ABSTRACT
By the methods of principal component analysis, subordinate function, and cluster analysis, a comprehensive evaluation was conducted on the drought-resistance of 16 physiological indices of nine marigold cultivars. Under drought stress, the 16 physiological indices had different responses, among which, free proline (Pro), H2O2, and ascorbate peroxidase (APX) showed the greatest sensitivity. There existed significant correlations in the drought-resistance coefficients of parts of the physiological indices. Four principal factors presented 88.6% of the information of the 16 indices, and the cultivars 'Janie' and 'Gate gold', 'Bonanzn', 'Janie', and 'Chokdee' had the strongest drought-resistance for the 4 principal factors, respectively. The comprehensive evaluation value of the drought-resistance of the 9 cultivars was in the order of 'Janie' > 'Gate gold' > 'Bonanza' > 'Chokdee' > 'Giant' > 'Great hero' > 'Little hero' > 'Durango' > 'Discovery'. The 9 cultivars could be clustered into 3 groups, and 'Gate gold', 'Janie', 'Bonanza' and 'Chokdee' belonged to the drought-resistance group.
