Assessing the Breeding Potential of Thirteen Day‐Neutral Landrace Accessions in an Upland Cotton Breeding Program

Abstract

ABSTRACTAn untapped genetic resource available to cotton (Gossypium hirsutum L.) breeding programs is represented by the primitive, upland cotton landrace collection. Primarily due to their photoperiodic nature, efforts to utilize these resources have been slow. To complement efforts to develop day‐neutral converted germplasm lines, we identified a number of naturally occurring day neutral landrace genotypes and evaluated their breeding potential when crossed to elite upland germplasm lines and cultivars. The mean performance of parental lines and F2 hybrids along with genetic effect estimates indicate that naturally occurring day‐neutral landrace genotypes provided average agronomic performance while increasing fiber quality performance. Results suggest that crosses derived from naturally occurring day‐neutral genotypes and elite upland lines result in new allelic combinations that interact in both an additive and nonadditive way. However, it appears that several naturally occurring day‐neutral genotypes transmit negatively correlated alleles for agronomic performance and fiber quality that often display opposite additive and nonadditive effects. These negatively correlated allele combinations present a major challenge for cotton breeding programs. Future efforts that determine the percentage of “new” alleles present in the landrace germplasm, along with innovative breeding methods focused on efficiently capturing beneficial alleles, are needed to expand the cotton genetic base.