The role of genotype and production environment in determining the cooking time of dry beans (Phaseolus vulgaris L.)

Authors: Cichy, Karen; Wiesinger, Jason; BERRY, MATTHEW - Michigan State University; NCHIMBI-MSOLLA, SUSAN - Sokoine University Of Agriculture; FOURIE, DEIDRE - Grain Crops Institute Of South Africa; Porch, Timothy - Tim; AMBECHEW, DANIEL - Tennessee State University; Miklas, Phillip - Phil

Submitted to: Legume Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2019
Publication Date: 8/20/2019
Citation: Cichy, K.A., Wiesinger, J.A., Berry, M., Nchimbi-Msolla, S., Fourie, D., Porch, T.G., Ambechew, D., Miklas, P.N. 2019. The role of genotype and production environment in determining the cooking time of dry beans (Phaseolus vulgaris L.). Legume Science. 1(1):e13. https://doi.org/10.1002/leg3.13.
DOI: https://doi.org/10.1002/leg3.13

Interpretive Summary: Dry bean (Phaseolus vulgaris L.) is a nutrient dense food rich in proteins and minerals. While a dietary staple in numerous regions, including Eastern and Southern Africa, greater utilization is limited by its long cooking time as compared to other staple foods. Wide genetic variability for cooking time has been documented for dry beans. The few studies that have examined the genetic control of this trait suggest it is highly heritable, and controlled by a handful of genes. Very little is known about the stability of the cooking time trait across environments encompassing diverse agro-ecological zones. Such information would be useful to plant breeders interested in developing fast cooking bean varieties. The objectives of this research were to assess the phenotypic stability of cooking time in dry bean germplasm and to characterize the role of genotype, environment and the genotype x environment interaction on the cooking time of dry beans. This study was conducted with fourteen dry bean genotypes grown across fifteen environments using two cooking methods 1) pre-soaked and 2) unsoaked prior to cooking. The cooking times of pre-soaked dry beans ranged from 16 to 156 min, with a mean of 86 min and unsoaked cooking times ranged from 77 to 381 min, with a mean of 113 min for the fourteen genotypes across the production environments. The heritability of pre-soaked cooking time was very high (98%) and moderately high for unsoaked cooking time (~60%). The genotypic cooking time patterns were stable across environments, suggesting the cooking time trait can be effectively incorporated into new varieties by conducting breeding trials in a few production environments.

Technical Abstract: Background: Dry bean (Phaseolus vulgaris L.) is a nutrient dense food rich in proteins and minerals. While a dietary staple in numerous regions, including Eastern and Southern Africa, greater utilization is limited by its long cooking time as compared to other staple foods. A five-fold genetic variability for cooking time has been identified for P. vulgaris, and to effectively incorporate the cooking time trait into bean breeding programs, knowledge of how genotypes behave across diverse environments is also essential. Fourteen bean genotypes were grown in fifteen environments (combinations of locations, years and treatments) and their cooking times were measured both pre-soaked and unsoaked. The genotypes were selected because they exhibit a range of cooking times within Andean market classes of major importance to consumers, including yellow, cranberry, light red kidney, red mottled and brown. The fifteen environments included locations in the U.S., the Caribbean and Eastern and Southern Africa that are used extensively for dry bean breeding. Results: The cooking times of pre-soaked dry beans ranged from 16 to 156 min, with a mean of 86 min and unsoaked cooking times ranged from 77 to 381 min, with a mean of 113 min for the fourteen genotypes across the production environments. The heritability of pre-soaked cooking time was very high (98%) and moderately high for unsoaked cooking time (~60%). The genotypic cooking time patterns were stable across environments, suggesting the cooking time trait can be effectively incorporated into new varieties by conducting breeding trials in a few production environments. There was a positive correlation between pre-soaked and unsoaked cooking times (r= 0.638, p< 0.0001) and two of the fastest cooking genotypes when pre-soaked were also the fastest unsoaked (G1, Cebo, yellow bean; and G4, G23086, cranberry bean). Conclusions: Given the sufficient genetic diversity found, limited crossover genotype by environment interactions and high heritability for cooking time, it is feasible to develop fast cooking dry bean varieties of potential broad value without the need for extensive testing across environments.