Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 236

As a consequence of inbreeding during tomato domestication, the genetic diversity in cultivated tomato is now very narrow. However, large variation is present and exploitable in the wild Solanum species. Thus, the first step was to find wild tomato accessions with resistance to tomato powdery mildew.

At the Tomato Genetics Resource Center in Davis, California (TGRC, http://tgrc.ucdavis.edu) and Botanical and Experimental Garden (http://www.bgard.science.ru.nl) in the Netherlands, thousands of accessions of the wild Solanum species have been collected and maintained. From these collections, we have selected and tested some Solanum species with tomato powdery mildew. As expected, many wild accessions showed resistance (Figure B5.1).

Figure B5.1 Tomato plants inoculated with tomato powdery mildew. (a) The left plant is from tomato wild species Solanum pervianum LA2172, showing no powdery mildew infection; the right plant is from S. lycoerpsicum cv. Moneymaker (MM), showing fungal clonies growing on infected leaves. (b) A closer look at the colonization of tomato powdery mildew (Oidium neolycopersici) growing on the upper‐side of MM leaf. Pictures were taken 15 days post inoculation.