Measuring the Breeding Value of Upland Cotton (Gossypium hirsutum, L.) Populations Designed for Drought Tolerance.

Water deficit stress is one of most important yield and fiber quality limitations for cotton grown in Texas. Plant breeders have identified potential traits that could enhance water use efficiency (WUE) in cotton, but incorporation of these traits into elite backgrounds is necessary. Five parents plus four progeny F3 populations were grown in a replicated and spaced nursery from which individual plants were selected. Seedcotton from each plant was ginned and its fiber measured with HVI. A portion of seed from each plant was screened in a high-throughput seedling drought assay to ascertain relative drought tolerance. Results indicated substantial transgressive segregation for lint percent and fiber qualities and significant differences among families for drought tolerance. These findings suggest drought tolerance can be incorporated into high-yielding backgrounds, but it is important for breeders to quantify drought tolerance throughout the breeding process.