超高产栽培杂交中籼稻的生长发育特性

以5个杂交中籼稻品种(含品系)扬两优6号、P88S/747、珞优8号、珞优234和天两优2号为材料，研究大田条件下超高产水平(产量≥12.0 t hm^-2)的物质生产、产量构成及养分吸收特性。试验结果表明，与高产水稻(产量≥9.0 t hm^-2)相比，超高产水稻具有以下特征，幼穗分化期、齐穗期和灌浆结实期(齐穗后10 d) LAI大，分别为6.5~7.2、8.5~8.9和6.5~7.0；齐穗期的高效叶面积比率高，为60.0%~66.5%；齐穗期、灌浆期和成熟期积累较多的干物质，分别为13.5~15.0、15.0~16.0和25.0~28.0 t hm^-2；分蘖盛期对氮(N)、磷(P)、钾(K)吸收利用优势不明显，而幼穗分化期、齐穗期和成熟期对N、P、K 吸收利用高而且积累速度快。此外，具有穗数多(有效穗数介于250×10⁴ ~290×10⁴ 穗 hm^-2)、结实率高(88.2%~92.3%)、千粒重大(29.0~31.0 g)的特点。

Growth and Development Characteristics of Super-High-Yielding Mid-Season Indica Hybrid Rice

In order to study the characteristics of super high yielding (yield ≥ 12.0 t ha^-1) of mid-season indica hybrid rice cultivars in nutrition absorption, dry matter production and yield formation, we grew five rice cultivars (including lines), Yangliangyou 6, P88S/747, Luoyou 8, Luoyou 234 and Tianliangyou 2 in paddy fields. The leaf area index (LAI) at panicle initiation stage, heading stage and grain filling stage of super-high-yield rice was significantly higher than that of the high-yield rice (CK, Yangliangyou 6, grain yield ≥9.0 t ha^-1), which was in the range of 6.5–7.2, 8.5–8.9, and 6.5–7.0, respectively. The ratio of high effective leaf area to total leaf area at the heading stage was higher than that of CK, which was in the range of 60.0%–66.5%. Super high yielding rice had more dry matter accumulation than CK at the heading stage, grain filling stage and maturity stage, which was in the range of 13.5–15.0, 15.0–16.0, and 25.0–28.0 t ha^-1, respectively. Super-high-yield rice did not show any advantage in the absorption of N, P and K at mid-tillering stage compared with CK, however, had noticeable advantage in that at panicle initiation stage, heading stage and maturity stage. Furthermore, super high yield rice had more productive panicles, higher seed setting rate and grain weight in comparison with CK, which were in the range of 250×10⁴–290×10⁴ panicles per ha, 88.2%–92.3% and 29.0–31.0 g, respectively.