High productivity of dry pea genotypes resistant to crenate broomrape in Mediterranean environments

The cultivation of dry pea (Pisum sativum) is strongly hampered in Mediterranean and Middle Eastern farming systems by the parasitic weed Orobanche crenata. Resistant cultivars are not available to farmers, and only incomplete levels of resistance have been identified in landraces or wild relatives. Dry pea genotypes that combine the resistance of wild genotypes with good agronomic traits have been the focus of our breeding program. The objectives of this study were to evaluate the level and stability of resistance to O. crenata and the yield of these genotypes in different locations across the Mediterranean Basin and to identify the most useful environments in which to select for these traits. The responses to O. crenata and yield of pea genotypes were evaluated at five locations in Spain, Tunisia, and Egypt. Observed differences in both traits were due to the effect of genotype, environment, and environment × genotype interactions. A heritability-adjusted genotype plus genotype × environment interaction identified two mega-environments: the first, formed by the environments located in Egypt and the second, formed by the remaining environments. Breeding genotypes J26 and J26-2 showed good and stable yield and resistance responses to O. crenata in all environments. By contrast, J3 had a markedly different pattern depending on the mega-environment. It was one of the most resistant genotypes in the second mega-environment, but the most susceptible one in the Egyptian mega-environment. Both locations in Egypt were useful for selecting high yield and resistance to O. crenata, while, in the second mega-environment, Córdoba was the most useful in which to select for the traits. This study is the first to report advanced dry pea breeding genotypes that show resistance to O. crenata and high productivity in different environments. These genotypes will be highly useful in environmentally sustainable control of broomrape.SF was funded by the Ramón and Cajal program from the Spanish Ministry of Economy and Competitiveness. This work was supported by the Spanish Ministry of Economy and Competitiveness (AGL2014-52871R) co-financed by FEDER.Peer reviewe