Advancing Diploid Potato through Selfing

Advancing Diploid Potato through Selfing Most diploid potato plants are self-incompatible and will not set fruit on selfing, making the development of inbred lines difficult or impossible. Peterson et al. found self-fertile plants segregating within an F1 potato population then used a whole genome scan to observe the approach to homozygosity after three generations of selfing. Many unfruitful and weak plants had to be discarded in each generation resulting in more heterozygosity in the surviving population than expected based on predicted gene segregation. Pollen tube growth was observed in styles of both fertile and nonfertile plants ruling out the usual mechanism of self-incompatibility where pollen tube growth is arrested in styles of nonfertile plants. Inbred line development in diploid potato is limited to rare self-fertile genotypes that tolerate substantial inbreeding depression. 