Developing improved bush bean varieties in Ecuadorian market classes using farmer participatory crop improvement methods and marker-assisted selection of an anthracnose resistance gene

Bush beans are an important cash and subsistence crop in the Mira and Chota River Valleys of northern Ecuador. This project was undertaken to introduce genetic resistance to anthracnose into bean market classes grown in this region, and to determine the bean production practices, problems and variety preferences of bean producers in the Mira and Chota Valleys.;Co-42, a gene conferring broad-based resistance to anthracnose (Colletotrichum lindemuthianum) was introduced into bush bean varieties from three Ecuadorian commercial classes using marker assisted backcrossing. Anthracnose resistant lines were developed in two of the market classes but the Co-42 gene failed to function in the genetic background of two of the Ecuadorian varieties used as recurrent parents. Verification of disease reaction through direct inoculation is essential to support the use of marker assisted selection in resistance breeding.;Farmer surveys revealed that bean producers in northern Ecuador are switching to bean types with a domestic market after losing the bean export market to Colombia. Major production constraints are bean rust, whitefly, bean weevil, anthracnose, and root attacking pests and diseases. Few bean growers maintain their own seed but rather rely on the local grain markets as a source of bean seed. This system of seed management may be incompatible with the introduction of improved bean varieties in Ecuador.