Colchicine- and oryzalin-induced hexaploidy enhances nutrient levels and is a promising way to create new germplasms for Chinese chives

Chinese chives reproduce primarily through apomixis, which greatly limits hybrid breeding efforts. Herein, germinated triploid Chinese chive seeds were used as the materials, and colchicine and oryzalin were applied to induce chromosome doubling. Observations of the growth habits and analysis of several secondary metabolites were compared between triploid and hexaploid Chinese chives. Results indicated that both colchicine and oryzalin can cause shortening and thickening of the young roots and cotyledons, with a greater survival rate observed in seedlings treated with oryzalin than in those treated with colchicine. The leaf cellulose content in hexaploid seedlings was approximately 7.6 % lower than that in the leaves of triploid seedlings, while the soluble sugar, total flavonoid, vitamin C, soluble protein, and flavour compound contents increased by 110.5 %, 27.3 %, 10.2 %, 8.9 %, and 2.2 %, respectively. Our findings suggest that oryzalin is an effective chemical agent for inducing chromosome doubling in Chinese chives and that the induced hexaploid possesses greater edible value.