地黄野生种与栽培品种碳水化合物含量变化的比较研究

摘 要：旨在研究碳水化合物代谢在地黄块根膨大过程中的作用，为地黄增产和提高商品等级提供依据。可溶性糖含量的测定采用蒽酮比色法，单糖和低聚糖含量的测定采用HPLC法。单糖测定条件：流动相乙腈-水(85:15)，流速1.0mL/min，柱温40℃；低聚糖测定条件：流动相乙腈-水(70:30)，流速0.5 mL/min，柱温25℃；ELSD：增益300，漂移管温度40℃，氮气流速30 psi，喷雾器模式为冷却。（1）叶片中：与野生品种相比，栽培品种叶片中可溶性糖逐渐增加，低聚糖在拉线期、快速增长期逐渐上升，且含量高于野生品种；（2）块根中：二者变化规律大体相似。栽培品种根中果糖、葡萄糖、水苏糖和淀粉含量明显高于野生品种，而野生种块根中蔗糖含量高于栽培品种。地黄栽培品种的叶片具有更高的光合作用合成能力；生长期块根中蔗糖含量的降低可以提高“源-库”间蔗糖浓度的梯度，有利于光合作用同化产物从叶片运输到块根中，促进块根发育，从而提高产量。

Comparison of carbohydrate content variation between wild species and cultivars of Rehmannia glutinosa

The objectives of this study were to understand the role of carbohydrate metabolism in the enlargement of tuberous roots in Rebmannia glutinosa, and to provide a foundation for improving the yield and commercial grade of R. glutinosa. The content of soluble sugar was determined by anthrone colorimetry, and the contents of monosaccharide and oligosaccharide were determined by HPLC. Conditions for determination of monosaccharide content： mobile-phase acetonitrile-water （85：15）, flow rate 1.0 mL/min, column temperature 40℃; for oligosaccharide content： mobile-phase acetonitrile-water （70：30）, flow rate 0.5 mL/min, column temperature 25℃; for ELSD： gain 300, drift tube temperature 40~C, flow rate of nitrogen gas 30 psi, and spray pattern was cooling. The results showed that （1） in the leaves, soluble sugar content was increased in the cuhivar compared with the wild variety; oligosaccharide content was increased at elongate period and rapid growth period, and was higher than that of the wild variety. （2） In tuberous roots： the content variations in both varieties were roughly similar; the cultivar showed obviously higher contents of fructose, glucose, stachyose and starch than the wild variety, while the wild variety showed higher sucrose content than the cultivar. The leavesof the cuhivar showed higher photosynthetic capacity. During growth period, the decrease of sucrose content in tuberous roots could raise the gradient of sucrose contents between the ＂source＂ and the ＂sink＂. This variation would benefit the transportation of photosynthetic assimilation products from leaves to tuberous roots, and thus boost the growth of roots and increase the yield of R. glutinosa.