earticle

영어

Yuja(Citrus junos) is good at cold and skin care, and has prevention effect on fatigue and aging. It is used as extract, tea, vinegar and etc. But its fruits are very seedy. Tetraploid seedlings were firstly induced by colchicine treatment to development of seedless new variety for processing industry. And leaf thickness was compared between diploid and tetraploid seedlings to development new more efficient ploidy testing method. Yuja seeds were immersed at 0.2% colchicine solution up to 48 hours and in 0～0.4% colchicine solution for 24 hours, but there were no difference among treatments. So, it is considered colchicine is not effective in tetraploid induction of yuja seeds. Leaf thickness was measured using a micrometer in order to find a new efficient method for discrimination of tetraploid among a lot of seedlings. The diploid and tetraploid leaf thicknesses were different at 0.19 ± 0.02 mm and 0.23 ± 0.03 mm, respectively. Seedlings its leaf thickness was more thicker than 0.23 mm, was all tetraploid. In addition, the tetraploid roots were characterized by small number, short and thick. The roots of diploids have occasionally the same shape, but leaf thickness is thinner than tetraploid. Therefore, it is possible to be sure that the seedlings with thick leaves, small number of roots, short and thick roots are tetraploid.