Evaluation of the germ plasm collection of safflower, Carthamus tinctorius L. V. Distribution and regional divergence for morphological characters

For many centuries, safflower, Carthamus tinctorius L., was grown for the dye extracted from its flowers and as a minor oilseed crop. Only in recent decades has it become an oilseed crop of importance in some areas. In the traditional mode of cultivation, in small plots, there were many small populations in which various selection pressures could operate. The world germ plasm collection of safflower with nearly 2000 lines originating in about 30 countries, was evaluated for divergence by studying the distributions of various expressions (states) of 13 morphological characters (descriptors). The traits were: late rosette leaves' margin; upper stem leaves' margin, shape and color; branches' location and angle; primary head shape; outer involucral bracts' cross section, attitude, spines' length, number and location; corolla color. Divergence due to human and/or natural selection was found for some of the traits and ten centers of cultivation were designated. Geographical sources for desirable traits were identified.