Chlorophyll content of tomato yellow leaf curl virus-infected tomatoes in relation to virus resistance

A good association was found between chlorophyll content of TYLCV-infected tomato lines and individual F₂ plants, and their TYLCV resistance which was evaluated visually. Moreover, by examining the resistance of the F₃ progeny it was demonstrated that determination of chlorophyll content provided an earlier and more precise quantitative evaluation of resistance than visual evaluation. The chlorophyll test is simple and useful for studying virus-vector-plant interactions and estimating TYLCV resistance in extensive breeding programs.