sEvaluation of processing tomato cultivars for resistance against Tomato yellow leaf curl Thailand virus and high yield production

Tomato yellow leaf curl Thailand virus (TYLCTHV), which is caused by whitefly-transmitted begomoviruses, is very destructive and causes heavy losses in tomato yields, especially in sub-tropical and tropical regions including Thailand. This research aimed at evaluating the yields of 28 tomato cultivars and their resistance to TYLCV. The cultivars used were collected from the Plant Breeding Center for Sustainable Agriculture at the Faculty of Agriculture of Khon Kaen University in Thailand. The study was conducted under drip irrigation at the Vegetable Research Station of the Department of Horticulture, Faculty of Agriculture at Khon Kaen University during the period of October 2019 to February 2020. Screening against TYLCTHV was carried out under both induced natural disease conditions and whitefly mediated inoculation, with symptoms that ranged from symptomless to very severe infections. The study indicated that four cultivars showed the highest yields plant^‑1, and these consisted of ‘KKU-T278’, ‘KKU-T193’, ‘KKU-T233’, and ‘KKU-T204’ (3,265.7, 3,135.1, 2,926.3, and 2,898.2 g, respectively). Under the natural disease conditions, five cultivars appeared symptomless until the fruit maturation stage. The results for resistance were classified into 2 groups based on their responses to TYLCTHV. The first group (i.e., ‘KKU-T224’, ‘KKU-T249’, and ‘KKU-T276’) were identified as being ‘Resistant’ (R); while, the second group (i.e., ‘KKU-T245’ and ‘KKU-T233’) were identified as having a ‘High resistance’ (HR).