土壤有效硅对大豆生长发育和生理功能的影响

人工调节土壤有效硅含量及盆栽试验，研究土壤有效硅对大豆生长发育和生理功能的影响。结果表明，土壤有效硅含量在55．1～202.8mg·kg^-1范围内，随着土壤有效硅含量的提高，大豆种子萌发过程中蛋白酶和脂肪酶活性升高，淀粉酶活性无显著变化，呼吸速率加快，种子活力升高，萌发速度加快，种子萌发率无显著变化；幼苗生长过程中叶片叶绿素含量无显著变化，光合速率加快，根系活力、硝酸还原酶活力升高，蒸腾强度减弱，水分利用效率和叶含水量升高，抗旱保水能力提高。大豆幼苗含硅量与土壤有效硅含量呈线性正相关趋势(r=0．994)。土壤有效硅含量大于2028mg·kg^-1，生理功能不再显著变化，说明土壤中的硅被大豆吸收后，改善了大豆萌发种子和幼苗的生理功能，使种子萌发和幼苗生长加快。

Effects of soil available silicon on growth,development and physiological functions of soybean

Soybean plants were planted in pots to investigate the effects of soil available silicon on their growth, development and physiological functions. When the content of soil available silicon was 55.1-202.8 mg.kg-1, the protease and lipase activities of germinating seed were increased with increasing soil available silicon content, amylase activity had no obvious change, and the respiration rate of seedlings was accelerated. The bioactivity of seed was increased, but the germination rate had no significant change. The photosynthesis rate, root activity, and nitrate reductase activity of soybean seedlings were enhanced, but the chlorophyll content in leaves had no significant change during seedling growth. The transpiration rate was decreased, while the water utilization efficiency and leaf water content were increased, and the capacity of drought-resistance was promoted. When the available silicon content was > 202.8 mg.kg-1, the abovementioned physiological functions had no significant changes. There was a positively linear relationship between the silicon content in soybean seedlings and the available silicon content in soil (r = 0.994). It could be concluded that the silicon absorbed from soil improved the physiological functions of soybean germinating seed and seedlings. As a result, the seed germination and seedlings growth rate were enhanced.