|Rayburn Jr, Samuel|
|Smith, C - TX A&M COLLEGE STATION|
|Calhoun, M - TX A&M SAN ANGELO|
Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: June 1, 2000
Publication Date: N/A
Technical Abstract: Gossypol's toxic properties in cotton seed ave been a deterrent to its use as a feed to animals. Gossypol consists of 2 optical isomers, designated "plus" and "minus". The minus isomer is the more biologically active of the 2 isomers. The objective of this study was to sample the National Cotton Variety Test to determine if sufficient genetic variability exists within current varieties to warrant further investigations. The Regional High Quality (RHQ) study was selected as it has historically showed much genetic variability for many traits. Two of its 1998 locations, Stoneville, MS and College Station, TX wee chosen as sites to evaluate 20 varieties. At 3 of the locations of the National Pima Variety Tests, 2 varieties' seed was also evaluated. Location difference for total gossypol, plus and minus were large. The RHQ variety variance component was large. The percent of total, plus and minus gossypol accounted for by the variety effect was 61,72 and 53%, respectively. The variety X location component accounted for 9, 6, and 12%, respectively, of the total variance components. Of major interest was the minus % of total gossypol. Its variety component was 92, and its interaction component was 3% of the total variance components. These results show large amounts of genetic variation for plus and minus gossypol within Upland varieties and advanced breeding differences among 3 varieties. The minus content of Pima cotton is high.