Graphic analysis of trait relations of safflower based on the genotype by trait (GT) biplot

The GT biplots are an excellent tool for visualizing genotype-by-trait data and revealing the interrelationships among traits. This study was conducted to (i) examine the performance of 18 safflower genotypes on the basis of multiple traits including days to flowering and maturity (DF and DM), plant height (PH), number of heads per plant (HP), number of seeds per head (SH), 1000-kernel weight (TKW), and seed yield (YLD) and (ii) determine the effects of different growing environments on trait relations. The genotype-by-trait (GT) biplot analysis was applied to data from the genotypes grown under cold (Sararood, Kermanshah) and warm (Shirvan-chardavol, Ilam) conditions for two years. Combined ANOVA showed that the main effects relative to year, location, genotype and their interactions were significant for most of the studied traits. Year-wise and combined GT-biplots indicated that the relationships among the studied traits were not consistent across environments, but they facilitated visual genotype comparisons and selection in each environment. The combined GT biplot displays 58.2 % of the information in the standardized data of the safflower genotypes for the agronomical traits. High positive correlations existed between TKW and SH, between DF and DM, and between HP and PH, as indicated by the acute angles between their vectors. Yield components had low correlations with YLD. Genotypes G15 (PI 613394), G17 (Sina variety), G2 (PI 209295) and G11 (PI 401478) had the largest PC1 positive scores, and were placed very close to seed yield (YLD).

کلیدواژه ها:

Carthamus tinctorius L. ، Multiple traits ، GT-biplot ، Rain-fed ، Genotype evaluation