Physiological and biochemical responses of peanut genotypes to water deficit

Abstract

The effects of drought on water relations, gas exchanges, solutes accumulation, and catalase (CAT), ascorbato peroxidase (APX), and guaiacol peroxidase (GPX) activities were studied in five Arachis genotypes, grown under control or withholding water conditions. Drought stress reduced plant growth of all genotypes; the genotypes A. duranensis 7988 and A. stenosperma SV2411 being characterized as the most drought-sensitive and A. ipaensis as the most drought-tolerant. Data of transpiration and stomatal conductance confirmed the findings that A. ipaensis was more tolerant to drought conditions. Water deficit increased organic solutes content and reduced leaf water potential in all genotypes. The data suggest that solutes accumulation in roots may, at least in part, explain the greater tolerance of A. ipaensis to drought stress. CAT activity showed a significant increase in stressed leaves of sensitive genotypes. APX and GPX activities either increased or were not affected by drought in leaves of all genotypes. © 2010 Taylor & Francis.