Using Colchicine to Create Poinsettia (Euphorbia pulcherrima × Euphorbia cornastra) Mutants with Various Morphological Traits

Commercially available novel cultivars of poinsettia, obtained through interspecific hybridization, were subject to colchicine-based mutagenesis to recover their fertility, enabling subsequent breeding. Mutagenic treatment was conducted at different concentrations of colchicine with either lanolin or cotton serving as the matrix. The results indicated that 1 day was the optimal duration of colchicine treatment and that suitable colchicine concentration varied by cultivar. Moreover, one-time treatment gave higher rates of both polyploidy and morphological mutant production than two-times treatment. Specifically, the poinsettia cultivars Dulce Rosa (5 mg·g−1 colchicine with lanolin; 10 mg·mL−1 colchicine with cotton) and Princettia-Hot Pink (15 mg·g−1 colchicine with lanolin; 10 mg·mL−1 colchicine with cotton) yielded relatively high polyploidy production efficiency and morphological mutation rate. Consequently, a total of three polyploidy mutants of ‘Dulce Rosa’ and 19 polyploidy mutants of ‘Princettia-Hot Pink’ were obtained. Both cultivars had mutants with recovered fertility, with pollen germination rate of up to 27.5%. Moreover, unexpected non-polyploidy mutants with various morphological trait variations were also obtained.

Inheritance of Leaf Tip Shape and Fringed Leaf Margin in Sunflower

After mutagenic treatment of sunflower seeds two traits of altered leaf shape were found – obtuse shape of leaf tip and strongly sinuate (fringed) leaf margin. To study the inheritance pattern of these traits, the mutant lines were crossed with the source lines and between themselves. It was shown that the traits of obtuse leaf and fringed leaf are recessive and inherited as monogenic traits when mating with the source line. In crossings of mutants, all F