Scaling up Seed Production for the Restoration of Threatened Slickspot Peppergrass (Lepidium papilliferum)
Faculty Mentor Information
Dr. Sven Buerki, Boise State University; Peggy Martinez, Boise State University; and Dr. Ian Robertson, Boise State University
Presentation Date
7-16-2026
Abstract
Slickspot peppergrass (Lepidium papilliferum) is a federally threatened mustard endemic to southwestern Idaho’s sagebrush-steppe. While wildfires, urban development, and invasive weeds negatively impact populations, declines are still observed in protected areas. Thus, habitat preservation alone cannot shield this species from extinction, shifting our priority toward uncovering the biological mechanisms driving reproductive failure. We hypothesize that population bottlenecks drive genetic drift, causing random loss of diversity in alleles controlling reproduction. In a species governed by a self-incompatibility system—a genetic mechanism that blocks self-fertilization to maintain population diversity—loss of allelic diversity directly restricts seed production when compatible mates are scarce. To counteract this, we employ informed breeding to maximize reproductive success. Our initial approach involved bulking an initial plant cohort via growth chamber germination, greenhouse cultivation, and a four-week cold stratification to induce flowering. Mature plants were initially paired using a random mating approach. While this produced seeds, the yield was low because limited diversity increases the likelihood of matching individuals with identical alleles, which prevents a successful seed set. To resolve this efficiency bottleneck, we collected leaf tissue from the cohort for genomic sequencing. Future efforts will utilize the genomic data to perform informed, directed matings rather than random ones. By crossing individuals based on their genetic profiles, we aim to bypass the self-incompatibility barrier and produce healthy seeds for restoration.
Scaling up Seed Production for the Restoration of Threatened Slickspot Peppergrass (Lepidium papilliferum)
Slickspot peppergrass (Lepidium papilliferum) is a federally threatened mustard endemic to southwestern Idaho’s sagebrush-steppe. While wildfires, urban development, and invasive weeds negatively impact populations, declines are still observed in protected areas. Thus, habitat preservation alone cannot shield this species from extinction, shifting our priority toward uncovering the biological mechanisms driving reproductive failure. We hypothesize that population bottlenecks drive genetic drift, causing random loss of diversity in alleles controlling reproduction. In a species governed by a self-incompatibility system—a genetic mechanism that blocks self-fertilization to maintain population diversity—loss of allelic diversity directly restricts seed production when compatible mates are scarce. To counteract this, we employ informed breeding to maximize reproductive success. Our initial approach involved bulking an initial plant cohort via growth chamber germination, greenhouse cultivation, and a four-week cold stratification to induce flowering. Mature plants were initially paired using a random mating approach. While this produced seeds, the yield was low because limited diversity increases the likelihood of matching individuals with identical alleles, which prevents a successful seed set. To resolve this efficiency bottleneck, we collected leaf tissue from the cohort for genomic sequencing. Future efforts will utilize the genomic data to perform informed, directed matings rather than random ones. By crossing individuals based on their genetic profiles, we aim to bypass the self-incompatibility barrier and produce healthy seeds for restoration.