Rice genotypes differing in salt tolerance I. Growth response and NaCl accumulation of whole plants and their corresponding callus cultures

Abstract

Two pairs of contrasting rice genotypes, each pair having similar general characteristics but with marked differences in whole plant salt tolerance, were compared in terms of growth response and NaCl accumulation of whole plants as well as their corresponding callus cultures. At the whole plant level, salt‐tolerant genotypes ‘Pokkali’ and ‘IR 29725–25–22–3‐3–3’ outperformed their respective salt‐sensitive counterparts, ‘Peta’ and ‘IR 5’, as measured by such tolerance indices as damage index, relative biomass and relative fresh weight/dry weight ratio. The salt‐tolerant genotypes generally had lower Na and Cl contents in the shoots than did the salt‐sensitive genotypes, indicating that reduced Na and/or Cl accumulation in the shoots can be used as a physiological index of salt tolerance in rice. No significant differences, however, were found between the contrasting genotypes either in growth response or NaCl accumulation in callus cultures, suggesting that there is no direct relationship between salt tolerance at the cellular level and the whole plant level.

Notes

Department of Agronomy, South China Agricultural University, Guangzhou 510642, China.