该研究以淀粉含量不同的两个木薯品种(辐选01和华南124)为材料,通过测定各品种不同生育期叶、茎和根的蔗糖含量及块根淀粉含量,分析了蔗糖合成、转运和块根淀粉积累过程的相关性.结果表明:与华南124相比,在整个生育期内辐选01叶、茎的蔗糖含量均较高,块根蔗糖含量在块根膨大初期以前高于华南124,块根膨大初期以后则相反.在木薯的整个生育期,与辐选01相比,华南124的淀粉合成量和淀粉合成速率均较低.叶和茎蔗糖含量的变化规律与淀粉合成速率的变化规律相反,即块根淀粉积累明显加快时叶和茎的蔗糖含量略呈下降趋势,而块根淀粉合成减慢时叶、茎的蔗糖含量又开始上升.随着生育期的延后,块根蔗糖含量越来越低.在块根形成初期,蔗糖含量最高的组织部位为块根,其次为茎秆,最低的是叶片;而在块根成熟期时则相反,即蔗糖含量最高的部位是叶片,其次为茎杆,块根的蔗糖含量最小.相关性分析结果表明,木薯叶片蔗糖含量与块根淀粉含量呈显著的正相关;茎秆蔗糖含量与块根淀粉积累量呈不显著的正相关;块根蔗糖含量与淀粉积累量呈显著的负相关.由此可见,木薯叶、茎和根蔗糖与块根淀粉积累过程密切相关,其中叶片合成蔗糖的能力与块根利用蔗糖的能力在淀粉的积累过程中发挥关键作用.该研究结果为木薯的生产选育与高效栽培提供了理论依据.%Two cassava cultivars with different starch contents were taken as materials in the study, and were Fuxuan 01 and SC124. The relationship between sucrose' s synthesis, distribution and the starch accumulation in the root tuber was studied. Leaf, stem and root sucrose accumulation and starch accumulation in the root tuber of different cassava cultivars were determined, and their relations were analyzed in the different growth periods, respectively. The results showed that thecontent of sucrose in Fuxuan 01' s leaf and stem washigher than that of SC124 in all periods, and the accumulation of su-crose in root was higher than that of SC124 before initial stage of root tuber thickening, but lower after initial stage of root tuber thickening. In the whole growth period, the starch content and starch synthesis rate in the root tuber of Fuxuan 01 were higher than that of SC124. Root ' s sucrose content was significantly declined with the growth period delayed. The change trend of sucrose content in leaf and stem was opposite to that of starchsynthesis rate, which indicated that sucrose content in leaf and stem decreased while the root starch accumulation rate increased, and the sucrose content in leaf and stem increased while the rate of starch synthesis reduced obviously. The root was the part with the highest content of su-crose, then followed by the stem, and the part with the lowest content of sucrose was leaf in the early root formation period. But the trend was opposite in the mature period, it was the leaf part with highest content of sucrose, then followed by the stem, and the part with lowest content of sucrose was root. The results of correlation analysis showed that the correla-tion between the sucrose content in leaf, stem and the starch accumulation in root tuber of cassava was positively related. The relation was significant between the starch accumulation in root tuber and the sucrose content in leaf but not in stem. The correlation between the starch synthesis in root tuber and the sucrose content of cassava was significantly negative-ly related. The relationship between sucrose's transportation, distribution and the root's starch accumulation in cassava was closely related, and the abilities of synthesizing sucrose in leaf and utilizing sucrose in root tuber play key roles in the process of starch accumulation. This study provides the information for the production and breeding of cassava.
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