Contribution of Nitrogen Uptake and Retranslocation during Reproductive Growth to the Nitrogen Efficiency of Winter Oilseed-Rape Cultivars (Brassica napus L.) Differing in Leaf Senescence
Contribution of Nitrogen Uptake and Retranslocation during Reproductive Growth to the Nitrogen Efficiency of Winter Oilseed-Rape Cultivars (Brassica napus L.) Differing in Leaf Senescence
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DOI：
10.3390/agronomy6010001
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发表时间：
2016-03-01
期刊：
影响因子：
3.7
通讯作者：
Horst, Walter J.
中科院分区：
文献类型：
--
作者：
Koeslin-Findeklee, Fabian;Horst, Walter J.
氮素效率的基因型变异主要归因于氮素吸收效率（NUPT），即在氮素供应有限的条件下，冬季油菜品系品种的高产。为了研究水稻生殖期保持绿色、氮素再转运和氮素吸收在籽粒产量形成中的作用，在不施用无机氮（N0）和施用160 kg Nha(-1) （N160）的条件下，对2个不同氮素饥饿诱导叶片衰老的品系进行了田间试验。通过从开花到成熟的频繁收获，可以计算出氮素吸收量、氮素利用率和从植物营养部分到荚果的表观氮素再动员。在限氮条件下，氮素利用率（NUPT）比氮素利用效率（NUE）对粮食产量的形成更为重要。不同品种氮素效率的差异，特别是花期氮素吸收（NUPT）和籽粒生物量分配效率（HI）是决定性的。两种作物性状均与老叶延缓衰老有关。在开花后，茎叶对氮素的再动员对荚果氮素的积累比对氮素的吸收更为重要。成熟时，豆壁（高氮浓度）和茎（高生物量）对作物残氮的贡献最大。减少冬季油菜作物固有的高氮收支盈余，需要提高籽粒低氮的再动员效率，特别是豆壁氮的再动员效率。针对这一结论，需要对包括杂交品种在内的品种进行多年和定点田间试验。
Genotypic variation in N efficiency defined as high grain yield under limited nitrogen (N) supply of winter oilseed-rape line-cultivars has been predominantly attributed to N uptake efficiency (NUPT) through maintained N uptake during reproductive growth related to functional stay-green. For investigating the role of stay-green, N retranslocation and N uptake during the reproductive phase for grain yield formation, two line cultivars differing in N starvation-induced leaf senescence were grown in a field experiment without mineral N (N0) and with 160 kg Nha(-1) (N160). Through frequent harvests from full flowering until maturity N uptake, N utilization and apparent N remobilization from vegetative plant parts to the pods could be calculated. NUPT proved being more important than N utilization efficiency (NUE) for grain yield formation under N-limiting (N0) conditions. For cultivar differences in N efficiency, particularly N uptake during flowering (NUPT) and biomass allocation efficiency (HI) to the grains, were decisive. Both crop traits were related to delayed senescence of the older leaves. Remobilization of N particularly from stems and leaves was more important for pod N accumulation than N uptake after full flowering. Pod walls (high N concentrations) and stems (high biomass) mainly contributed to the crop-residue N at maturity. Decreasing the crop-inherent high N budget surplus of winter oilseed-rape requires increasing the low N remobilization efficiency particularly of pod-wall N to the grains. Addressing this conclusion, multi-year and -location field experiments with an extended range of cultivars including hybrids are desirable.