不同产量水平超级杂交稻产量形成特征及其对施肥量的响应

为了探究不同产量水平超级杂交稻产量形成特征及其对施肥量的响应,以超级杂交稻两优培九、Y两优1号、Y两优2号、Y两优900和超优千号为供试材料,研究不同施肥水平(纯N用量分别为0、210、300和390 kg/hm~2,N∶P_2O_5∶K_2O=2∶1∶2,以F0、F1、F2、F3表示)对各品种产量及群体质量的影响。结果表明,在施肥水平为F0和F1时,Y两优2号的产量比两优培九和Y两优1号高,主要表现在其具有较高的有效穗数,以及茎蘖成穗率、叶面积指数、干物质积累量和收获指数;在施肥水平为F2和F3时,Y两优900和超优千号产量较高,主要表现在其具有较高的每穗粒数,以及粒叶比和收获指数。在不同施肥水平下,随着施肥量的增加各品种的每穗粒数、粒叶比和收获指数呈先增后降的趋势,有效穗数和叶面积指数呈增加的趋势(两优培九除外)。由上可知,在相对较低的施肥水平下,Y两优2号相比于两优培九和Y两优1号能获得更高产量,主要依靠的是其具有较高的有效穗数;而在较高的施肥水平下,Y两优900和超优千号更具有获得高产的潜力,且主要依靠较高的每穗粒数,较低的有效穗数是限制其获得更高产的主要原因。

Effects of Fertilizer Application Rate on Yield and Population Quality of Super Hybrid Rice at Different Yield Levels

The effects of different fertilization rate (nitrogen fertilizer rate was 0, 210, 300 and 390 kg/hm2, N:P2O5:K2O=2:1:2, in F0, F1, F2 and F3, respectively) on yield and population quality was studied, using super hybrid rice LYPJ, YLY1, YLY2, YLY900 and CY1000 as materials. The results showed that the yield of YLY2 was highest in F0 and F1 level compared with LYPJ and YLY1, which showed higher effective panicles, earing percentage, leaf area index, dry matter accumulation and harvest index; the yield of YLY900 and CY1000 were higher when the fertilizer level was F2 and F3, which showed higher spikelet number per panicle, grain-leaf ratio and harvest index. With the increase of fertilizer amount, the spikelet per panicle, grain-leaf ratio and harvest index were in-creased first and then decreased, effective panicles and leaf area were increased (except LYPJ). As a result, YLY2 could obtain high yield in the lower fertilization level, mainly depended on the higher effective panicles. The yield of YLY900 and CY1000 had higher potential in the higher fertilization level, which mainly depended on higher spikelet number per panicle, their lower effective panicles was the main limiting factor for higher yield.