NaCl胁迫对牡丹花石榴植株体内Na^+、K^+含量的影响

Effect of NaCl Tolerance on Contents of Na^+ and K^+ of Mudanhua Pomegranate Plants

以2年生牡丹花石榴为供试材料,研究NaCl胁迫对石榴枝、根韧皮部和木质部的Na+、K+含量及K+/Na+值的影响。结果表明:随着土壤中NaCl含量的增加,石榴植株枝、根的Na+含量整体呈增加趋势;K+含量呈先增加后降低趋势,NaCl含量为0.4%时,K+含量最高。相同NaCl处理下石榴枝的Na+、K+含量高于根部,而同一枝、根部位韧皮部的Na+、K+含量高于木质部(NaCl 0.5%、0.6%处理的K+含量除外)。低度盐胁迫(NaCl 0~0.4%)下K+/Na+值较大;而高度盐胁迫(NaCl 0.5%、0.6%)下K+/Na+值降低,且小于1。土壤中NaCl含量为0~0.4%时,牡丹花石榴可正常生长,过高则出现叶片黄化、落叶、生长不良的现象。

Two years old Mudanhua pomegranate seedlings were used as materials.The change of Na^＋ and K^＋ contents and K^＋/Na^＋ ratios in phloem and xylem of branch and root of pomegranate plants under salt stress.The results showed the contents of Na^＋ increased with the increase of NaCl concentration in soil;the contents of K^＋ first increased and then decreased,when the NaCl concentration reached 0.4%,the contents of K^＋ reached the peak value.The contents of Na^＋and K^＋were higher in branches than that in roots,the contents of Na^＋ and K^＋ were higher in phloem than that in xylem except the K^＋ content under 0.5% and 0.6% NaCl stress.The K^＋/Na^＋ ratios were higher under hyposaline conditions（NaCl concentration of 0-0.4%）than that under hypersaline conditions（NaCl concentration of 0.5%-0.6%）,and the K^＋/Na^＋ ratios were less than one under hypersaline conditions（NaCl concentration of 0.5%-0.6%）.Mudanhua pomegranate growed normally when the NaCl concentration was below 0.4% in soil,and high NaCl contents could cause leaf blade yellowing and falling,and negative growth.