NaCl胁迫下石榴和桃植株Na^＋,K^＋含量与耐盐性的研究

Study on Contents of Sodium and Potassium Ions of Pomegranate and Peach Plants under Sodium Chloride Stress and Thire Salt Tolerrance

石榴和桃是两种耐盐性不同的果树。前者在含盐（ＮａＣｌ，以下同）０．３％土壤上植株Ｎａ＋含量有少量增加，含盐量达０．４％时才大量增加；后者在含盐０．２％的土壤上Ｎａ＋含量增加不多，含盐０．３％土壤上急剧增加。盐处理明显增加植株Ｋ＋含量，Ｋ＋／Ｎａ＋增加。植株Ｋ＋／Ｎａ＋值，石榴平均约为桃的１．５倍，死亡植株Ｋ＋／Ｎａ＋值小于１。ＲＰＸＫＮａ、ＲＳＫＮａ及ＳＸＰＫＭＡ值表明，Ｎａ＋、Ｋ＋经过石榴根系时，Ｎａ＋被韧皮部细胞积累，Ｋ＋优先进入木质部，Ｎａ＋、Ｋ＋从根系向枝条运输时及从枝条木质部向韧皮部转运时，Ｎａ＋被木质部再吸收，Ｋ＋优先向地上部及枝条韧皮部积累。桃对Ｎａ＋、Ｋ＋的选择吸收运输能力较石榴弱。

The previous paper had suggested that pomegranate could grow in the soils with 0.3% salt contents and peach below 0.2% salt contents. This Paper showed that sodium ion contents in POmegranate plants increased in small amount under 0.3% NaCl treatment, and rised considerably when the soil salt contents high up to 0.4%. However, sodium ion contents of Peach plants increased dramatically in 0.3 % salt content soils. NaCl treatments increased potasssium contents in both fruit tree plants, thus K+/ Na+ ratios were higher in treated plants than controls and that in pomegranate plants were averagely 1.5 times as high as in peach plants. The K+/ Na+ ratios of dead plants of both species were not higher than 1. RPXKNa, RSKNa and SXPKNa values showed that in pomegranate plants Na+ were accumulated by root phloem, K+ preferentially entered xylem, and xylem cells reabsorbed Na+ in that K+ were selected upto shoots and its phloem. Peach plants were poor selective in K-Na.