Visual analysis of accession by trait interaction structure of agro-morphological traits of safflower (Carthamus tinctorius L.) using accession by trait (AT) biplot model

Safflower an ancient oilseed crop is known as one of the oldest crops grown under semi-arid regions. In this research, 100 safflower accessions were investigated in an alpha lattice scheme (10×10) with two replicates across two growing years. Some morphologic, agronomic, yield components and seed yield performance were measured. The accession by trait (AT) biplot model was fitted to understand the structure of AT interaction and explained 60 and 66% of observed variation for the first and second year, respectively. A nonagon was constructed in the first year, and accession 28 exhibited the superior performance height of the first capitulum, seed yield and harvest index, while an octagon was formed in the second year, and accession 28 indicated the best performance for plant height, height of the first capitulum, seed yield and harvest index. The arrow-view plots indicated positive associations between seed yield and harvest index in the both years. The perfect accession biplot indicated that accessions 30, 33, 39, 45 and 93 from Iran, accessions 72 and 83 from Canada, accession 58 from USA, and accession 28 from unknown origin were identified as the best perfect accessions. The perfect trait biplot showed that plant height and stem diameter were more desirable and had highest representative and discrimination potential for screening safflower accessions. Regarding the results of both years, it can be concluded that accessions 7 (from Iran), 28 (unknown origin) and 33 (from Iran) had good potential for seed yield across two years, so they are good candidates for further analysis in order to cultivar release process for semi-arid regions.