杂交水稻根际磷素的动态及利用

在灰棕紫泥水稻土上，杂交水稻土壤水溶性磷和有效磷，在根－上界面的浓度最低，随着根距的增加而上升，根－上界面Ｃａ－Ｐ减少最多，其次Ｆｅ－Ｐ和Ａｌ－Ｐ。水稻根际ＰＨ降低，根系Ｈ＾＋分泌增加，可能是促进Ｃａ－Ｐ转化的主要原因，在低磷或无磷条件下，根Ｈ＾＋分泌增加可视为磷胁迫下作物的一种适应性反应。

PHOSPHORUS STATUS AND UTILIZATION IN THE RHIZOSPHERE OF HYBRID RICE

A greenhotise pot experiment was conducted with hybrid rice to studypbosphorus(P) status and plant P utilization in the grey brown purplish rhizosphere soil .It was foundthat water-soluble P and available P were much lower on the rootsoil sarface nearby than faraway, Also, it was indicated that Ca-P decreased considerably in rhizosphere soil ascompared with Fe-Pand Al-P. Furthermore, the decrine of the rhizosphere soil pH wascaused by the increase of H secretion by the rice roots,and it may be a primarily factorthat Ca-P was transfered to other P status. Therefore,increase of H ecretion by rice roots under low P or no P conditions can be considered a beneficial adaptation.