Registration of CA 4008 cotton germplasm line

Abstract

AbstractEnhancing genetic diversity to breed cotton (Gossypium hirsutum L.) for water‐limited production in the Texas High Plains is one objective of the Texas A&M AgriLife Research breeding program in Lubbock. CA 4008 (Reg. no. GP‐1099, PI 698821) was derived from TX 307 (PI 165390) and 07‐A‐05, an unreleased breeding line. TX 307, wild material of species Gossypium hirsutum, was used as a parent based on performance in hydroponic salinity characterization of 290 accessions conducted at Texas A&M AgriLife Research in Lubbock from 2006 to 2009. Performance testing for yield, fiber quality, and other agronomic properties was conducted at six site‐years from 2014 to 2017 with check cultivars ‘FM 958’ (PI 619096), a high‐yield and fiber quality regional standard, and ‘DP 491’ (PI 618609), which historically produced good yield and quality under water stress in the Texas High Plains. CA 4008 produced similar yield and fiber quality, lower lint percentage, and taller plants across site‐years compared with checks. CA 4008 was tested at 11 locations across the United States in the 2017 Regional Breeder Testing Network and showed low leaf defoliation under Verticillium wilt pressure. In previous studies, CA 4008 had less germination reduction under salinity than 27 of 31 Texas A&M AgriLife Research in Lubbock lines but equal to cultivar ‘FM 989’ (PI 603956). CA 4008 had less root dry weight reduction under salinity in hydroponic studies but equal to FM 989 in shoot and leaves dry weight reduction. CA 4008 is adapted to Texas High Plains stress conditions developed from a wild accession.