Analysis of canonical correlation of physiological traits with phonological and root traits in different bread wheat genotypes

To estimate the relationships and correlations among different traits in wheat, 30 bread wheat genotypes were studied in two separate experiments in greenhouse and field under two conditions (non-stress and drought stress at the beginning of flowering stage). The experimental design in both greenhouse and field conditions was a split plot design in which drought stress and wheat genotype were considered as the main- and sub-factor, respectively, but the basic design in the greenhouse was completely randomized design and in the field was randomized complete block design both with three replications. The results of canonical correlation analysis showed that there was a significant correlation under both non-stress and drought stress conditions between pairs of canonical variables resulting from physiological traits with root and phenological traits, so that in the field conditions, the first canonical function for physiological traits (V1) was most affected by number of days to 50% flowering and grain filling rate, but for phonological traits (W1) by catalase (CAT), peroxidase (POX), malondialdehyde (MDA), leaf H2O2 and proline contents. In contrast under greenhouse conditions, the first canonical function for root traits (V1) was more affected by proline, leaf H2O2, MDA, POX, CAT, total chlorophyll and chlorophyll-a contents, while for physiological traits (W1) by root dry weight. The results of this experiment showed that to select drought tolerant cultivars under both non-stress and drought stress conditions, increasing root dry weight by increasing MDA concentration, leaf H2O2 content, proline content, POX and CAT and decreasing total chlorophyll and chlorophyll-a under greenhouse conditions and increasing grain filling rate by increasing CAT, POX and proline and decreasing MDA and H2O2 under field conditions can be considered as appropriate selection criteria.