Phenotypic differences in adaptation to combined stress of inadequate P supply and drought (BASE 80 trial)

Abstract

A field trial was conducted during the dry season (May to July 2016) at Darien, Valle del Cauca-Colombia, The BASE (Bean Abiotic Stress Evaluation). The BASE trial included 80 bean genotypes: 58 belong to Mesoamerican gene pool, 11 to Andean gene pool and 11 interspecific lines. An 8 X 10 alpha lattice design with 3 replicates was used. The soil is an Andisol with inadequate level of P supply (available P content (Bray-II) of 7 mg/kg). One level of water supply (Rainfed) was applied to induce drought stress. Experimental units consisted of 2 rows of 2.5 m long with 0.6 m between rows. A number of plant attributes were measured at mid-pod filling including root traits using shovelomics methodology (basal root whorl number; basal root number; adventitious root number; tap root branching density; 3rd order branching density; and minimum, maximum and mean basal root growth angle), SPAD chlorophyll meter readings (SCMR), canopy temperature depression (CTD), and canopy biomass per area. At the time of harvest, grain yield and yield components were determined. Pod partitioning index, pod number per area, seed number per area, and pod harvest were also determined.