油-稻-稻三熟制下双季稻高产品种特征研究

【目的】在早稻-晚稻-套播早熟油菜(油-稻-稻)三熟制下,筛选生育期适宜的高产水稻品种,系统研究早、晚稻高产品种特征,以期为油稻稻三熟制下水稻高产品种的选育与栽培提供理论参考。【方法】以9个早稻品种和10个晚稻品种为材料,通过系统聚类分析和方差分析等方法对油稻稻三熟制下双季稻高产品种特征进行研究。【结果】(1)与低产和中产类型双季稻相比,高产类型双季稻有效穗数、结实率、千粒重、生育期差异不显著,但每穗粒数、总颖花量、产量及日均产量显著高于低产类型。(2)高产类型与低产及中产类型双季稻的分蘖增长率、分蘖下降率及高峰苗数差异不显著,但成穗率显著高于低产类型,高产类型分蘖呈稳增缓降的发展态势。(3)早稻抽穗期干物质量及各生育时期平均单茎干物质量不同类型间无显著差异,结实期与全生育期干物质量随产量水平的提高呈增加趋势,高产类型显著高于低产类型;晚稻各生育时期干物质量及平均单茎干物质量不同类型间差异较大,高产类型均显著高于低产类型,但与中产类型差异不显著;各产量类型品种收获指数差异不显著。(4)随产量水平的提高,双季稻抽穗期和成熟期群体叶面积(LAI)和单茎叶面积呈增加趋势,灌浆结实期叶面积下降率则呈降低趋势,高产类型与低产类型均存在显著差异;粒叶比随产量水平的提高而增大,其中早稻高产类型与低产类型差异显著,而晚稻差异不明显。【结论】在油稻稻三熟制条件下,高产类型双季稻具有分蘖力中等、成穗率较高、全生育期特别是花后干物质生产量及单茎干物质量大、中后期LAI及单茎叶面积较高、每穗粒数较多、总颖花量大、粒叶比协调和日产量高等基本特征。高产类型早稻品种生育期为105—110 d,日产量75—78 kg·hm-2·d-1,每穗粒数125—140粒,千粒重26—28 g;高产类型晚稻品种生育期约115 d,日产量77—81 kg·hm-2·d-1,每穗粒数140—160粒,千粒重24—28 g。

Characteristics of High-Yield Double Rice Varieties in Rice-Rice-Rapeseed Cropping System

【Objective】This study was conducted to determine the characteristics of high-yield double rice cultivars by using high-yield rice cultivars with suitable growth period in triple cropping pattern of early rice-late rice-interplanting early-maturing rapeseed (rice-rice-rapeseed cropping system), which would provide grounds and references for breeding and cultivation of high-yield double rice cultivars.【Method】9 early rice cultivars and 10 late rice cultivars were employed in field experiments of rice-rice-rapeseed cropping system, and characteristics of high-yield double rice cultivars were studied by using cluster analysis and variance analysis methods.【Result】(1) There were no significant differences in panicle number, seed setting rate, 1000-grain weight and growth period among the three yield types (high-yield (HY), middle-yield (MY) and low yield double rice cultivars (LY) ). However, the number of grains per spike, total spikelet volume, yield and daily yield of HY were significantly higher than that of LY. (2) There were no significant differences in increase rate of tillering, decrease rate of tillering and number of peak tiller between HY and LY, while the rate of effective ear of HY was significantly higher than that of LY. (3) For early rice, HY showed higher biomass in heading and biomass per stem in heading and maturity, followed by MY and LY, with no significant differences among them, yet the total biomass and biomass per stem of HY were significantly higher than that of LY. As for late rice, there were significant differences in total biomass and biomass per stem in heading and maturity between HY and LY. As to harvest index, there were no significant differences among the three yield types of both early and late rice. (4) HY showed higher leaf area index (LAI) and leaf area per stem in heading and maturity, as well as lower reduction rate of leaf area form heading to maturity, followed by MY and LY, with significant differences between HY and LY. And also, HY showed higher spikelet number per leaf area, followed by MY and LY, with significant differences between HY and LY of early rice.【Conclusion】In rice-rice-rapeseed cropping system, high-yield double rice cultivars were characterized by medium tillering ability, high earing rate, powerful abilities of dry matter per stem and high LAI as well as high leaf area per stem in mid and latter stages, large number of spikelets and high daily production. While some differences were existed between early rice and late rice. For early rice, it was about 105-110 d of growth duration, 75-78 kg·hm^-2·d^-1 of daily yield, 125-140 spikelets per panicle, and 26-28 g for 1000-grains. As for late rice, it was about 115 d of growth duration, 77-81 kg·hm^-2·d^-1 of daily yield, large number of the grains (140-160 spikelets per panicle), and 24-28 g for 1000-grains.