磷素水平对杂交水稻生长发育和磷素运移的影响

通过水培试验和32P标记，研究了不同P素水平下P素营养对杂交水稻D68生长发育的动态影响以及P在杂交水稻体内的运移动态。结果表明，P对杂交水稻生长发育起十分重要的作用，施P对杂交水稻发育特别是根系的生长发育、根系活性和地上部分干物质积累产生了极大的影响。通过32P标记结果表明，杂交水稻体内P的吸收累积、运移分布规律主要与根系活力和施P水平有关。P胁迫条件下杂交水稻根系中P含量较高而地上部分较低，P转移到地上部分的百分率较低；P充足条件下，稻株体内P主要累积在茎、叶中；根系活性的增强则进一步促进了P素养分的吸收以及P在杂交水稻体内的向上运移。同时P在杂交水稻体内的运移与水稻代谢和生长中心的转移密切相关，营养生长期P主要集中在茎、叶中；进入生殖生长期后，P由茎、叶向穗部转移，促进稻穗的生长发育。P在杂交水稻体内运移对杂交水稻P素营养具有极其重要的意义。

Effects of Phosphorus Levels on Hybrid Rice Growth and Characteristics of Phosphorus Transportation

By using nutrient solution culture and phosphorus isotope ( 32 P) tracing, the effects of phosphorus levels on hybrid rice D 68 growth and absorption transportation trend of phosphorus were studied during different growth stages. The results showed that phosphorus is very important for growth of hybrid rice, especially in root growth, root activities and the dry weight accumulation of hybrid rice. Isotope 32 P tracing had revealed that phosphorus accumulation and transportation in hybrid rice is mainly affected by the root activities and phosphorus concentrations. Further, at low and high P content, P accumulated in the roots with very little reaching the stems and leaves, suggesting reduced P transportation rates from root to upper parts. At abundant P content, P accumulated mainly in stems and leaves. As roots activities improving, the absorption and transportation from root to upper parts of P is increasing, obviously. The transportation of P is significantly related with metabolism and growth centers of hybrid rice, too. P is mainly distributed in stems and leaves in vegetative stages, and is transported from stems and leaves into spikelets in reproductive stage. It can be concluded that P transportation in plant is important for hybrid rice nutrition.