Radish is an important root vegetable in the world, and many cultivars have been developed with various molecular marker systems to identify these cultivars. Recently developed markers for radish cultivar identification require only 11 primer pairs, but they still use conventional PCR with different annealing temperatures and time-consuming gel electrophoresis. To improve the genotyping method, we applied touchdown PCR with 11 primers with M13 tails among 105 radish cultivars. Touchdown PCR successfully generated amplicons in all 11 M13-tailed primers with a condition of annealing temperature starting from 55℃, decreased by 1°C and 33 cycles at 53°C. The 11 M13-tailed primers followed by fragment analysis produced 71 amplicons, which produced more amplicons than gel electrophoresis that produced 23 amplicons. Especially, simple sequence repeats produced more amplicons, 12 on average, than the other marker types. The present study requires less effort and provides more accurate results compared to genotyping using gel electrophoresis. Besides, a database can be established using digitized genotyping results among radish cultivars.

INTRODUCTION
MATERIALS AND METHODS
    1. Plant material and DNA extraction
    2. The design of M13-tailed primers and touchdownPCR
    3. Fragment analysis and gel electrophoresis
RESULTS
    1. M13-tailed primers with the touchdown PCR
    2. Fragment analysis compared to conventional gelelectrophoresis
DISCUSSION
적 요
ACKNOWLEDGMENTS
REFERENCES

• Hyewon Yu(Department of Environmental Horticulture, Dankook University, Cheonan 31116, Republic of Korea) | 유혜원 (단국대학교 환경원예조경학과 환경원예학전공)
• Yunjeong Jeong(Department of Environmental Horticulture, Dankook University, Cheonan 31116, Republic of Korea) | 정윤정 (단국대학교 환경원예조경학과 환경원예학전공)
• Junho Lee(Vegetable Division, National Institute of Horticultural & Herbal Science, Rural Development Administration, Wanju 55365, Republic of Korea) | 이준호 (국립원예특작과학원 채소과)
• Wonbyoung Chae(Department of Environmental Horticulture, Dankook University, Cheonan 31116, Republic of Korea) | 채원병 (단국대학교 환경원예조경학과 환경원예학전공) Corresponding author