Early, non-destructive evaluation of drought tolerance in soybean

PEIRONE, L.; PEREYRA IRUJO, G.A; CASTAGNADRO, A.P.; AGUIRREZÁBAL L.A.N

Toledo

Congreso; XXI reunión de la Sociedad Española de Fisiología Vegetal. XIV Congreso Hispano-Luso de Fisiología Vegetal; 2015

Sociedad Española de Fisiología Vegetal

Early, non-destructive evaluation of drought tolerance in soybean Peirone, L.1; Pereyra Irujo, G.1; Castagnaro Atilio2; Aguirrezábal, L.1*. 1Laboratorio de Fisiología Vegetal, Unidad Integrada Balcarce INTA-Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata. 2Estación Experimental Agroindustrial Obispo Colombres, Instituto de Tecnología Agroindustrial del Noroeste Argentino, Argentina. * laguirre@mdp.edu.ar Water stress is one of the most important environment factors that cause crop losses. Automatic phenotyping platforms have been developed for increasing throughput, as compared to manual phenotyping. There are, however, very few examples in which the results obtained with these platforms have been tested against field performance. The aims of this work were: i) to correlate the ranking of drought tolerance observed in an automatic phenotyping platform and those obtained in greenhouse and field trials, and ii) to evaluate which traits allow an early, fast and non-destructive prediction of such ranking.Two experiments were conducted in an environmentally controlled greenhouse using the GlyPh phenotyping platform. In the first experiment, seven soybean genotypes (five commercial varieties, one breeding line and one plant introduction) were grown in pots and evaluated under two water scenarios: well watered (WW) and water stress (WS). The WS treatment started at 41 days after sowing (DAS) and the experiment finished at 65 DAS. A large numbers of traits were evaluated before and after the onset of the WS. Drought susceptibility index (DSI) for final shoot dry weight and leaf area was calculated for each genotype and compared to the DSI for yield per plant of published greenhouse and field trials. A second experiment was carried out with two contrasting genotypes under several water regimes. In both experiments, the genotypic ranking based on the DSI of biomass accumulation and leaf area during vegetative period agreed with the ranking based on the DSI of yield from previous experiments, which confirms the usefulness of an automatic phenotyping platform for evaluating drought tolerance in soybean. Additionally, some traits evaluated earlier during the experiment also showed a significant linear relationship with the final drought tolerance values. These traits included shoot dry weight (estimated non-destructively through image analysis) and transpiration efficiency at 46 DAS (i.e. 6 days after the onset of WS) and transpiration efficiency at 21 DAS.In soybean, is well known that biomass accumulation is linearly related to seed number per plant, which is the main component of yield. Early, non-destructive measurement of these traits could increase the throughput of automatic phenotyping platforms, allowing the evaluation of more genotypes per year.Keywords: Glycine max, phenotyping, drought susceptibility index, transpiration efficiency.