Phenotypic Plasticity of Vegetable Amaranth, Amaranthus tricolor L. under a Natural Climate

The plastic responses of fifteen Amaranthus tricolor L. cultivars to the natural climatic conditions across successive two years were investigated. The interactions between cultivars and climates showed significant effects on all variables examined. SAT-072 cultivar showed the lowest plasticity in both years. Principle component analysis revealed three components (PCs) associated with 67% of the total variation (PC1 = 36%, PC2 = 19%, PC3 = 12%). PC1 includes leaf color attribute a*(red pigment), and photosynthetic pigments (chlorophyll a, chlororphyll b, total chlorophyll), while PC2 accounts for leaf color attribute b* (yellow pigment), betacyanins, betaxanthins and betalains. Canonical discriminant analysis (CDA) was an effective method for clear separation or grouping of cultivars that may promote effective management and utilization in crop-breeding programmes. Overall, these findings suggest the necessity of further study to enrich amaranth cultivars with desirable traits.