| dc.description.abstract | Occurrence of Tomato yellow leaf curl virus has been increasing in Uganda since 1999. Fourteen tomato genotypes were screened for their performance under TYLCV infection in field and screen-house trials. Foreign genotypes from South Korea included Asya 616, Rhino, Calliope, Tygo, Eureka, Vega, Zodiac, Pruna, Tenten and Pinktop and the checks (farmer preferred) genotypes were MT56, Tengeru 97, Red cherry and Yellow cherry. These genotypes included determinate, semi-determinate and indeterminate types.
The study was conducted at NaCRRI, Namulonge from December 2018 - May 2019. Three trials were set up: in the field (natural infection), screen-house (inoculation using infector plant placement) and the control (greenhouse (un-inoculated). Field and screen-house experiments were replicated 3 times in a CRBD and CRD designs respectively, but there was no replication for the control. Each treatment had 20 plants; 10 of these were tagged for data collection. Data collected included: TYLCV severity (0 - 4 scale), agronomic traits (height, width and days to first flowering); and yield. Data collection started 30 days after transplanting in the field and 2 weeks after inoculation in the screen-house; and was collected 4 times at 15 - day intervals.
Tengeru 97 showed mild TYLCD symptoms (score 1 and 10% disease incidence). Significant differences (P < 0.05) in symptom severity occurred between genotypes. Pruna recorded maximum height in the field (86.6) and screen-house (82.6), Tenten in the greenhouse (121.0). There was no great variability in plant width among genotypes although Vega, Tengeru 97, Zodiac and Pruna were wider than others. Screen-house tomatoes flowered earliest followed by greenhouse and lastly field tomatoes; there was, however, no significant difference in time to flowering among tomato varieties in the screen-house. Genotypes with the earliest days to flowering especially in the field where, MT56 (51), Red cherry (51) and Yellow cherry (51) although they also yielded poorest. Generally, tomatoes from the control experiment performed best.
Foreign tomato genotypes seemed to be resistant to TYLCV and performed better than farmer preferred genotypes in terms of yield and other agronomic traits. Genotypes such as Vega, Asya 616 and Calliope that performed best are recommended for use in tomato breeding programs to increase tomato yields and enhance TYLCV resistance in Uganda. | en_US |
