Physiological characterization of drought tolerance in groundnut (arachis hypogaea l.) phenotypes

GUZZO MC; MONTEOLIVA MI; SOAVE JH; SOAVE SJ; BUTELER MI; LUNA CM

Cordoba

Congreso; 9th Advances in Arachis through Genomics & Biotechnology; 2017

Peanut Research Community

Peanut (Arachis hypogeae L.) an important crop in Argentina, is carried out in almost all of their extension of rainfed fields, consequently its productivity is undergoes variations. One of the proposed management strategies in a breeding programme is the generation of more tolerant to drought stress genotypes, and this requires efficient screening techniques. Direct selection in field for quantitative traits, is difficult because uncontrollable environmental factors. One suggested approach is to add observations related with the knowledge of the physiological processes limiting crop production under stress. There are two main mechanisms related to drought tolerance: the antioxidant response, which counteract the oxidative stress, and the osmotic adjustment, which compensates the decrease in water potential of the tissues. The aim of this work was to reproduce the drought stress observed in the field, under controlled conditions and water supply in greenhouse; and to evaluate physiological parameters in peanut genotypes in order to make an initial assessment of the genetic variability in the response to this stress in the germplasm bank of Criadero El Carmen.Drought was performed by irrigation suspension (up to 15% soil water content) and controls were maintained at field capacity. In drought, a reduction in height and leaf area was observed; and increased greenness (SPAD) and proline. We also analyzed FRAP (indicator of total non-enzymatic antioxidant capacity) and malondialdehyde (indicator of membrane damage). The analysis of biochemical parameters allowed us to differentiate cultivars according to physiological key mechanisms related to tolerance to drought stress.