摘要：
大穗型籼粳杂交稻颖花容易退化, 为明晰氮素对籼粳杂交稻颖花退化的缓解效应及其调控作用, 本研究以大穗型籼粳杂交稻甬优538为试验材料, 于2023年和2024年进行试验, 设置S1 (4月20日播种)、S2 (5月10日播种)和S3 (5月30日播种) 3个播期, 180 kg hm-2 (N12)、270 kg hm-2 (N18) 2种总施氮量, 以及T1 (在叶龄余数3.5施用100%穗肥)、T2 (在叶龄余数1.5施用100%穗肥)和T3 (在叶龄余数3.5施用50%穗肥+叶龄余数1.5施用50%穗肥) 3种穗肥施用方式, 分析比较不同处理下产量与产量构成、分蘖动态、颖花分化与退化、干物质积累和单朵颖花干物质占比变化。结果表明, (1) S1播期下N18T2处理的产量最高, 较S3播期下N12T1处理的产量平均提高46.83%; 其中播期对结实率影响最为显著, 其次影响每穗粒数; 不同施氮量对有效穗数和穗粒数有显著影响, N18处理较N12处理的穗粒数平均提高14.44%, 有效穗数平均提高12.88%。(2) 不同施氮量和穗肥施用时间对每穗粒数的影响主要在于颖花发育, N18处理较N12处理的氮含量平均提高22.51%, 2023年和2024年颖花分化数分别提高12.12%和15.35%, 现存颖花数分别提高16.00%和13.60%。穗肥施用时间后移可有效缓解颖花退化, 其中N12T3处理平均提高植株氮含量31.58%, N18T2处理平均提高26.29%; T2时期施用保花肥, 颖花退化率较T1平均减少18.20%, 较T3平均减少5.48%。(3) 颖花发育直接依赖于干物质积累, N18处理较N12处理, 穗分化始期干物质积累量(DM-SDI)显著提高6.96%, 穗发育期间干物质积累量(DM-SD)显著提高15.08%, 颖花分化数与DM-SDI、DM-SD呈正相关关系, 干物质积累越多, 颖花分化数越多。(4) 不同穗肥施用时间显著影响穗分化期间单朵颖花的干物质占比(SSDM-SD), T2>T3>T1; 颖花退化与SSDM-SDI、SSDM-SD呈负相关关系, 单朵颖花干物质越小, 颖花退化率越高。综上, 合理的氮素穗肥通过调控干物质积累来影响籼粳杂交稻颖花形成, 叶龄余数1.5时增施穗肥有利于提高单朵颖花的干物质占比, 支撑颖花生存和发育, 有效缓解颖花退化, 增加每穗粒数。在实际生产中, 可以适当提早播种, 在减少氮肥施用的基础上优化氮肥运筹(施用促花肥和保花肥), 可以延长营养生长期并提高单朵颖花干物质占比, 促进颖花分化的同时减少颖花退化, 进而达到籼粳杂交稻大穗栽培的目标。
关键词:
籼粳杂交稻,
氮素,
穗肥,
产量,
颖花分化与退化,
干物质积累
Abstract:
Spikelet degeneration is a common issue in large-panicle indica-japonica hybrid rice. This study investigated the effects of nitrogen application on mitigating spikelet degeneration and explored the underlying regulatory mechanisms. Field experiments were conducted over two years (2023 and 2024) using the large-panicle indica-japonica hybrid rice cultivar Yongyou 538. The experiment included three sowing dates (S1: April 20th; S2: May 10th; S3: May 30th), two nitrogen application rates (N12: 180 kg hm-2; N18: 270 kg hm-2), and three panicle nitrogen application timings: T1 (100% applied at leaf age remainder 3.5), T2 (100% at 1.5), and T3 (50% at both stages). The effects of these treatments on yield and its components, tiller dynamics, spikelet differentiation and degeneration, dry matter accumulation, and single spikelet dry matter accumulation were analyzed and compared. The results showed that: (1) Under the S1 sowing condition, the N18T2 treatment achieved the highest yield, averaging 46.83% higher than that of S3N12T1. Sowing date had the greatest effect on seed setting rate, followed by grains per panicle. Nitrogen application rate significantly influenced both effective panicle number and grains per panicle. Compared to N12, N18 increased grains per panicle and effective panicle number by 14.44% and 12.88%, respectively. (2) Nitrogen rate and panicle fertilizer timing mainly affected spikelet development. The nitrogen content in N18 plants was on average 22.51% higher than in N12. In 2023 and 2024, the number of differentiated spikelets increased by 12.12% and 15.35%, and the number of existing spikelets increased by 16.00% and 13.60%, respectively. Delayed panicle fertilizer application effectively reduced spikelet degeneration. The N12T3 treatment increased plant nitrogen content by 31.58%, and N18T2 by 26.29% on average. Spikelet degeneration rate in T2 was on average 18.20% lower than in T1 and 5.48% lower than in T3. (3) Spikelet development was directly dependent on dry matter accumulation. At the onset of panicle differentiation (DM-SDI), dry matter accumulation under N18 was 6.96% higher than under N12, and during panicle development (DM-SD), it was 15.08% higher. The number of differentiated spikelets was positively correlated with both DM-SDI and DM-SD, indicating that greater dry matter accumulation promoted spikelet differentiation. (4) The timing of panicle fertilizer application significantly affected the proportion of dry matter allocated to a single spikelet during the panicle differentiation stage (SSDM-SD), with the order T2 > T3 > T1. Spikelet degeneration was negatively correlated with single spikelet dry matter accumulation at both the onset (SSDM-SDI) and during development (SSDM-SD); lower accumulation corresponded to higher degeneration rates. In conclusion, optimized nitrogen management—particularly precise timing of panicle fertilizer application—regulates dry matter accumulation and significantly influences spikelet formation in indica-japonica hybrid rice. Applying panicle fertilizer at a leaf age remainder of 1.5 enhanced single spikelet dry matter accumulation, promoted spikelet survival and development, reduced degeneration, and increased grains per panicle. For practical cultivation, early sowing combined with optimized nitrogen management—especially split application at both 3.5 and 1.5 leaf age remainders—can extend the vegetative growth period, improve dry matter accumulation per spikelet, enhance spikelet differentiation, and reduce degeneration, even with reduced total nitrogen input.
Key words:
indica-japonica hybrid rice,
nitrogen,
panicle fertilizer,
yield,
spikelet differentiation and degeneration,
dry matter accumulation
引用本文
王晶卿, 陈惠哲, 兰天明, 李慧, 唐承翰, 马昕伶, 张玉屏, 王亚梁. 不同播期下氮素穗肥对大穗型籼粳杂交稻甬优538颖花退化的调控作用[J]. 作物学报, 2025, 51(10): 2759-2774.
WANG Jing-Qing, CHEN Hui-Zhe, LAN Tian-Ming, LI Hui, TANG Cheng-Han, MA Xin-Ling, ZHANG Yu-Ping, WANG Ya-Liang. Regulatory effect of panicle nitrogen fertilizer on spikelet degeneration in large panicle indica-japonica hybrid rice Yongyou 538 under different sowing dates[J]. Acta Agronomica Sinica, 2025, 51(10): 2759-2774.
使用本文
0
/
/
推荐
导出引用管理器 EndNote|Reference Manager|ProCite|BibTeX|RefWorks
链接本文:
https://zwxb.chinacrops.org/CN/10.3724/SP.J.1006.2025.52006
https://zwxb.chinacrops.org/CN/Y2025/V51/I10/2759