马铃薯不同品种淀粉积累生理基础研究——淀粉积累与磷酸化酶、蔗糖转化酶的关系

本试验以高淀粉品种晋薯２号、中淀粉品种内薯３号、低淀粉品种紫花白为材料，对不同生育时期块茎淀粉含量、淀粉积累速度与淀粉磷酸化酶、蔗糖转化酶活性的关系进行了研究，其结果表明：全生育期３个品种淀粉磷酸化酶活性均呈单峰曲线变化；不同生育时期，各品种淀粉含量与淀粉磷酸化酶活性无明显规律性；不同生育时期，各品种淀粉积累速度与淀粉磷酸化酶活性呈正相关。淀粉含量和温度是影响淀粉磷酸化酶活性的两个重要因素，而温度又起主导作用。全生育期，３个品种的蔗糖转化酶均呈苗期为最高，中期显著下降，后期略有回升的变化趋势；不同生育时期，各品种淀粉含量与蔗糖转化酶活性均呈显著负相关；不同生育时期，各品种淀粉积累速度与蔗糖转化酶活性亦呈负相关。因此，蔗糖转化酶活性可作为马铃薯高淀粉育种早期选择的重要生理指标。

STUDY ON PHYSIOLOGICAL BASIS OF STARCH ACCUMULATION IN DIFFERENT VARIETIES OF POTATO ——RELATION BETWEEN STARCH ACCUMULATION AND AMYLOPHOSPHORYLASE,SUCROSE INVERTASE

Different potato varieties (Jin #2 high starch content, Nei #3 medium starch content and Zihuabai low starch content) were used as experimental materials to study the relation between starch content, rate of starch accumulation and activity of amylophosphorylase, activity of sucrose invertase. The result were as follows. The activity of amylophosphorylase changed as a single peak curve for the three varieties during the whole growth phase. Starch content had no dovious correlation with the activity of amylophosphorylase, but the rate of starch accumulation had a positive correlation with the activity of amylophosphorylase for the varieties during various growth stages. Starch content and temperature were important factors which affected the activity of amylophosphorylase, and the latter played a leading role. The activity of sucrose invertase was high in the seedling stage, declined remarkably in the middle stage and had a little rise again in later stage. During various growth stages, starch content and the rate of starch accumulation all correlated negatively with the activity of sucrose invertase. Therefore, the activity of sucrose invertase could be used as an important physiological character of early selection for high starch during potato breeding programme.