甜瓜种子萌发和幼苗生长对NaCl胁迫的响应

在盆栽条件下研究了NaCl胁迫对黄河蜜和白沙蜜甜瓜种子萌发和幼苗生长的影响。结果表明:NaCl胁迫对甜瓜种子吸水和累计发芽率影响较小,但明显延缓后期吸水和发芽进程。50 mmol·L-1以上NaCl浓度下,甜瓜种子相对发芽指数、相对活力指数和胚根生长量均下降。NaCl胁迫抑制甜瓜幼苗高度、株叶面积增长和干物质积累,抑制作用具有浓度和时间依赖性。NaCl胁迫对甜瓜幼苗形态生长的抑制作用强于对物质积累的抑制作用,对根系干物质积累的抑制作用高于对地上部干物质积累的抑制作用,对白沙蜜的抑制作用强于对黄河蜜的抑制作用。甜瓜种子和幼苗能适应的临界NaCl浓度在100~150 mmol·L-1之间,厚皮甜瓜可能更适合作为咸水灌溉和盐碱地生产的经济作物。

Responses of Seed Germination and Seedling Growth of Muskmelon to NaCl Stress

We have studied the effects of NaCl stress at different concentrations on seed germination and seedling growth of muskmelon.The results showed that NaCl stress had little effect on early water absorption and cumulative germination rate of muskmelon,but did delay late on water absorption and germinating course.NaCl treatments at concentrations above 50 mmol5L~(-1)decreased the relative germination and the vigor indexes of seeds as well as the radicle growth.The inhabitation of NaCl stress on seedling height,leaf area and dry matter accumulation depended on NaCl concentration and stress duration.The restraining effect of NaCl was higher on seedling morphological indicators than on biomass accumulation, stronger on root than on aboveground part,severer on cv.Huanghemi than on cv. Baishami.The critical concentration for muskmelon seed germination and seedling growth may be between 100~150 mmol5L~(-1),and cultivars from var.inodorus is more suitable for salt water irrigation and saline soil production.