|
In this study, the Chinese tallow tree ( Sapium sebiferum ( L. ) Roxb ) , hibiscus ( Hibiscus syriacus L. ) , sumac ( Cotinus coggygria Scop . ) , Fatong ( Platanus orientalis L. ) , Ash ( Fraxinus chinensis Roxb .) Of five species 1 year old seedling material with 0% , 0.2% , 0.4 % , 0.6 % NaCl saline solution treatment seedlings every four days time , one liter at a time . Salt treatment , 12 days , 24 days , 36 days, 48 ??days, and seedling survival , destruction of sampling , the root activity under salt stress , plant tissue ion content comparative study . And principal component analysis for multiple comparisons , stepwise regression , correlation analysis and mathematical methods for comprehensive evaluation , the study results show that : the seedling survival rate is a reliable indicator to measure the size of the salt resistance of seedlings , seedling salt tolerance order : pewter gt ; The Chinese tallow gt; hibiscus gt; sumac gt ; Fatong . Plants under salt stress , Na ~ distribution root up the stem , followed by leaves at least . The blades are the weakest parts of the plant salt tolerance . Hibiscus , sumac and other species by the main parts of the salt damage in leaves , roots, stems , is the main part of the Chinese tallow tree by the salt damage . Hibiscus , white wax and other species of root to stem , leaf selectively transport K ~ and limit the transport of Na ~ This is perhaps one of the main reasons for the salt tolerance of these species , sumac root to stem, leaf selective transport of Na ~~ limit K ~ transport , an excess of toxic ions Na to damage of the cell membrane system , resulting in membrane permeability , electrolyte leakage , a lot of the inflow of Na ~ cells , affecting the structure and function of a number of enzymes , destruction of cell metabolism . In the presence of relatively high concentrations of Na ~ interfere with the absorption of plant nutrient elements K and N , causing Nutrient Deficiency of plants , affecting growth and development , in addition to the improvement of the salt concentration in the root environment , water potential decline caused plant water absorption difficulties caused by osmotic stress . Together in ion toxicity , nutritional deficiency , osmotic stress , sumac , salt damage heavier . Should be noted that - grow roots to stems and leaves the transport K ~~ salt resistance is poor, may be Fatong sensitive lower amount of Na ~ can make Fatong hurt .
|