Improving adaptation to drought stress in small red common bean: phenotypic differences and predicted genotypic effects on grain yield, yield components and harvest index

Abstract

Common bean (Phaseolus vulagaris L.) is mainly produced in Latin America, and Eastern and Southern Africa where seasonal rainfall is erratic and soil moisture deficit often limits its production. The objectives of this study were to identify superior advanced small red common bean lines with better grain yield under drought, and to identify plant traits that could serve as selection criteria for evaluating drought resistance. Thirty four advanced inbred lines were developed through triple cross and evaluated with two commercial checks (Nasir and Red Wolayita) under drought and irrigated field conditions in two seasons (2009 and 2010) and at two locations (Melkassa and Doni Kumbi Farm) in Ethiopia. Grain yield, pods/plant, seeds/plant and 100 seed weight were reduced by 47, 19, 15, and 9 %, respectively, under the drought conditions compared to the irrigated conditions. Seven genotypes (L62, L5, L20, L79, L12, L41, and L83) had better yield under drought compared to the standard check. Similarly, these genotypes had better predicted genotypic effects, suggesting that they would also be useful as drought resistant donors in common bean cultivar development program. Genotypic variance expressed as proportions to phenotypic variance was higher compared to genotype 9 environment interaction effects for all traits under drought conditions, suggesting that these genotypes can be used to further improve drought-resistance regardless of environments. Strong correlation between grain yield, canopy biomass and harvest index across environments suggested that canopy biomass and harvest index are repeatable and reliable plant traits to determine drought resistance in common bean.

Shoot and Root Traits Contribute to Drought Resistance in Recombinant Inbred Lines of MD 23–24 × SEA 5 of Common Bean

“…Drought stress is known to reduce yield components such as PNA and SNA (Rao et al, 2013; Assefa et al, 2015). Seed number per pod has been identified as useful criteria for selection for improving drought resistance because of its higher heritability and contribution to genetic gain (Ramirez-Vallejo and Kelly, 1998).…”

Improving adaptation to drought stress in white pea bean (Phaseolus vulgaris L.): Genotypic effects on grain yield, yield components and pod harvest index

“…We observed that drought‐tolerant lines in this study had relatively bigger seed sizes (SW values greater than 18 g) compared to the standard check (Awash‐1). This might be due to better seed filling that improved seed size and also improved seed quality (Assefa et al., ; Beebe et al., ). Besides contributing to GY, greater SW values could also be an advantage since bigger‐sized seeds have better canning quality and cooking time than the small‐sized seeds.…”

“…Efficient remobilization of photosynthate or greater partitioning of dry matter to grain yield has been emphasized as an important drought tolerance mechanism in common bean (Assefa et al., ; Beebe et al., ; Klaedtke et al., ). Recently, Polania et al.…”

“…Grain yield (GY) is the most dependable measurement of drought tolerance in common bean (Assefa et al, 2015;Ramirez-Vallejo & Kelly, 1998;Rao et al, 2013). Drought stress can cause yield reduction ranging from 22% to 71% in common bean (Ramirez-Vallejo & Kelly, 1998).…”

“…Bean cultivars that combine high values of canopy biomass with greater mobilization of photosynthates to grain were identified as drought-tolerant cultivars (Polania et al, 2016;Rao et al, 2013). Drought-tolerant genotypes that produce greater biomass accumulation under waterlimited conditions produce more grain yield compared to droughtsensitive genotypes (Assefa et al, 2015;Polania et al, 2016).…”