甬优系列籼粳杂交稻氮素积累与转运特征

摘要

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 in 2013–2014. 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/hm2in heading stage, 1.31% and 257.23 kg/hm2in maturity stage, which were higher than other two control types. The highest periodical N accumulation was 107.63 kg/hm2, with the highest proportion in total and periodical N uptake rate of 41.84% and 2.73 kg/(hm2·d) for the indica japonica cultivars in jointing to heading stage. The N contents of stem-sheath 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 37.54 kg/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 jointing-heading 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.%【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/hm2，成熟期植株含氮率与氮积累量分别为1.31%、257.23 kg/hm2，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/hm2，所占比例为41.84%，最大吸收速率为2.73 kg/(hm2·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。