酸性土壤上不同水稻品种耐低磷差异研究

Study on Difference of Low Phosphorus Tolerance of Rice Varieties in Acid Soil

针对红壤性水稻土酸化和磷有效性低的问题,筛选出酸性土壤上耐低磷水稻品种,解析其耐低磷机制,对发挥酸性土壤上水稻生产力和降低磷肥施用具有重要意义。在前期田间试验的基础上,选用了6个水稻品种(敖柱、连粳7号、A类黄、一支腊选系、南充一支腊、马扎),采用土培和水培试验,研究了酸性土壤上不同水稻品种耐低磷能力的差异及其机制。结果表明:水稻品种敖柱、连粳7号和A类黄耐低磷能力较强,另外3个品种耐低磷能力较差;耐低磷水稻品种敖柱和连粳7号在土培低磷条件下显著提高了根际的磷含量,同时,在水培低磷条件下具有较高的磷吸收效率;水培条件下低磷显著诱导水稻根系的生长,耐低磷水稻品种敖柱的诱导效应尤其明显。因此,根际磷活化、高效磷吸收和根系增大是酸性土壤上水稻耐低磷的主要机制,但是不同水稻品种可通过不同机制来适应低磷胁迫。

In order to solve the problems of acidification and low phosphorus availability in red soil,enhancing lowphosphorus(P) tolerance of rice in acid soil is of great significance for increasing rice yield and decreasing the application of P fertilizer in acid soil.Based on the previous field experiment,6 rice cultivars(Aozhu,Lianjing 7,A Huang,Yizhila,Nanchong Yizhila and Maza) were used as the test materials,and the mechanism of rice tolerance to low-P stress was studied by the experiments of soil and water culture.The results showed that Aozhu,Lianjing 7 and A Huang had higher low-P tolerance compared with other three varieties.Rhizosphere P activation of Aozhu and Lianjing 7 occurred under soil culture,but other rice cultivars did not.Meanwhile,these two rice cultivars had higher P uptake efficiency under hydroponic conditions.Low phosphorus significantly enhanced the root growth of rice under hydroponic conditions,especially for the cultivar Aozhu.It was concluded that rhizosphere P activation,strong P uptake efficiency and big root system are three main mechanisms for the low-P tolerance of rice plants,but different rice cultivars can adapt to low-P stress through different mechanisms.