Canning quality improvement in navy beans: genetic, environmental and compositional factors

Navy bean (Phaseolus vulgaris L.) provides important raw materials for the bean canning industry. This article reviews grain compositional aspects influencing the canning and quality attributes of canned navy beans and breeding methodologies and strategies used to develop genotypes with superior canning-quality traits. Cultivars that are destined for the bean canning industry should meet the set canning-quality standards regardless of their yield potential. A number of phenotypic quality parameters are used to predict the final canning quality of genotypes. Primary quality parameters mainly comprise washed drained weight, processing quality index, and texture. Phenotyping for these traits is very expensive and requires grain quantities that can only be obtained in the advanced filial generations, making it difficult to breed for. Molecular marker-assisted selection has not yet contributed much to the improvement of canning quality in navy beans. However, it has the potential to facilitate the genetic improvement of several canning-quality traits. The review paper concludes with a number of recommendations. There exists a need for harmonizing protocols and standards for canning quality by breeders and processors, development and release of navy bean cultivars that combine high grain Fe and Zn content and drought tolerance with good canning qualities, and evaluation of genotypes across a number of environments. A need exists to identify stable and specifically adapted genotypes with respect to canning quality and drought tolerance, hasten the identification of molecular markers that are linked to canning-quality traits; and mainstream demand-led breeding in breeding programs to satisfy the market requirements.