Responses to NaCl stress of Citrus aurantium, Citrange troyer and Poncirus trifoliata in callus cultures: assessment of characters for evaluating salt stress responses in citrus rootstocks [French]

摘要

The study of the impact of salinity (137 mM NaCl) on the ionic relations of callus of the rootstocks Poncirus trifoliata, Citrange troyer and Citrus aurantium reveals a reaction of common sensitivity to the three genotypes ( browning and reduction in growth, increase in content of Cl-, in parallel with reduction in the level of K+, cationic mineral charge Cc+, and [Cc+ - Cl-]) and some specific responses ( increase in content of Na+, [ Na + Cl], Na/(K + Na) and in anionic deficit DeltaA(-) in conjunction with the decrease in the levels of Mg2+, K/Na and K/(Na + Cl)). Characters involved in the common sensitivity response may be considered as criteria for evaluating the global behaviour of citrus rootstocks versus the salt stress. But the modifications in ionic relationships with the more specific reactions of callus may be considered as indicators for screening citrus rootstocks. These markers show, indeed, that C. troyer is more sensitive than C. aurantium ( moderately sensitive) and P. trifoliata ( moderately tolerant). Furthermore, the increase in the proline and sugar contents is only significant for Citrus aurantium and would be an indicator of the sensitivity of this rootstock's callus of its tolerance against saline stress.