‘티와이썬’은 농촌진흥청 국립원예특작과학원에서 육성한 토마토황화잎말림바이러스(Tomato yellow leaf curl virus, TYLCV) 저항성 품종이다. 모계로는 TYLCV에 저항성으로 알려진 자원 ‘08-9-59’를 도입, 세대진전하여 사용하였으며 부계로 사용한 ‘원예9002호’는 1997년 ‘트러스트’ x ‘모모타로 요쿠’ 교배조합에서 계통 분리하여 2002년까지 내병성 검정 및 계통 선발을 통해 육성하였다. 2010년 두 계통을 이용한 교배조합을 작성하였으며 2011년 내병성 분자마커 검정, 2012년 대만 AVRDC에서 담배가루이를 이용한 TYLCV 저항성 유묘검정을 실시하였다. 그 결과 TYLCV에 저항성이며 반신 위조병(Ve), 시듦병(I2, I3), 고구마뿌리혹선충(Rex), 세균성반점 병(Pto), 줄기마름병(Asc1), 토마토모자이크바이러스(ToMV)에 복합내병성으로 인정되어 ‘티와이썬’이라고 명명하였다. ‘티와 이썬’은 무한생장형에 과형은 원형이며 평균과중 240g 정도, 당도는 4.2°Brix 정도이다.
‘TY Sun’ is F1 hybrid cultivar resistant to tomato yellow leaf curl virus (TYLCV) and developed by the National Institute of Horticulture and Herbal Science, Rural Development Administration. As a maternal line, ‘08-9-59’, a resource known to have resistance to TYLCV, was used, and ‘Wonye 9002’ was used as a paternal line. ‘Wonye 9002’ was selected from the artificial cross between ‘Trust’ × ‘Yoku Momotaro’ in 1997, and disease resistance test and selection was continued until 2002. In 2010, artificial crosses between above two parental lines was made and TYLCV resistance tests were conducted among F1 progenies using molecular markers in 2011. Seedlings of F1 progenies were also tested for TYLCV resistance using white flies at AVRDC in 2012. The cultivar ‘TY Sun’ is resistant not only to TYLCV but to Verticilium wilt (Ve), Fusarium wilt (I2, I3), Root knot nematode (Rex), Bacterial speck (Pto), Alternaria stem canker (Asc1), and tomato mosaic virus (ToMV). 'TY Sun' is indeterminate growth type. The fruit has round shape with 240g of fruit weight and 4.2 °Brix of sugar content.