【摘要】 [目的]为揭示不同氮肥水平下籼粳亚种籽粒灌浆充实过程及其差异特性。[方法]以6个花期和生育期基本一致的优良籼粳亚种为供试材料,在抽穗期实施不同氮肥水平的处理,分析不同籼粳亚种籽粒灌浆的异同点,并探讨氮肥对其产生的影响。[结果]与粳稻相比,籼稻的千粒重和产量较高,结实率、充实率和充实指数偏低。籼稻强、弱势粒最终粒重（A）、最初生长势（R₀）、最大灌浆速率(G_max)、最大灌浆速率时的生长量(W_max·G)和平均灌浆速率(G_mean)均普遍高于粳稻,而灌浆峰值期(t_max·G)、达到G_max时的生长量比例（I）和活跃灌浆期（D）水平相对较低。总体而言,粳稻各时段的灌浆历时均比籼稻更长,平均速率（MGR）反而变小,灌浆贡献率（RGC）在前期占有一定优势,中期无明显差异,后期也较小;籼、粳大多数品种表现出中、后期强、弱势粒MGR和RGC对氮肥的响应规律比较一致,有与前期相反的趋势。就氮肥效应而言,适量氮肥（60 kg/hm² N2）提高了不同品种的千粒重和产量,结实率、充实率和充实指数变化不显著;籽粒灌浆参数和特征值的变化因品种和粒位不同导致敏感性不同。供试材料各时期灌浆历时随粒势升高而降低,MGR随粒势升高而升高,RGC表现并不完全一致。其中,粳稻品种间强、弱势粒灌浆特征值的差异在不同氮肥水平下均保持高度的一致性,而籼、粳亚种强势粒特征值随氮肥变化的反应有相反的趋势（除淮稻5号外）。相关分析表明,强、弱势粒灌浆速率与千粒重呈显著或极显著正相关,但与结实率和充实指标呈负相关;而强、弱势粒各阶段灌浆历时与充实指标呈正相关,尤其弱势粒达到了显著及以上水平,但与千粒重呈负相关。[结论]提高产量的关键在于根据目标性状筛选恰当的品种类型并配以适宜范围的氮肥。更多还原

【Abstract】 [Objective] To reveal the grain-filling process and different characteristics of subspecies of Indica and Japonica rice under different nitrogen fertilizer levels. [Method]Six fine Indica-Japonica subspecies with similar flowering and growth stages were used as test materials. Different levels of nitrogen fertilizer were applied at heading stage to analyze the similarities and differences of grain filling in different Indica-Japonica subspecies and explore the effects of nitrogen fertilizer on grain filling. [Result]Compared with Japonica rice, the 1 000-grain weight and yield of Indica rice were higher, while the grain-filling ratio, enrichment rate and enrichment index were lower. The final grain weight（A）, initial growth potential（R₀）, maximum grain-filling rate(G_max), amount of growth at the maximum growth rate(W_max·G) and mean grain filling rate(G_mean) of indica rice were normally higher than that of Japonica rice whereas the peak filling period(t_max·G), the proportion of growth when reaching G_max（I） and the level of active grouting period（D） were relatively low. In general, the grain-filling duration of Japonica rice was longer than that of Indica rice with the mean grain-filling rate（MGR） becoming smaller, the ratio of the grain-filling contributed to the final grain weight（RGC） had certain advantages in the early stage with no significant difference in the middle or late stage. Most of the varieties of Indica and Japonica rice showed that the response of the MGR and RGC to the nitrogen fertilizer in the middle and late stage was consistent among the superior and inferior spikelets, which was opposite to the early stage. In terms of the effect of nitrogen fertilizer, the appropriate amount of nitrogen fertilizer application（60 kg/hm² N2） increased the 1 000-grain weight and yield of different varieties, and the grain-filling ratio, enrichment rate and enrichment index did not change significantly;the changes of grain filling parameters and eigenvalues depended on variety and position of spikelet, causing the different sensitivity. The grain-filling duration of the test materials decreased with the increase of grain position, while the MGR showed a different picture, but the RGC performance was not completely consistent. The differences in the characteristics of the superior and inferior spikelets between the Japonica rice varieties were highly consistent under different nitrogen levels, while the traits of superior spikelets in the Indica-Japonica subspecies had opposite trends along the change of nitrogen fertilizer（except Huaidao 5）. Correlation analysis showed that the grain-filling rate of superior and inferior spikelets owned significantly or highly significantly positive correlation with 1 000-grain weight, but was negatively correlated with grain-filling ratio and enrichment index. However, the grain-filling duration of superior and inferior spikelets was positively correlated with the enrichment index, with a significance in the inferior spikelets but negatively related to the 1 000-grain weight. [Conclusion] The key to increasing yield is to screen the appropriate variety type according to the targeted trait and match the appropriate range of nitrogen fertilizer.更多还原