Seed curvature as a useful marker to transfer morphologic, agronomic, chemical and sensory traist from Ganxet common bean (PHaseolus vulgaris L.)

Abstract

The Ganxet bean is a highly appreciated landrace characterized by markedly curved seeds, high protein content, low seed-coat perceptibility, and low mealiness. To analyze the genetic control of seed curvature and of morphological, agronomical, chemical, and sensory traits related to high quality in these beans, we used an Additive, Dominance, and Additive × Additive model applied to Ganxet and Faba Asturiana varieties, their F1, F2, BC1P1, and BC1P2 progenies.

The narrow-sense heritability (h2) of seed curvature was 0.72. The h2 of the number of seeds per pod was 0.75. The h2 of area and length of the seed were 0.55 and 0.60, respectively. The h2 for seed width, 100-seed weight, pod length, Mg content, and sensory traits mealiness, seed-coat roughness and seed-coat perceptibility, ranged from 0.3 to 0.4. Seed curvature behaved like a continuously variable trait that is probably controlled by 3 loci. The expression of this trait depends partly on the environment, and its expression is greatest in environments that favor larger seeds. Seed curvature also had strong additive genetic correlations with protein content (positive) and with mealiness (negative).

Given the ease of determining seed curvature and its apparently simple control, this trait could be used as an easy-to-select morphological marker to transfer high protein content and low mealiness to other varieties by backcross procedures, regardless of whether the correlation between traits is due to pleiotropic or linkage effects.