碱茅离子吸收与分配特性研究

Studies on the Characteristics of Ion Absorption and Distribution in Puccinellia Tenuiflora

本文报道了大田拔节期和完熟期碱茅根系对土壤中Ｎａ＋、Ｋ＋的选择性吸收（ＳＡ）及植株各部位间Ｎａ＋、Ｋ＋的选择性运输（ＳＴ）能力，并对Ｎａ＋、Ｋ＋、Ｃａ２＋、Ｍｇ２＋、Ｃｌ－在植株各部位中的分布特性进行了研究。结果表明，完熟期碱茅的ＳＡ值是其拔节期的１．５倍，表明前者根系拒排Ｎａ＋、吸收Ｋ＋的能力强于后者；拔节期和完熟期碱茅ＳＴ２（根系：茎）值均较高，说明根系控制Ｎａ＋、促进Ｋ＋向茎部运输的能力很强，拔节期碱茅ＳＴ３（茎：叶鞘）值较低，茎对Ｎａ＋、Ｋ＋的选择性运输能力很弱，拔节期碱茅ＳＴ４（叶鞘：叶片）值介于ＳＴ１值与ＳＴ２值之间，表明叶鞘对Ｎａ＋、Ｋ＋向叶片的运输也有一定的选择能力。

The paper reported the selective absorption(SA)capacity of Na+ and K+ from the soil by root systemof puccinellia tenuiflora in jointing and mature stage in the field and the selective transportation(ST) capacityof Na+,K+ in different parts of the plant. The distribution characteristics of Na+,K+,Ca2-,Mg2+ and Cl-in different parts of the plant were also studied. The results indicated that SA value of the plant in maturestage is 1. 5 times higher than that of the plant in jointing stage,this suggested that the root system in theformer stage has stronger capacity to refuse Na+ a nd absorb K+ than that in the latter stage. ST1 ( root sys-tem : stem)Values of the plant both in jointing and mature stage are high,this suggested that root systemhas stronger capacity of limiting Na+ and promoting K+ to transport to the stem. In the jointing period,ST2(stem : leaf Sheath ) Value is low,which indicated that stem has weak selective transportation capacity toNa+ and K+; ST4(leaf sheath : blade)Value is between ST1 and ST2 , this showed that leaf sheath has tosome extent selective capacity for transportation of Na+ and K+ from itself to blade.