Ancestral landraces of common bean from the South of Europe and their agronomical value for breeding programs
Selection among breeding lines has been widely used to identify important cultivars and favorable alleles for adaptation, and resistance to abiotic and biotic stress. The objective of this work was to study the variability among common bean breeding lines selected from ancestral landraces, to evaluate the reaction of these lines to anthracnose (ANT) rust, common bacterial blight (CBB), halo bacterial blight (HBB) and bean common mosaic virus (BCMV) and to study the introgression in ancestral landraces of Phaseolus vulgaris L. Fifty-five breeding lines obtained by individual selection, 21 parents or ancestral landraces and six check cultivars were grown in four environments. Thirty morphological and agronomical traits, the reaction to five diseases, and allozyme and phaseolin profiles were determined. Significant differences among breeding lines were recorded for morphological and agronomical traits. The lines 0330-02, 0452-03, 0219-06, 0323-01, 0323-13, and 0323-15 would be useful genetic material to use in breeding programs for increasing seed yield. Thirty-six breeding lines were tolerant or resistant to different diseases. The lines 0221-14 and 0452-03 are worthy of special mention because they had resistance to four diseases. Allozyme and phaseolin pattern studies indicated a predominance of Andean genetic material but 14 breeding lines presented intermediate characteristics between both Andean and Mesoamerican gene pools and may represent unique genetic recombination events. These genotypes could be of utility to breeders seeking to improve common bean. This work indicates the existence of lines with superior characteristics and favorable alleles that merit further evaluation in genetic studies.