Climbing bean breeding for disease resistance and grain quality traits

Abstract

Common bean (Phaseolus vulgaris) is grown in two growth types, bush and climbing beans. The latter are preferred in several regions in East and Southern African as well as in Latin America (dominant in Rwanda and Colombia), due to higher yields and resilience compared with bush type. Common bean productivity is reduced by several pests and diseases between them. Bean common mosaic virus (BCMV), which is the most common and destructive poty-virus affecting bean production worldwide, and anthracnose, caused by the fungus Colletotrichum lindemuthianum, can cause yield losses as high as 95% in susceptible cultivars. Further important traits in common bean are high micro mineral contents to alleviate malnutrition and grain quality traits such as the canning quality of bean varieties, which is important for farmers to access the processing market. In this study, new climbing bean populations were generated (coded ENF/CGA) to combine high seed iron (SdFe) and multiple diseases resistance. Double and triple crosses between parents with virus and anthracnose resistance, high SdFe, and good agronomic traits were employed. In trials in Darien and Popayan, lines were identified that combine BCMNV/BCMV and anthracnose resistance with seed yields above 4000 kg/ha. Phenotypic evaluations validated the usefulness of SNP markers tagging the genes bc-3 and I for BCMN and Co-3 for anthracnose as a selection tool for field resistance. These results show the genetic potential of the lines that are now being tested in target regions to be delivered to smallholder farmers.anthracnose, BCMV, common bean (Phaseolus vulgaris), grain quality traits, marker-assisted selection | INTRODUCTIONCommon bean (Phaseolus vulgaris L.) is the most important grain legume for direct human consumption (Broughton et al., 2003;Câmara et al., 2013), a staple crop in many tropical regions in East and Southern African as well as in Latin America. It is grown especially by poor smallholder farmers and a valuable component of their diets due to its high nutritional value, rich in protein, micro minerals (iron and zinc), and vitamins (folate) (Messina, 1999). The global production of dry beans has reached 32 million tons per year (FAO, 2017).

Genotype x environment interaction in the iron and zinc biofortification of common bean grains

“…The negative or low correlation between the contents of Fe and Zn in the grains with yield, as well as the low association between the contents of Fe and Zn in the grains, have also been reported by other authors, such as Phuke et al (2017). Good grain filling leads to high yield, likely with a diluting effect on grain Fe and Zn, causing opposite associations (Portilla et al 2022). However, greater knowledge is needed on factors that affect the accumulation of microminerals in grains, and cultivars should be tested in various environments to obtain good estimators of the degrees of association and to determine local adaptation for new biofortified varieties (Andrade et al 2013, Portilla et al 2022).…”

“…Good grain filling leads to high yield, likely with a diluting effect on grain Fe and Zn, causing opposite associations (Portilla et al 2022). However, greater knowledge is needed on factors that affect the accumulation of microminerals in grains, and cultivars should be tested in various environments to obtain good estimators of the degrees of association and to determine local adaptation for new biofortified varieties (Andrade et al 2013, Portilla et al 2022).…”

“…The concentrations of micronutrients Fe and Zn in the grain are influenced by environmental conditions and by genotype. Therefore, extensive knowledge will aid the development of improved cultivars that maintain higher concentrations of micronutrients in grains in adverse environments (Waters and Sankaran 2011, Stanton et al 2021, Portilla et al 2022.…”

Bean Common Mosaic Disease: Etiology, Resistance Resource, and Future Prospects

“…The most cost-effective method for controlling BCMV infections is breeding resistant cultivars [159][160][161][162][163]. Indeed, the dominant I gene and recessive genes have been extensively used to breed resistant varieties [164][165][166]. However, pyramiding all the resistance into one cultivar is extremely time-consuming.…”

Evaluation of Pinto Genotypes of Common Bean for Resistance to Anthracnose

“…Several biotic and abiotic stress factors limit the production of common bean (Binagwa et al 2021;Hamabwe et al 2023;Njobvu et al 2020;Portilla et al 2022;Siamasonta et al 2021). Anthracnose, caused by Colletotrichum lindemuthianum, is a major disease of common bean and can cause yield losses of up to 100% depending on varietal susceptibility and environmental conditions (Pastor-Corrales and Tu 1989).…”