Breeding for resistance to chocolate spot in faba bean

Abstract

Among the different fungal diseases that affect faba bean, chocolate spot incited by Botrytis fabae is one of the most important, causing in many cases significant yield reductions, being particularly damaging when high relative humidity and mild temperatures concur. Control by fungicides is possible, but it is not environmentally and economically efficient. The employment of resistant varieties appears as the best option. In the last years we have developed a comprehensive breeding program with the main objective of obtaining cultivars combining resistance to chocolate spot and adaptation to Mediterranean environments. This included screening large germplasm collections both in seedlings under controlled conditions and in adult plants in the field over a series of seasons and locations. Identified resistances were introduced in our breeding program and progenies selected for combined resistance and productivity. As a result of this process, now we have available a set of advanced breeding materials. A cultivar has already been submitted for registration and some more are in the offing. In addition to these applied breeding activities we are approaching genetic studies and have developed a recombinant inbred line (RIL) population that has been properly phenotyped over several seasons and genotyped using DArT-Sea marke rs to identify quantitative traits loci (QTLs) related to resistance. These results will be presented and critically discussed.