Fig. 3. Principal component (PC) analysis projections on axes 1 and 2. (a) Eigenvalues are presented as vectors for the following traits: contribution of preanthesis assimilates to the grain by the spike (C_S), flag leaf blade (C_FB), flag leaf sheath (C_FS), other leaf blades (C_L), and stem (C_ST), final grain weight (W_G), dry weight of the spike (W_S), flag leaf blade (W_FB), flag leaf sheath (W_FS), other leaf blades (W_L), and stem (W_ST), days from sowing to anthesis (DSA), relative main stem weight with regard to total aboveground plant biomass (%MS), and grain yield per hectare. (b) Values of the cultivars are symbolized by their period and country: old Italian (OI), intermediate Italian (II), modern Italian (MI), old Spanish (OS), intermediate Spanish (IS), and modern Spanish (MS).