Development of a New Molecular Marker for the Resistance to Tomato Yellow Leaf Curl Virus

Figure 1

Disease characterization in commercial hybrid varieties and in F2 population derived from commercial resistant AG208 F₁ hybrid. (a) Five-week-old asymptomatic resistant tomato seedling of AG208 hybrid. (b) Susceptible symptomatic tomato seedling of Hi-tech1. (c) Flowering stage of resistant tomato plants. (d) Susceptible tomato plants. (e) PCR-based diagnostic performed using TYLCY390 primer pair on DNA from tomato plants at flowering stage. (f) Resistant F1 plants form AG208. (g) Upper leaves of resistant F1 plants form AG208. (h-i) Plant upper leaves of F2 individual with 0 DSL. (j-k) Plant upper leaves of F2 individual with 1 DSL. (l-m) Plant upper leaves of F2 individual with 2 DSL. (n-o) Plant upper leaves of F2 individual with 3 DSL. (p-q) Plant upper leaves of F2 individual with 4 DSL. (r) Segregation of ACY marker in F2 population; DSL: disease symptom level, 0: no symptoms, 1: slight symptoms visible upon close inspection, 2: clear symptoms evident on a portion of the plant, 3: heavy symptoms on entire plant, and 4: severe symptoms and stunting of entire plant. The plants belonging to scales 0, 1, and 2 were considered resistant, while 3 and 4 were susceptible. Resistance fragment = 132bp and susceptible fragment = 123bp.