Location: Genetic Improvement for Fruits & Vegetables Laboratory
Project Number: 8042-21000-305-015-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2022
End Date: Jul 31, 2025
Objective:
Diploid potato improvement has been a topic of research for many years. New discoveries relating to self-compatibility have piqued potato researchers’ interest in diploid potato improvement in both the public and private sectors. As part of the process for diploid potato improvement, primary dihaploids (referred herewith as dihaploids for simplicity) are critical links at moving the improved crop genetics from the tetraploid level to the diploid level. This proposal seeks to determine the field performance of 436 novel dihaploids which have been developed by the Cooperator at the University of Maine. The field performance will be evaluated at multiple locations across the potato growing regions of the US. The Cooperator has developed 436 dihaploid potato lines via the process of crossing a tetraploid named variety to a S. phureja haploid induction line. These dihaploids have been assessed to be diploid based on chloroplast counts and/or SNP array data, and their genetics should only be contributed by the tetraploid parent. Eight different tetraploid varieties, Atlantic, Caribou Russet, NY121, Castle Russet, Saginaw Chipper, Dakota Trailblazer, Lamoka, and Payette Russet, were the progenitors of the 436 ME dihaploids. In addition, the Cooperator will also obtain 61 Tier 1 female-fertile primary dihaploid lines that have been sequenced to 20x coverage as part of the USDA-SCRI Potato 2.0 project. In total, we anticipate being able to characterize the field performance of 497 primary dihaploid lines.
Approach:
Cooperator will provide tubers from the dihaploid germplasm. ARS will plant a replicated complete block design with 3 replicates. Each replicate will be a ten-hill plot planted at 10 inches spacing with a 3-foot alley between plots. Diploid (DD829-09, HH699-02, and HH1037-01) and tetraploid (Atlantic, Lamoka, and Caribou Russet) checks will be used. The diploid checks are breeding lines selected based on a yield study which identified top yielding diploid breeding lines from the Michigan State University diploid potato breeding program in 2020 and 2021. Data from the field trial will be collected throughout the 2023 growing season (emergence, vine vigor, and maturity), as well as during and after harvest (total yield, tuber size, tuber shape, skin and flesh color, and specific gravity). The data will be used to identify the best performing dihaploid lines to be used as parents in diploid potato improvement efforts at ARS and by university collaborators.
