In a greenhouse study, the sensitivity of 12 cotton genotypes was evaluated against the Fusarium wilt disease. The genotypes showed considerable variation in Fusarium-wilt resistance (0.83 to 80.25%). The genotypes could be divided into four groups, i.e. highly resistant, moderately resistant, moderately susceptible and highly susceptible. The HPLC analysis of amino acid cotton genotype seeds revealed the presence of 17 amino acids, but their occurrence in seeds varied with genotype. None of the individual amino acids was significantly correlated with resistance to Fusarium wilt. Data for resistance rating and concentrations of amino acids were submitted to stepwise-multiple regression statistical analysis. Using the predictors supplied by stepwise regression, an eight-factor model was constructed to predict the Fusariumwilt resistance. The model showed that differences in Fusarium-wilt resistance were associated with the 8 amino acids (isoleucine, valine, proline, phenylalanine, lysine, histidine, tyrosine, and cysteine), which accounted for 100% variation in resistance. Thus amino acids composition of cottonseed may provide a supplementary assay to greenhouse tests to quantitatively distinguish between the Fusarium-wilt resistant and susceptible genotypes.
Biomarkers, fusarium-wilt, genotypes, gossypium barbadense, resistance, seeds, susceptibl
