通过盆栽试验，比较分析了磷素对旱作条件下不同水稻品种苗期生长、根系形态及磷素吸收利用效率的影响。结果表明，施用磷肥促进水稻地上部和根系的生长，低磷胁迫显著增大了植物的根冠比，且品种间差异明显，丛矮2在低磷水平和高磷水平下的根冠比比值为 1.982，而黄华占相应的比值为1.096；随供磷浓度的增加，水稻植株含磷量增加而磷素生理利用率降低，在3种磷水平下，3345的磷素吸收效率均高于其他4个品种，磷素生理利用率却低于其他4个品种。根系形态参数与磷素吸收、利用效率的相关性分析表明：根系总长对水稻植株吸磷量影响最大。总之，适当地施用磷肥能更好地协调根系与地上部的关系，促进根系的生长和根系对磷素的吸收。

Based on pot experiment, the rice grown under dryland cultivation is selected to study the effects of phosphorus on seedling growth, root morphology, phosphorus uptake and physiological phosphorus use efficiency. Results showed that the application of phosphorus fertilizer promoted the growth of shoot and root of rice, the stress of phosphorus deficiency significantly increased the ratio of root to shoot, and there was significant genotypic variation in this ratio, the ratio of root/shoot under low phosphorus level and high phosphorus level was 1.982 for Cong-ai 2 cultivar and 1.096 for Huang-hua-zhan cultivar, respectively. With the increase of phosphorus concentration, phosphorus content in rice increased, whereas physiological phosphorus use efficiency decreased in the five rice cultivars. Under three phosphorus levels, phosphorus content of 3345 cultivar was higher but physiological phosphorus use efficiency was lower than other four cultivars. Further correlation analysis between root growth, phosphorus uptake and physiological phosphorus use efficiency showed that root length was significantly correlated to phosphorus content of rice. The application of phosphorus fertilizer can coordinate the relationship between root and shoot, and can promote the growth of root system and phosphorus content in plant.

S158.3

国家自然科学青年科学基金项目(31201690)资助