砷胁迫下磷用量对不同磷效率水稻苗生长、磷和砷吸收的影响

 通过盆栽试验研究了苗期砷胁迫下磷用量对磷高效水稻99011和磷低效水稻99056生长以及对P、As吸收的影响。试验设3个磷水平（0、30、150 mg/kg）和5个砷水平（0、25、50、100、200 mg/kg）。结果表明，苗期施砷显著增加了两个水稻品种地上部及地下部砷的含量，降低了两个水稻品种的株高、分蘖数、地上部及地下部干质量；施磷不但促进了两个水稻品种的生长，而且还增加了根系对砷的吸收量。当土壤砷浓度为25 mg/kg和50 mg/kg时，施用30 mg/kg磷抑制了两个水稻品种砷向地上部的转移，但施用150 mg/kg磷却促进了砷向地上部的转移。相同的处理，磷高效水稻99011地上部干质量和根干质量均显著高于磷低效水稻99056。施砷后，在30 mg/kg磷水平上磷低效水稻99056的砷转移系数最低。

Effect of Different P Levels on the Growth, P and As Absorption of Different P-efficiency Rice Varieties under As Stress Conditions at Seedling Stage

A pot trial was conducted to clarify the effect of different phosphorus (P) levels on the growth, P and arsenic (As) absorption of P efficient rice 99011 and P inefficient rice 99056 under As stress conditions. P was applied at three rates (0, 30 and 150 mg/kg) and As at five rates (0, 25, 50, 100 and 200 mg/kg) in soil.  Results showed that application of As increased shoot and root As concentration and decreased plant height, tiller number, shoot and root dry weight of the two rice varieties.  Application of P increased the growth as well as the root As concentration of the two rice varieties.  At 25 mg/kg and 50 mg/kg of As in soil, application of 30 mg/kg P decreased the translocation of As from roots to shoots and application of 150 mg/kg P increased the translocation of As from roots to shoots of the two rice varieties.  Under the same treatment, shoot and root dry weight of P efficient rice 99011 were significantly higher than those of P inefficient rice 99056.  Under the As treatment, the translocation factor of As in P inefficient rice 99056 minimized at 30 mg/kg P treatment.