Compare Ative Study On Growth Characteristics And Nitrogen Utilization Among Ten Varieties Of Italian Ryegrass Under Cu²⁺ Treatment

In this research, a pot experiment often varieties of Italian ryegrass was carried out. It studied the growth and nitrogen utilization efficiency under different concentration of soil copper treatment, so as to fully understand and grasp the mechanism of copper tolerant in plant physiology and provide a theoretical basis for the cultivation of copper tolerant mechanism, the advisable differences of nitrogen, which provides some theoretical basis to soil remediation, food safety and variety selection. The main results are as follows:1. Low concentration of Cu2+treatment (50mg/kg) can increase fresh and dry matter yield, the plant height, tiller number, regenerate height but reduced the stem/leaf. High concentration of Cu2+treatment (150mg/kg、300mg/kg)can significantly decreased fresh and dry matter yield, the plant height, tiller number, regenerate height, which increases the stem/leaf (P<0.05)2. The concentration of chlorophyll in the Italian ryegrass leaves decreased as the Cu2+treatment increased. In different growth stages, the root activity was correlated negatively with the concentration of Cu2+. The proline content in leaves of the ten varieties of Italian ryegrass was improved under low concentration of Cu2+treatment and the cell membrane permeability was significantly improved under Cu2+treatment (P<0.05)3. The concentration of MDA in leaves decreased under low Cu2+treatment, but significantly improved when the concentration of Cu2+at150mg/kg(P<0.05). The CAT. SOD, POD activitives in different growth stage showed some changes after different Cu2+treatment.4. With the increasing of Cu2+treatment the crude protein(CP), the crude ash(CA) and neutral detergent fiber(NDF)in different parts of Italian ryegrasses increased at first and then decreased.5. The Fe, Zn element in the leaves and stems of Italian ryegrasses decreased significantly increased after different Cu2+treatment (P<0.05). The calcium (Ca) and phosphorus (P) concentration in different parts of Italian ryegrass showed no regular trends.6. The Cu2+accumulation in the different tissues of Italian ryegrass was positively correlated with the concentration of Cu2+. The Cu2+accumulation in the roots of Italian ryegrass was higher than that in stems and leaves.7. Low Cu2+treatment improved nitrogen utilization efficiency of ten Italian ryegrasses, but the efficiency significantly decreased when concentration of Cu2+at150mg/kg (P<0.05).8. As a whole, Waseaoba and Harukaze have some advantages in resisting Cu+tretment of Italian ryegrass. The results suggested that Italian ryegrass may be cultivated on the polluted soil, in which Cu2+concentration is lowed than50mg/kg.