetics Lab under the supervision of Dr. Rajdeep Khangura. His research background extends into plant pathology, small fruit breeding, and bioinformatics. He currently focuses on gene mapping and development of hybrid systems in wheat. Sven has developed a simple hybridization protocol using triflamide, a chemical hybridization agent, and is exploring other scalable hybrid systems through genetic male-sterile mutants. Further work leverages these hybrid systems to explore novel mapping strategies in wheat. Recognizing that the performance of disease resistance can vary across different genetic backgrounds, Sven’s project selected by the 2026 BGRI-GWHA Translational Wheat Health Seed Grant aims to address this concern by identifying and deploying enhancer genetic elements that strengthen Lr34-mediated resistance, contributing to more effective race non-specific rust resistance in wheat.
“By further developing scalable hybrid wheat systems, I hope to explore genetic mapping methods new to wheat, expanding the genetic toolbox available for researchers, and generate advanced breeding material for plant breeders. I aspire to combat the major global crop diseases that threaten food security and cause substantial economic losses, while advancing the frontiers of wheat genetics and hybrid systems.”
Sven Sierra
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