甬优系列籼粳杂交稻氮素积累与转运特征

Characteristics of nitrogen uptake, utilization and translocation in the indica-japonica hybrid rice of Yongyou series

【目的】比较分析甬优系列籼粳杂交稻氮素吸收利用与转运特征,从氮素层面阐明甬优系列籼粳杂交稻高产形成特征。【方法】2013~2014年,选用7个甬优系列籼粳杂交稻组合为试验材料,以2个常规粳稻品种和2个杂交籼稻品种为对照,比较研究甬优系列籼粳杂交稻主要生育时期植株含氮率、氮素积累量,不同生育阶段氮素积累量与吸收速率,抽穗期和成熟期各器官的含氮率和氮积累量所占比例,抽穗至成熟期各器官间的氮素转运,以及氮素利用效率等特征。【结果】甬优系列籼粳杂交稻抽穗期植株含氮率和氮积累量分别为1.47%、202.67 kg/hm^2,成熟期植株含氮率与氮积累量分别为1.31%、257.23 kg/hm^2,极显著大于对照类型。甬优系列籼粳杂交稻氮素最大阶段性积累量为107.63 kg/hm^2,所占比例为41.84%,最大吸收速率为2.73kg/(hm^2·d),且均出现在拔节至抽穗阶段,杂交籼稻出现在移栽至拔节阶段。甬优系列籼粳杂交稻抽穗期茎鞘和叶的含氮率分别为1.19%和2.34%,成熟期分别为0.75%和1.58%,高于对照类型。甬优系列籼粳杂交稻抽穗期茎鞘和叶氮积累量所占比例分别为43.92%和43.87%,成熟期分别为16.44%和17.44%,极显著大于杂交籼稻。甬优系列籼粳杂交稻氮素转运量大,表观转运率和转运贡献率不高,抽穗后的氮素净积累量贡献率为32.06%,显著大于对照类型。甬优系列籼粳杂交稻百公斤籽粒吸氮量为2.29 kg,极显著大于杂交籼稻;氮肥偏生产力为37.54 kg/kg,极显著大于常规粳稻;氮素籽粒生产效率、氮素干物质生产效率和氮素收获指数偏低。【结论】甬优系列籼粳杂交稻总吸氮量大,在拔节期足量氮素积累的基础上,提高了拔节至抽穗期与抽穗至成熟期两个阶段的氮积累比例;抽穗至成熟期茎鞘和叶的氮素转运量大,但表观转运率与表观转运贡献率低,抽穗后氮素积累优势明显,氮素净积累量贡献率高,满足了灌浆期籽粒对氮素的需求。

【Objectives】The objective of this study was to evaluate the nitrogen（N） uptake, utilization efficiency and translocation of the indica-japonica hybrid rice of Yongyou series and to identify the characteristics of their relationship with yield formation. 【Methods】Seven indica-japonica hybrid rice of Yongyou series cultivars, two japonica rice cultivars and two hybrid indica rice cultivars were used as experimental material in2013–2014. The characteristics of N content and N accumulation at the main growth stages, periodical N accumulation and periodical N uptake rate, N contents and ratios of N accumulation and translocation at the heading and maturity stages, N utilization efficiency were analyzed systematically. 【Results】The N content and N accumulation of indica-japonica hybrid rice of Yongyou series were 1.47% and 202.67 kg/hm^2 in heading stage, 1.31% and 257.23 kg/hm^2 in maturity stage, which were higher than other two control types. The highest periodical N accumulation was 107.63 kg/hm^2, with the highest proportion in total and periodical N uptake rate of41.84% and 2.73 kg/（hm^2·d） for the indica japonica cultivars in jointing to heading stage. The N contents of stemsheath and leaf were 1.19% and 2.34% in heading stage, 0.75% and 1.58% in maturity stage, which were higher than other two control types. The proportions of N accumulation in stem-sheath and leaf were 43.92% and 43.87%in heading stage, 16.44% and 17.44% in maturity stage, which were significantly larger than the hybrid indica rice. The N translocation amount was larger, but the apparent transport rate and transport contribution rate were low, and net N absorbed conversion rate after heading was 32.06%, which was significantly higher than the two contrast types. N uptake per 100 kg of grain was 2.29 kg and partial factor productivity of applied N was 37.54kg/kg, which were higher than the two control types. N utilization efficiency for grain, N utilization efficiency for biomass production and N harvesting index were lower. 【Conclusions】The indica-japonica hybrid rice of Yongyou series accumulate enough N at transplanting-jointing stage, and increase the proportion of jointingheading stage and heading-maturity stage. The N translocation amount in the stem-sheath and leaves from the heading to the maturity of the indica-japonica hybrid rice of Yongyou series is large. But the apparent N translocation rate and N translocation conversion rate are low. The advantage of net N accumulation after heading stage is obvious, which can meet the demand for N in grain.