Identification and multi-environment validation of resistance against broomrapes (Orobanche crenata and Orobanche foetida) in faba bean (Vicia faba)

• No complete resistance against Orobanche crenata or O. foetida has been identified in faba bean germplasm.
• Genotype × environment interaction revealed instability of the phenotypic expression across environments.
• Accessions have been identified showing significant levels of resistance that was stable across environments.
• Accessions resistant to both O. crenata and O. foetida have been identified.

Broomrapes are weedy root parasitic plants that severely constrain faba bean (Vicia faba) production. The most widely distributed species affecting faba bean is Orobanche crenata, although O. foetida is of local importance in Tunisia. After long and extensive breeding efforts made in several countries only moderately resistant cultivars are available to farmers. In an attempt to identify new sources of resistance a germplasm collection of 483 V. faba accessions was screened for resistance to O. crenata under field conditions in Córdoba, Spain. Stability of resistance of the 37 most resistant accessions was further tested in a multi-location experiment in Egypt, Tunisia and Spain over three field seasons. Resistance to O. foetida was also tested in Tunisia.Although complete resistance was not found, and in spite of significant genotype × environment interaction revealing instability of the phenotypic expression across environments, this study allowed the identification of a number of accessions showing significant levels of resistance that was stable across environments. Cultivar Baraca and accessions V-1268, V-1302, V-1301, V-268, V-231, V-319 and V-1272 were the most resistant and stable across environments, and what is most interesting, being resistant both to O. crenata and O. foetida.