NaCl胁迫对甜、爆、糯玉米幼苗生长及活性氧代谢的影响

以3种不同的特用玉米(沈糯6号、沈爆3号、沈甜6号)为试材,设置5个梯度的NaCl盐溶液(0、50、100、150、200mmol/L)进行盐胁迫处理,测定玉米幼苗的生长量、干物质积累量、质膜透性、活性氧代谢等的变化。结果表明,随着NaCl盐浓度的增加,植株生长量明显降低,单株鲜重、干重均明显降低,干物质积累减少,电导率不同程度地增大,丙二醛含量逐渐升高;超氧阴离子(O2-)产生速率在各处理间差异显著,随着处理浓度的增大,O2-产生速率也显著增加;超氧化物歧化酶(SOD)活性在3个品种间变化不同;过氧化物酶活性(POD)在沈糯6号和沈甜6号间表现为逐渐上升,而沈爆3号先上升后下降;过氧化氢酶(CAT)活性在3个品种间均在150mmol/L时达到最大。从总体上看,耐盐能力相对较强的是沈糯6号,较弱的是沈甜6号。

Effects of NaCl Stress on Plant Growth and Active Oxygen Metabolism in Seedlings of Sweet, Pop and Glutinous Corn

Three special types of corn (Glutinous Shennuo6, Pop Shenbao3, Sweet Shentian6) were stressed with five different gradients of NaCl salt (0, 50, 100, 150, 200 mmol/L) during seedling growth stages, then height, fresh weight and dry weight, plasma membrane permeability, active oxygen metabolism were detected. The results showed with the stress prolonging, plant growth of the three varieties decreased evidently, fresh weight and dry weight in individual plant both decreased significantly, dry matter accumulations decreased, conductivity increased in different degrees, MDA content gradually rose, the rate O₂^- produced had a significant difference among these levels, with the concentration increasing, the rate O₂^- produced also increased obviously, SOD activity changed inconsistently in three varieties, POD activity of Shennuo6 and Shentian6 both increased slowly, which of Shenbao3 increased in early phase and afterwards declined, CAT activity of the varieties put on the maximum in the level of 150 mmol/L NaCl. Generally, the salt tolerance of Shennuo6 was relatively higher and that of Shentian6 was lower.