不同木薯品种抗衰老生理与淀粉积累特性研究

以新选056、南洋红、GR891、辐选01、华南124和新选048共6个木薯品为材料，于生育后期分析其叶片过氧化物酶活性、丙二醛、可溶性糖、自由水、束缚水含量以及块根淀粉积累等，以探讨木薯衰老生理与块根淀粉积累的关系。研究结果表明，不同木薯品种生育后期抗衰老生理与淀粉积累特性有明显差异，生育后期茎叶生长和生理机能最旺盛的是华南124，最弱的是南洋红，居中的是辐选01、GR891、新选048和新选056。木薯后期茎叶生长状况对块根淀粉积累有明显影响，过早衰老，降低块根淀粉含量及块根产量；过旺使光合产物大量用于地上部分茎叶生长，而运到地下部的相对减少，从而降低块根淀粉积累和块根产量。因此，木薯生育后期茎叶生长的调控，使其保持在适当水平，是提高木薯块根淀粉积累和块根产量的一项重要措施。同时，生育后期抗衰老生理指标也可作为高产和高淀粉含量品种选育的参考。

Characters of Anti-Senility Physiology and Starch Accumulation in Different Cassava Cultivars

Cassava is a starch crop, and its root tuber is main economic product. How to increase starch content in the root tuber is a very important problem in cassava breeding and cultivation. The characters of anti-senility physiology and starch accumulation of six different cassava cultivars Xinxuan056, SC201, GR891, FuxuanO1, SC124, and Xinxuan048 were studied during the late growing period in this experiment. The result showed that the leaf and stem growth function of SC124 was most vigorous while that of SC201 was most feeble and that of Xinxuan056, GR891, FuxuanO1, and Xinxuan048 was on the suit level in the late growing period. The soluble sugar content, the peroxidase activity, the MDA content in the leaves and the starch accumulation in the root tubers of SC124 were the lowest. The soluble sugar content in the leaves and the starch accumulation in the root tubers of GR891 were higher than those in other cultivars. The MDA content in the leaves and the numbers of leaf abscission of SC201 were the highest and its starch accumulation in the root tubers was lower than that of other cultivars except SC124. The effect of leaf and stem growth in the late growing period on the starch accumulation in the root tubers of cassava was obvious. Not only the root tuber yield but also the starch accumulation in the root tubers obviously decreased if the leaves and stems senesced in the early stage of root tuber formation. But if the leaves and stems grew too vigorously, which hindered carbohydrate transferring from the leaves and stems to the root tubers in the middle or late root tuber formation stage, the yield of root tuber and the starch accumulation in the root tubers decreased. It is important to control the leaf and stem growth on a proper level in the middle or late stage of cassava root tuber formation. Meanwhile the characters of anti-senility physiology and starch accumulation can be used as the index as of selection in high starch content cultiars breeding of cassava.