%0 Journal Article
%T Efeito do Ca2+ externo no conte¨²do de Na+e K+ em cajueiros expostos a salinidade Effect of external Ca2+ in the Na+ and K+ content in cashew exposed to salinity
%A Dermeval A. Furtado
%A Francisco A. L. Alves
%A S¨¦rgio L. Ferreira-Silva
%A Joaquim A. G. da Silveira
%J Revista Brasileira de Ci¨ºncias Agr¨¢rias
%D 2011
%I Universidade Federal Rural de Pernambuco
%R 10.5039/agraria.v6i4a1257
%X Objetivando avaliar o efeito do Ca2+ externo na absor  o e transporte de Na+ e K+ em plantulas de cajueiro an o precoce, expostas a altos n¨ªveis de NaCl, sementes do clone de cajueiro, CCP 06, foram germinadas e cultivadas em vermiculita dentro de casa de vegeta  o. Plantulas com aproximadamente 8 folhas foram transferidas para condi  es controladas de temperatura a 25¡À2 ¡ãC, U.R 80%, fotoper¨ªodo de 12 h e 240 ¦Ìmol m-2 s-1, onde elas foram divididas em dois ensaios. No primeiro as ra¨ªzes foram destacadas da parte a¨¦rea e imersas em solu  es de NaCl (0; 100; 200; 300; 400 mM) + CaCl2 (0,0; 0,3; 5,0 mM). No segundo ensaio plantulas intactas foram imersas em solu  es de NaCl (0; 200 mM) + CaCl2 (0; 3 mM). As plantulas permaneceram nas solu  es acima por um per¨ªodo de 48 horas. O NaCl aumentou a absor  o e ac¨²mulo de Na+ nos diversos ¨®rg o das plantulas, al¨¦m de reduzir o conte¨²do de K+ nas ra¨ªzes e caules. A presen a de Ca2+ externo no meio contendo NaCl aumentou ainda mais a absor  o e ac¨²mulo de Na+ nos diversos ¨®rg os das mudas e tamb¨¦m manteve o conte¨²do de K+ nos ¨®rg os ao n¨ªvel de tratamentos controles. O efeito do Ca2+ no aumento da absor  o e transporte de Na+ permanece desconhecida. No entanto, esse efeito em plantulas de cajueiro submetidas a altas doses de NaCl est¨¢ bem evidente. To evaluate the effect of external Ca2+ on Na+ and K+ absorption and transport in dwarf cashew seedlings exposed to high levels of NaCl, seeds of the cashew clone, CCP 06, were germinated and grown in vermiculite inside a greenhouse. Seedlings with about 8 leaves were transferred to controlled temperature conditions at 25¡À2¡ãC, RH 80%, 12 h photoperiod and 240 ¦Ìmol m-2 s-1, where they were divided into two trials. In the first one, the roots were detached from the shoot and immersed into NaCl solutions (0; 100; 200; 300; 400 mM) + CaCl2 (0.0; 0.3; 5.0 mM). In the second trial, intact seedlings were immersed in NaCl solutions (0; 200 mM) + CaCl2 (0; 3 mM). The seedlings remained in the solutions above for 48 hours period. The NaCl increased the Na+ absorption and accumulation in different organs of the seedlings and reduced the K+ content in the roots and stems. The presence of external Ca2+ in the environment with NaCl increased even more the Na+ absorption and accumulation in different organs of the seedlings and it also retained the K+ content in the organs at the level of the control treatments. The effect of Ca2+ in increasing the Na+ absorption and transport remains unknown. However, this effect on cashew plants seedlings exposed to high doses of NaCl is very evident
%K Anacardium occidentale L
%K estresse salino
%K rela  o K+/Na+
%K Anacardium occidentale
%K salt stress
%K K+/Na+ relation
%U http://www.agraria.pro.br/sistema/index.php?journal=agraria&page=article&op=view&path%5B%5D=agraria_v6i4a1257