Association Between Seed Coat Luster and Water Imbibition In Black Beans (Phaseolus vulgaris L.).

Seed coat luster of common black beans (Phaseolus vulgaris L.) is an attribute that determines consumer acceptance.  Shiny and opaque seed coat luster is controlled by a single dominant gene that also influences pigment leaching, water uptake, and visual appearance of the canned product.  A recombinant inbred line (RIL) population was developed from cultivars Black Hawk (opaque seed) and Shiny Crow (shiny seed).  The RIL population segregated for seed coat luster and was used to evaluate association between seed coat luster and water uptake, pigment leaching and canning properties. Dry beans were weighed before and after soaking to determine percent change in weight due to water uptake. A scale of 1-5 was used to evaluate pigment leakage based on the color of soaked solution (1=no color, 5=most color).  The anthocyanin content of the soaking water in cyanidin-3-glucoside equivalents, mg/L was determined using the pH differential  AOAC Method 2005.02.  Water uptake ranged from 11 to 118% and cyanidin-3-glucoside pigment leakage ranged from 675-1350 mg/L among lines. Visual observance of seed and soaking solution ranged from 1 to 5 among entries.  A strong association was found between seed coat luster and all variables. This information will be used to compare lines for association between seed coat luster and canning properties to allow plant breeders to improve the visual appearance of the canned product.