不同水稻品种获取氮能力的差异

Difference in N uptake capacity between different rice genotypes

采用溶液培养方法研究了不同水稻品种获取氮能力的差异及其原因。结果表明,在不同供氮水平下,不同水稻品种吸氮能力差异显著。随着供氮水平的提高,南光、豫粳7号、黔育421和武运粳7号的氮积累总量增加显著,说明这4个水稻品种对氮的响应度高;而桂单4号、ELIO、云粳38和4007的氮积累总量增加不显著,说明它们对氮的响应度低。对氮响应度高的4个水稻品种的平均吸氮速率随着供氮水平的增加其增幅显著,而其总根长的变化幅度则较小。水稻氮积累总量与总根长和平均吸氮速率的相关关系的分析结果表明,平均吸氮速率对水稻苗期获取氮能力的贡献率大于其总根长的贡献率。

Hydroponic experiments were conducted to study nitrogen （N） uptake of eight rice eultivars under three N concentrations （ 1, 2 and 4 mmol/L, respectively）. The results showed that there were significant differences on N uptake capacity between different rice eultivars. N accumulation in Nanguang, Yujing 7, Qianyu 421 and Wuyunjing 7 was significantly increased with increasing of N application rate indicating those cuhivars had higher responsiveness to N, however, no significant enhancement of N accumulation was observed in Guidan 4, ELIO, Yunjing 38 and 4007 suggesting that those eultivars had lower responsiveness to N. Difference in N uptake responsiveness was linked to their difference in N uptake rate and root characteristics. N uptake rate of high-responding eultivars increased significantly with increasing N rate, while their total root length exhibited a comparatively lower variation. Further correlativity analysis between N accumulation in rice and total root length and mean N uptake rate showed that mean N uptake rate was of bigger contribution on rice N acquisition in seeding than total root length.