磷胁迫条件下落叶松幼苗对难溶性磷的利用

Utilization of insoluble phosphate by Larix gmelini seedlings under phosphorus starvation.

以AlPO4 为P源在温室内采用砂培的方法 ,研究了落叶松 (Larixgmelini) 2年生幼苗对难溶性P酸盐的利用状况 .结果表明 ,落叶松幼苗可以利用一定数量的AlPO4 .在供AlPO4 不接种菌根菌时 ,落叶松幼苗吸收的P可达正常供P时的 35 1%和 6 4 9% .不同菌种对落叶松幼苗利用AlPO4 的影响不同 .接种点柄乳牛肝菌(Suillusgranulatus)时 ,落叶松幼苗对AlPO4 的利用量高于不接种的 ,此时落叶松幼苗吸P量的 2 0 %和 35 %是来自于菌根的贡献 .接种厚环乳牛肝菌 (Suillusgrevillei)时 ,落叶松幼苗对AlPO4 的利用量与不接种的相近 .在P胁迫条件下 ,落叶松幼苗的根 /冠比加大 ,落叶松以加大根生长的方式来增加P的吸收 .

The utilization of insoluble phosphate by 2 years old larch( Larix gmelini) seedlings was studied in greenhouse.The seedlings were grown in sand and AlPO\-4 was supplied as a source of P.The results showed that larch seedlings could utilize some amount of AlPO\-4. Supplied with AlPO\-4 but not incubated with mycorrhizal fungi,the seedlings could absorb 35\^1% and 64\^9% of the phosphorus uptake when supplied with soluble phosphate.The effects of various mycorrhizal fungi on utilization of phosphate were different,i.e.,the utilization rate of AlPO\-4 was higher when incubated with Suillus granulatus ,but was similar to control when incubated with Suillus grevillei . The proportion of root/crown became higher under P starvation,and larch seedlings could gain more P by enlarging their root growth.