Tomato yellow leaf curl disease
CLN3241-coded F7:8 lines and inbred line checks ‘Tanya’ (susceptible),CLN2498D (Ty-2) and CLN3552B (Ty-3 and Ty-2) were screened in separate nethouse trials for resistance to ToLCTWV or Tomato yellow leaf curl Thailand virus–Taiwan strain (TYLCTHV[TW]). Plots of entries and checks comprised 12 plants and were arranged in a RCBD with two replications. Entries in the TYLCTHV[TW] and ToLCTWV trials were sown on 11 March and 24 March 2015, respectively. On 30 March, seedlings in the TYLCTHV trial were transferred to a nethouse containing plants of susceptible line CL5915-93D4-1-0-3 infected with TYLCTHV-[TW] and abundant viruliferous whiteflies. Similarly, on 10 April the seedlings in the ToLCTWV trial were transferred to a nethouse containing CL5915-93D4-1-0-3 plants infected with ToLCTWV and abundant viruliferous whiteflies. Every seven days after whitefly exposure, entries in both trials were scored for disease severity using a 1–6 severity scale, where: 1 = healthy, no observable symptoms; 2 = very mild with slight yellowing and mosaic on top leaves and no leaf curling; 3 = mild yellowing, mosaic and/or slight leaf curling on youngest leaves, severe symptoms; 4 = moderate yellowing and/or leaf curling on the youngest (top) leaves; 5 = severe yellowing and blistering and/or severe leaf curling plus some leaf size reduction on the youngest leaves of the main stem and/or at least one branch; 6 = very severe yellowing, blistering and/or very severe leaf curling, leaf deformation, leaf size reduction and stunting.