NaCl胁迫对长江2号多花黑麦草种子发芽及幼苗生长的影响

Influences of NaCl stress on germination and seedling growth of italian ryegrass

以长江2号多花黑麦草种子为材料,设置5个NaCl浓度梯度(0.1%,0.2%,0.3%,0.4%,0.5%),通过测定发芽率、发芽势、幼苗生长速度及幼苗的SOD活性、MDA含量,分析盐胁迫对长江2号多花黑麦草种子发育及幼苗生长的影响。结果表明:种子的发芽率和发芽势,幼苗的株高和生长速度均受NaCl浓度影响。浓度大于0.1%时显著降低了种子发芽势,盐浓度大于0.2%时显著降低了种子发芽率。含盐量≤0.3%时显著降低了幼苗的相对生长速率。盐胁迫对幼苗鲜重和干重有显著影响,对幼苗含水量影响较小。0.1%NaCl处理下幼苗叶中SOD活性和CK差异显著(P<0.05),NaCl浓度大于0.2%时,叶中SOD活性和MDA含量逐步上升,0.5%NaCl胁迫下幼苗全部死亡。长江2号多花黑麦草的耐盐性较差,适宜在含盐量小于0.1%的土壤上种植和推广。

Germination rate,germination energy,seedling growth speed,SOD activity and MDA content of seedlings were studied under different NaCl concentrations（ 0.0%,0.1%,0.2%,0.3%,0.4% and 0.5%） with italian ryegrass（ No.2 Changjiang） an indicator crop.The results showed that germination rate,germination energy,height and growth speed of seedlings could be affected by Na Cl concentrations.Germination rate significantly decreased as the Na Cl concentration above 0.2% and germination energy significantly decreased as the Na Cl concentration above 0.1%.The relative growth rate of seedlings significantly decreased as the NaCl concentration above 0.3%.Effects of Na Cl concentrations on fresh weight and dry weight of seedlings were significant,but that on water content of seedlings was not significant. SOD activity and MDA content under Na Cl concentration of 0.1% were significantly lower than those under the control（ 0.0%）.SOD activity and MDA content significantly increased as the Na Cl concentration above 0.2%.Large amount of seedlings died under Na Cl concentration of 0. 5%. Italian ryegrass has a low salt tolerance,and was only suitable for production under NaCl concentration below 0.1%.