Effect Of Lycium Barbarum L.in Salinized Land On Soil Salt Content And Research Of Its Physiological Indexes

In this expriment, the Lycium barbarum L. in Jingtai County, Gansu Provience, was studied. And the content of proline, souble sugar, MDA, chlorophyll and inorganic ions in its different organ were measured to find out their distribution laws. In addition, seasonal change of salty ions in Lycium barbarum L. soil and the effect of microtopography on re-distribution of salty irons were studied. Main aim of this parper is to explore its mechanism of physio-ecological adaptation and its effect on salty ions in soils, which may offer useful theoretical foundation to generalize Chinese traditional medicine with highly officinal and economic values. The main results were as following: 1. The most important mechanism of Lycium barbarum L. adapting oneself to salt stress was in that it has osmoregulatory function. But in its body, inorganic ions and organic osmotic substances mainly accumulated in its overground and underground parts respectively, and the two kinds of substances had some complementarity each other in salt tolerance of Lycium barbarum L. 2. The distribution laws of Na+, K+ and Cl-in different organs of Lycium barbarum L. in salinized land were similar, and the order of their content was as following: leaves>stems>roots. But their distribution had difference between old leaves and young leaves. Na+ and Cl-content in old leaves was 0.64% and 0.32%, which was 1.39 and 1.45 times than their content in young leaves respectively. On the other hand, K+ content in old leaves(0.18%) was lower than its content in young leaves(0.65%). It could be indicated from the above results that Na+ and Cl-were firstly distributed to mature tissues with lower metabolic capability, and K+ content was higher in young tissues with higher metabolic capability under salt stress. K+ pool of Lycium barbarum L. were young leaves and stems, Na~+ pool were old leaves and roots. 3. The order of proline content in different organs of Lycium barbarum L. was as following: roots>stems>leaves, and the order of souble sugar was as following: roots>leaves>stems. There had some complementarity between proline and souble sugar in its upper parts. MDA content in underground parts of Lycium barbarum L. was higher than its content in overground parts, which was contrary with the distribution of proline and souble sugar and had some nagtive correlation with them. 4. Leaf fleshy of one-age Lycium barbarum L. was highest. It was 1.25 times than leaf fleshy of the four-age, and 2.20 times than mulberry leaves. Through correlation analysis, there had remarkable positive correlation between leaf fleshy of Lycium barbarum L. and Cl-content in it. 5. The difference of age of Lycium barbarum L. results in the difference of the above physiological indexes and ions in its organs. Na+ and Cl-content of four-age Lycium barbarum L. in leaves decreased 65.00% and 24.14% respectively, and their content in roots decreased 137.50% and 60.00%, compared with the one-age. The ratio of Na+ and K+ in leaves, stems and roots also decreased 101.12%, 202.82% and 236.36% respectively. Compared with the one-age Lycium barbarum L., proline content in leaves and stems of the four-age increased 28.05% and 137.59%, and its content in roots decreased 14.85%; souble sugar content of leaves and roots increased 21.75% and 12.19%, its content of stems decreased 11.12%; MDA content of roots and stems was higher, and its content of leaves was lower. With the increasement of age of Lycium barbarum L., chlorophyll content firstly increased greatly, then decreased, finally level off gradually. 6. Growth phase of Lycium barbarum L. also accumulation of irons and organic matters in its different organs. Compared with bud stage, the ratio of Na+ and K+ in leaves, stems and roots decreased 82.12%, 285.50% and 118.27% respectively during fruit stage, and Cl-content increasd 37.03%,171.43% and 162.50% respectively. The accumulation of organic matters had a general characteristic that relatively late growth phase owned more amount than early growth phase. 7. In 0-20cm soil layer, the seasonal change of soluble salt content in northwest inland was that it was higher in spring, decreased slightly subsequently, elevated quickly in July, decreased again with the increasement of rainfall, and rised finally in fall. The variational extent of bare soils was biggest, four-age Lycium barbarum L. soils was smallest, one-age Lycium barbarum L. soils was placed in the middle. The change of all kinds of satly ions has their own characteristics. 8. "Low groove and high ridge", which is a cultivated pattern, could affect re-distritution of salty ions. The total salt content of surface soil layer in high ridge was 2.05%, which has 2.23, 2.41 and 1.61 times than low groove, one-age Lycium barbarum L. flat and bare soils. As far as salty ions'contribution to this accumulation was concerned, the order of accumulation rate in 0-20cm soil layer was Na+>Cl->Ca2++Mg2+>SO42->HCO3->K+.