SEED GOSSYPOL VARIATION WITHIN GOSSYPIUM-BARBADENSE L COTTON

Gossypol, a triterpenoid aldehyde found in all species of the genus Go ssypium, possesses insecticidal, antimicrobial, antifertility, and ant itumor properties. Gossypol content in cotton seed varies among cultiv ated species and among cultivars within species. This investigation wa s conducted at the Texas Agricultural Research Center in San Angelo, T X, in 1993 to determine the regional and geographic variability for se ed gossypol content and isomer form in G. barbadense L. A set of 57 ac cessions (collected during 50 yr from 21 countries) representing five regions, and 26 cultivars were analyzed. Species' variation for gossyp ol and isomer content exceeded previous reports. Total gossypol conten t in seed ranged from 3.0 to 34.0 g kg(-1) kernel weight. The more bio logically active negative isomer ranged from 249 to 689 g kg(-1) total seed gossypol. Cotton accessions collected west of the Andes mountain s in South America displayed the greatest variation in seed gossypol a nd gossypol isomer contents. Accessions from Central America and Argen tina displayed the least variation. Subsets of accessions, possessing unique levels of seed gossypol or gossypol isomer, were identified wit hin regional groups or cultivars. A low (r = 0.02) phenotypic correlat ion between gossypol content and isomer ratio suggested that simultane ous selection for the two traits is feasible.