Abstract: New rice yield record was continued to be made under the idea of morphological improvement and heterosis utilization in recent years. The latest breakthrough of yield has been made last year and the new world record is 15.4 t/hm2 in Xupu County, Hunan Province, China. In this paper, the phase IV leading combination YLY900 was used as experimental material, and the control varieties were the phase III typical combination YLY 2 and the classical three-line combination Shanyou 63. The four elite factors in order to reveal the essence of high yield achieved in super hybrid rice were studied. These findings will provide theoretical basis and technical reference for super hybrid rice breeding and super high-yielding cultivation techniques. The main results were summarized as follows：（1）“Elite variety”: YLY900 had higher yield potential of 11.8 t/hm2 in normal ecological conditions, and the yield of YLY900 is 6.3% and 37.2% higher than that of YLY2 and SY63, respectively. The advantages were as follows: YLY900 had good plant type and high photosynthetic efficiency; YLY900 had reasonable tillering dynamics and high percentage of earbearing tiller; YLY900 had photosynthetic physiology advantage in middle and later stages; YLY900 had large panicle with high seed setting rate, which had enough “source”，large “sink” and fluent “flow”. （2） “Elite methods”: The total number of spikelets was up to about 5.0×107 per 667 m2, which guaranteed the grain yield is more than 15.0 t/hm2; Postponing nitrogen application and panicle fertilizer application time were crucial to super high-yielding. （3）“Elite field”: The high soil nutrient content and good air permeability of soil particle composition were the base of super high-yielding. （4） “Elite ecotype”: The excellent climatic ecological condition is a guarantee to obtain super high-yielding. The desirable climatic conditions for super high-yielding cultural techniques were as follows: average daily temperature of canopy during jointing stage to maturation stage is 25℃～28℃; the temperature difference between day and night is more than 10℃; the active accumulated temperature during the whole growth period is more than 3700℃; the sunshine hours is more than 1 200 hours.

Key words: super hybrid rice, Y Liangyou 900, 15.0 t/ hm2, matching technique of “four elite factors”

摘要： 近几年，以形态改良和亚种间杂种优势利用相结合的超高产育种成果不断涌现，2013年较大面积平均单产已达14.8 t/hm2，2014年这一数据又被刷新为15.4 t/hm2。本研究以第四期超级稻先锋组合Y两优900为试验材料，以第三期超级稻代表组合 Y两优2号及三系高产杂交稻汕优63为对照，通过对“良种”、“良法”、“良田”、“良态”配套技术系统研究，探索超级稻不断获取高产的原理和本质，旨在为今后水稻超高产育种及超高产栽培提供理论依据和技术参考。主要获得以下结果：（1）“良种”：Y两优900具有较高的产量潜力，一般生态条件下实际产量可达11.8 t/hm2，比汕优63和 Y两优2号分别增产37.2%和6.3%。其优势主要表现在：株叶形态好，光合效率较高；茎蘖发展合理，成穗率高；中后期光合生理优势明显；穗大结实率高，表现为“源”足、“库”大、“流”畅。（2）“良法”：穗粒结构设计合理，单位面积总颖花数达到5 000万/667 m2以上是单产超15.0 t/hm2的前提保障；氮肥后移和正确的穗肥施用时机是实现超高产的关键措施。（3）“良田”：土壤养分含量高和土壤颗粒组成的通透性好是超高产良田的重要构成因素。（4）“良态”：超高产栽培的适合气候生态条件为拔节至成熟期冠层日均温在25℃～28℃，昼夜温差大于10℃，全生育期活动积温3 700℃以上，日照时数超过1 200 h。

关键词: 超级杂交稻；Y两优900；15.0 t/hm2 ；&ldquo, 四良&rdquo, 配套技术