Evaluation of some tomato germplasm for resistance to Tomato yellow leaf curl virus (TYLCV) disease in Ghana

摘要

The importance of tomato in Ghana cannot be overemphasized. However, it is susceptible to numerous of pests and diseases, including viral disease for which the best control strategy is genetic resistance. Tomato leaf curl disease is reported to be widespread in Ghana causing severe yield losses. The disease, caused by a whitefly-transmitted geminivirus, is of economic importance and has become a recent problem on tomato farms in Ghana. Farmers ignorantly use pesticides to control the TYLCV disease but to no avail. The best way to combat this disease is to use plants that are resistant to the disease. Consequently, the objective of this study was to screen 15 germplasm (with reported resistance to TYLCV) available from the AVRDC (The World VegetableCenter in Taiwan and CSIR-Crops Research Institute in Kumasi, Ghana). The germplasm, including known checks, were first challenged in greenhouse where they were planted in a complete randomized design (CRD) with four replications. The tomato plants wereexposed to whiteflies infected with tomato leaf curl disease. Scoring was then done when plants were 30 days, 45 days and 60 days after inoculations. These were repeated on a disease hot spot in the field for further evaluation. They were in randomized complete block design (RCB) with three replications. Scoring was done when plants were 30 days, 45 days and 60 days after transplanting. Other horticultural characteristics were also taken. There was no significant difference between accessions in terms of their ability to resist the disease. However, tomato accessions Al, A2 and A3 showed mild symptoms of TYLCV infection. Other lines also have lesser incidence and severity of TYLCV than the control and could be used in incorporating TYLCV resistance inbreeding work.