Jeonnam-Gwangju Agricultural Research and Extension Services develops disease-resistant, low-cracking jujube-shaped cherry tomato

In greenhouse tomato cultivation, tomato yellow leaf curl virus (TYLCV) and tomato spotted wilt virus (TSWV) are considered devastating diseases that, once they occur, are difficult to control and have a major impact on farm yields. In fact, in a nationwide survey of crop virus disease incidence conducted by the Rural Development Administration in 2023, tomato yellow leaf curl virus was detected at 14% of all tomato farms. If fruit cracking caused by changes in irrigation volume and temperature is added to this, yields may be produced, but the volume that can be sold as marketable produce decreases. This is why growers have continued to demand varieties that combine disease resistance and resistance to fruit cracking.

The Horticultural Research Institute of the Jeonnam-Gwangju Integrated Special City Agricultural Research and Extension Services has bred a jujube-shaped cherry tomato line targeting these conditions and will begin the application process for plant variety protection. The institute set cultivation stability as its goal from the development stage. Park Min-young, a researcher at the Horticultural Research Institute who led the development, said, “The goal was to obtain a variety that is less prone to cracking, has high disease resistance, and also has excellent sugar content and firmness.”

47.3 fruits per cluster and 3,326 kg per 10a… 28.8% more than the control variety

The newly bred “JCT22020” line has combined disease resistance (possessing disease-resistance genes) against TYLCV and TSWV as well as late blight and wilt disease. It also has short internode length, making cultivation management easier, and was found to have less fruit cracking caused by changes in the cultivation environment (visually compared with Betatini without measurement).

Productivity indicators were also secured. According to the institute’s productivity test results, the number of fruits set per cluster was 47.3, more than double that of the control variety Betatini (22.8), and marketable yield per 10a (about 300 pyeong) was 3,326 kg, 28.8% higher than Betatini (2,582 kg). These figures were achieved while maintaining an average fruit weight of 20.7 g and an average sugar content of 9.4 Brix (°Bx).

Trial cultivation was conducted from 2024 to 2025 at the institute’s experimental field in Naju, Jeonnam-Gwangju Integrated Special City. One characteristic test and two productivity tests were carried out, and evaluations were conducted up to the sixth flower cluster.

Researcher Park said, “It is a variety that resulted from selecting, combining, and crossbreeding traits such as disease resistance, high sugar content, high firmness, and low cracking during the segregation and selection process.” This is a method of selecting and crossing lines that each have target traits such as disease resistance, flavor, and fruit texture. Park explained that combined disease resistance and high sugar content and firmness were expressed together in this line.

Higher firmness than the control variety and slightly higher sugar content… Marketability rate of 85.6% remains a challenge

In the productivity test, JCT22020 was found to have higher firmness than Betatini and a slightly higher sugar content. Based on the autumn growing season, JCT22020 recorded firmness of 6.27 N and sugar content of 10.1 Brix, while Betatini recorded firmness of 5.49 N and sugar content of 9.92 Brix. The acidity of JCT22020 was 1.01%, higher than Betatini’s 0.78%, indicating that the trait was fixed in a direction that balances acidity and sugar content rather than emphasizing sweetness alone.

However, the marketability rate was 85.6%, 9.1 percentage points lower than Betatini’s 94.7%. Researcher Park said, “As the number of fruits set per cluster and total yield have increased, managing quality variation among individual fruits remains a challenge at the cultivation stage.”

In blind tasting evaluation, harmony of sweetness and acidity was the most common response at 38%

In a blind tasting evaluation conducted by video conference (Zoom) on July 31, 2026, 50 consumer panelists participated using a multiple-response format. For JCT22020, the most common opinion, at 38%, was that it had a good harmony of sweetness and acidity. This was followed by responses that the size and shape were appropriate or uniform at 34%, that the texture was good at 22%, and that it was rich in juice at 20%.

The high evaluation for size and uniformity aligns with the consumer preference trends confirmed in the same survey. Respondents preferred a size that was easy to eat in one bite, and for samples with large fruits, they also pointed out that they were burdensome to eat in one bite. The jujube-shaped standard with an average fruit weight of 20.7 g falls within this range.

In addition, cherry tomatoes distributed on the vine were fresh, but preference for them was low because of the hassle of picking them off one by one and washing them. As for fruit color, red and yellow were preferred, while greenish fruit tended to be avoided because it was perceived as unripe.

Among negative responses, 14% said the taste was bland or the sugar content was weak, 10% said the skin was tough, and 8% said the flavor was unfamiliar or the aroma was unpleasant.

Farmers will be able to actually obtain seeds after the plant variety protection registration is completed. The process is structured so that seed companies begin seed production and sales after the application and examination. Researcher Park expected that seeds would be available for purchase through companies one to two years after the application.