三种狼尾草耐盐性研究

Research on Salt Tolerance of Three Pennisetum Species

中文关键词: 狼尾草  耐盐性  盐胁迫

英文关键词: Pennisetum spp.  salt tolerance  salt stress

中文摘要:

      为了掌握3种狼尾草的耐盐性，对其进行为期30 d的盐胁迫试验,设置0.25 g/kg、0.35 g/kg、0.5 g/kg、0.6 g/kg、0.8 g/kg 5个土壤含盐量梯度处理，以清水为对照，测定相关形态及生理指标。结合植株死亡率、枯叶率、株高和茎叶生长量的试验结果表明，3种狼尾草耐盐能力由强至弱的次序为:‘小兔子’狼尾草＞羽绒狼尾草＞‘紫光’狼尾草，它们能够忍受的土壤含盐量分别为0.6 g/kg、0.5 g/kg、0.35 g/kg。随着土壤含盐量的增加，3种狼尾草叶片中SOD、CAT及POD的活性均呈现先升高后降低的变化趋势，其中SOD活性变化幅度最大。随着盐胁迫的加重，‘紫光’狼尾草SOD活性在0.35 g/kg轻盐胁迫时最早出现峰值，其次为羽绒狼尾草，在0.5 g/kg中盐胁迫时达到峰值，‘小兔子’狼尾草在0.6 g/kg中盐胁迫时出现峰值，这与枯叶率和茎叶生长量的研究结果相一致，因此可以通过测定SOD活性峰值判断其能耐受的土壤含盐量。

英文摘要:

      In order to investigate the salt tolerance of three Pennisetum species, salt stress test has been carried out for 30 days. The salinity gradients in soils are treated as five levels, including 0.25g/kg, 0.35g/kg, 0.5g/kg, 0.6g/kg and 0.8g/kg, to study their morphological and physiological changes compared with clear water treatment. The test results on the plant mortality, percentages of dead leaves and the growth of stalk and leaf, show that the order of the salt tolerance of three species from strong to weak is as follows: Pennisetum alopecuriodes ‘Little Bunny’, P. setaceum ‘Rueppelii’ and P. alopecuroides ‘Ziguang’, their salinity tolerance corresponding with 0.6g/kg, 0.5g/kg and 0.35g/kg in soils respectively. With increasing salinity, the activity of SOD, CAT and POD in the leaves of all three Pennisetum species shows a trend of increasing first and then decreasing, especially the activity of SOD with the greatest change. The activity of SOD in P. alopecuroides ‘Ziguang’, P. setaceum ‘Rueppelii’， P.alopecuriodes ‘Little Bunny’ reaches the peak values at the salinity levels of 0.35g/kg, 0.5g/kg and 0.6 g/kg, respectively, which is coincident with the results of percentages of dead leaves, and the growth of stalk and leaf. Therefore, the salt tolerance can be estimated by measuring the peak values of SOD activity.