Dry Beans and Pulses Production, Processing, and Nutrition. Группа авторов

Dry Beans and Pulses Production, Processing, and Nutrition - Группа авторов


Скачать книгу

      Source: Original images by author, K. A. Cichy.

      Iron biofortification has been a major bean breeding initiative since 2003, primarily implemented through the International Center for Tropical Agriculture in collaboration with various national programs. HarvestPlus set iron biofortification targets at increases of at least 22 mg/kg above locally consumed varieties (Andersson et al. 2017). To date, at least 60 high iron bean varieties have been released in over 12 countries in eastern and southern Africa and Latin America (Saltzman et al. 2017; Beebe 2020). Breeding progress has been made largely through phenotypic selection for increased levels of raw seed iron concentrations. The large variability for iron and zinc levels in dry bean germplasm has facilitated breeding progress. Screening of the CIAT core collection of 1072 bean lines of Mesoamerican, Andean, and mixed‐origin beans has revealed genetic variability for seed Fe and Zn concentrations ranging from 34 to 96 mg/kg and 21 to 60 mg/kg, respectively (Islam et al. 2002). Iron concentrations as high as 152 mg/kg have been reported for some bean genotypes from race Chile (Paredes et al. 2009).

       Organic dry beans

      Organic dry beans are a high‐value specialty crop of multiple market classes, including black, dark red kidney, and white kidney beans. Dry beans are an appealing option for organic farmers, since consumer demand is strong. The price premium for organic dry beans is 1.5–3 times that of conventionally produced beans. Controlling weeds and insect pests effectively without the use of pesticides is a major challenge for organic producers (Frick et al. 2017). Despite these constraints many larger producers continue to produce high‐quality organic beans but at resulting lower yields. In side‐by‐side studies over three years in Michigan, 36 bean varieties grown under organic production systems averaged 18% lower yields than under conventional systems (Heilig and Kelly 2012).

      Currently, organic producers use varieties developed for conventional production systems and some of these may not perform as well under organic production systems. Prior dry bean breeding research suggests that breeding under organic systems is more valuable in some market classes than others. Genetic variability for seed yield under organic vs. conventional showed that for black and navy beans the best lines under organic were also the best performers under conventional (Heilig and Kelly 2012). This is likely because of the goals of conventional breeding programs are beneficial for all producers. For example, traits such as disease or insect resistance, overall productivity, and improved plant architecture are valuable for both conventional and organic producers. Heilig and Kelly (2012) found that in the case of kidney beans the best lines under conventional were not necessarily the best under organic. Therefore, selecting kidney lines under organic conditions would be beneficial to improve germplasm for organic production. Breeding for organic production systems is underway in multiple public breeding programs around the US.

      Heirloom beans is another niche opportunity for bean breeders. Demand for heirloom and specialty beans is increasing, and this trend is due in part to direct‐to‐consumer bean sellers such as Rancho Gordo, that have effectively created demand by framing stories around the beans which appeal to consumers (King et al. 2021). Some popular heirloom beans include Jacob’s Cattle, Calypso, Soldier, and Hidatso Red. There is also interest on the part of breeders to improve heirloom beans for agronomic characteristics and disease resistance. Studies of the yield and SNF capacity of heirloom vs conventional showed comparable yields for some heirlooms and reductions for others suggesting they can be incorporated into parents in breeding programs without major yield drag (Swegarden et al. 2016; Wilker et al. 2019). Five improved heirlooms were recently released by UC Davis, including a Rio Zape and Tiger’s Eye. Each was improved by backcrossing with the I gene to add BCMV resistance while maintaining the heirloom seed types (Parker et al. 2021a,b,c,d,e).

      Genomic research

      The Phaseolus vulgaris genome sequence of the Andean landrace, Chacha Chuga (G19833) was released in 2014 (Schmutz et al. 2014); v2.1 is the most current version available, which has been updated with long read PacBio sequencing. The sequence is available at phytozome.jgi.doe.gov. Since the genome release, there has been a surplus of genomics research on beans. This research has aided in our understanding of genetic mechanisms for various traits, including better understanding pathogen response for anthracnose and common bacterial blight (Vaz Bisneta et al. 2020; Simons et al. 2021), drought stress (Diaz et al. 2020), and domestication related traits (Soltani et al. 2021), to name a few.

      Thus far, no commercially available bean varieties developed through genetic modification (GM) or through gene engineering are being marketed in the US. Beans have lagged behind soybeans


Скачать книгу