All major grain legumes, including cowpea, peanut, and pea, have been genetically transformed, and beans continue to resist transformation using Agrobacterium. This has been a formidable hurdle, and one that was bypassed by colleagues in Brazil who have successfully transformed beans using a particle gun (Bonfim et al. 2007). This was the first use of RNA interference technology to achieve this remarkable result of engineered Gemini Virus resistance to Bean Golden Mosaic Virus in the field (Aragão and Feria 2009), which has since been moved into commercial “carioca bean” cultivars (Souza et al. 2018). These varieties were engineered to express resistance to the Gemini Virus pathogen Bean Golden Mosaic Virus. This was the first use of RNA interference technology to achieve this remarkable result of engineered Gemini virus resistance in the field (Aragão and Feria 2009).
The cost to deregulate GM beans in the US is estimated at over $10 million for each GM event but the revenue generated by the crop across diverse states and seed and pod types is insufficient to support deregulation. This bodes well for consumers who are “anti‐GMO foods” or for European markets that similarly continue to exclude GM products. The downside is that bean producers cannot avail themselves of the same production technologies as soybean producers, which will result in a competitive loss of bean acreage in many production states. Lower acreage will undoubtedly result in smaller crop production and higher prices to the consumer. This fact alone is concerning, given the new evidence of the valuable health benefits of increasing bean consumption in the US diet to help combat obesity, diabetes, and certain cancers (Thompson et al. 2009). The US bean industry with limited research support needs to address this question in a rational and reasonable fashion using science‐based research. Breeders are consistently asked to make progress and compete with GM crops such as soybean, yet they are limited in the tools they can use to address future production needs and challenges. Perhaps CRISPR (Zaidi et al. 2020) will provide an affordable consumer‐accepted gene‐editing technology to engineer improved traits for common bean in the near future.
FUTURE DIRECTIONS
Greater focus on climate change and sustainable production will be key breeding goals of the future. Global climate changes underscore the strong justification for continuous public breeding efforts to preserve bean yield potential through breeding of improved resistance to rapidly evolving biotic and abiotic stresses and the continued displacement of bean production to less favorable environments across the globe.
A 2010 study demonstrated the importance of maintenance breeding as it relates to climate. It was found the 15% reductions in present‐day yield of IR8, the miracle rice variety developed over 50 years ago resulted from the lack of adaptation to current environmental conditions (Peng et al. 2010). The authors stressed the critical role that breeding plays in improving the adaptation of newly developed varieties to changing climatic conditions that have a negative impact on older varieties. The same holds true for bean breeding.
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