不同氮素水平下恢复系及杂交稻组合氮肥高效利用

为了比较利用MAS选育的氮高效型恢复系及其杂交稻组合在不同氮素水平下的农艺性状差异。本研究以抗病虫害和氮高效的多基因聚合恢复系R4302、R4312及其配制的8个杂交稻组合为试验材料,‘华占’‘天优华占’为对照,设置0 kg/hm²（N₀）、112.5 kg/hm²（N_112.5）、150 kg/hm²（N₁₅₀）、187.5 kg/hm²（N_187.5）4个氮肥水平,成熟期测定与分析供试材料的单株有效穗数、单株产量、干物质产量、氮肥农学利用率、氮肥偏生产力和收获指数。结果表明,不同氮素水平下R4302各农艺性状均优于‘华占’,R4312除氮肥农学利用率外其他农艺性状优于或接近‘华占’,表明OsTCP19基因的丢失并未影响R4302、R4312氮肥的高效利用;杂交稻组合天丰A/R4302、天丰A/R4312为氮高效型组合;贵A/R4302、科20A/R4312、香龙A/R4302、科4364A/R4312为低氮高效型组合;荃9311A/R4302属于双高效型组合;科20A/R4302属于高氮高效型组合;恢复系可用单株产量、氮肥农学利用效率、干物质产量其中1项指标或有效穗数来评估氮肥的利用效率;杂交稻组合可用单株产量、干物质产量、氮肥偏生产力、氮肥农学利用率、有效穗数、收获指数其中1项指标来评估氮肥的利用效率。本研究为通过氮高效基因选育氮肥高效利用型恢复系和杂交水稻组合提供参考。

Analyse of Nitrogen Fertilizer Efficiency of Restorer Lines and Hybrid Rice Combinations under Different Nitrogen Application Levels

The agronomic characters of nitrogen efficient restorer lines and their hybrid rice combinations breeding by MAS were compared under different nitrogen levels. It would provide references for breeding nitrogen use efficiency parents and hybrid rice combinations with nitrogen use efficiency genes. Restorer lines R4302, R4312 and 8 hybrid rice combinations were used as the materials, the control varieties were ‘Huazhan’ and ‘Tianyouhuazhan’. Four nitrogen fertilizer levels; 0 kg/hm² (N₀), 112.5 kg/hm² (N_112.5), 150 kg/hm² (N₁₅₀) and 187.5 kg/hm² (N_187.5), were used. Panicles per plant (PPP), yield per plant (YPP), dry matter biomass (YPP), nitrogen harvest index (NHI), agronomic efficiency (AE) and partial factor productivity (PFP) at mature stage were evaluated. R4302 and R4312 contained nitrogen efficient gene OsNRT1.1B but not OsTCP19. All agronomic traits of R4302 were better than those of ‘Huazhan’ under different nitrogen levels. Except agronomic efficiency the other agronomic traits of R4312 were better than or close to ‘HuaZhan’. The loss of OsTCP19 gene did not affect the nitrogen use efficiency of R4302 and R4312. Tianfeng A/R4302 and Tianfeng A/R4312 were nitrogen efficient combinations. Gui A/R4302, K20A /R4312, Xianglong A/R4302, K4364A /R4312 belonged to the low nitrogen and high efficiency combinations. Quan 9311A/R4302 was the double efficiency combination. K20A /R4302 was the high nitrogen efficiency combination. The agronomic efficiency of nitrogen fertilizer, dry matter yield, yield per plant or panicles per plant could be used to evaluate the nitrogen use efficiency of restorer lines. The dry matter yield, nitrogen partial productivity, nitrogen agronomic efficiency, panicles per plant, harvest index or yield per plant could be used to evaluate the nitrogen use efficiency of hybrid rice combinations. This study would provide a reference for the breeding of nitrogen efficient restorer lines and hybrid rice combinations by nitrogen use efficiency genes.