Abstract:

【Objective】Our aim is to explore the common characteristics of high-yielding and high quality indica hybrid rice varieties suitable for mechanical direct seeding in plain (Chongzhou) and hilly (Santai) areas and establish a standardized selection method and evaluation criteria for it, which could lay a theoretical and practical basis for the integration of hybrid indica rice mechanized seeding technology.【Method】Twenty-nine indica hybrid rice combinations were used as materials in two ecological zones, artificial simulated mechanized precise hill-seeding (mechanical direct seeding for short), and the effects of mechanical direct seeding on the population quality characteristics and yield of high-quality indica hybrid rice with different yield levels in plain and hilly areas were studied, the relationship between population quality characteristics and yield of high-quality indica hybrid rice combinations by mechanical seeding was also discussed.【Results】The results showed that, by cluster analysis based on average grain yield of each cultivars in the two areas, the 29 tested combinations could be classified into three groups: high-yielding, mid-yielding, and low-yielding. In the total tested cultivars, high-yielding combinations from Santai accounted for 17.24%, and other types covered 82.76%, high-yielding varieties from Chongzhou were 10.34%, and other types were 89.66%. Compared with the middle-yield and low-yielding varieties, the common high yielding varieties were featured by strong tillering ability, more effective panicles, higher seed-setting rate, higher leaf area index(LAI) after jointing stage and higher dry matter accumulation, moreover, its leaf length, leaf position, leaf opening angle of top three, plant height, top light energy intercept during filling exceled obviously. In addition to population light transmittance, leaf opening angle, tillering LAI and dry matter accumulation, correlation analysis indicated that there existed significantly or highly significantly positive correlations (r=0.37*-0.90**) between index of population quality and yield under mechanical direct-seeding, especially between high efficiency LAI rate at full heading, dry matter accumulation at maturity, and harvest index and yield.【Conclusion】High-yielding varieties have higher panicle and grain number per panicle, and seed-setting rate and high growth at late growth stage. That is how it can obtain higher yields under mechanical direct-sowing.

Key words: mechanical direct-sowing, indica hybrid rice varieties, yield type, yield formation, population quality

摘要：

【目的】本研究旨在明确适宜平原(崇州)与丘陵(三台)稻区机直播优质杂交籼稻高产品种群体质量的共性特征,构建规范化的机直播优质杂交籼稻高产品种的鉴选方法和评价标准,以及为杂交籼稻机械化直播配套技术的融合提供理论及实践依据。【方法】两生态区以29个品种为试材,采用人工模拟精量穴直播(以下简称机直播),研究机直播对平原与丘陵稻区不同产量水平的优质杂交籼稻群体质量特征及产量的影响,并探讨机直播优质杂交籼稻群体质量特征与产量间的关系。【结果】依据两生态区各品种的平均籽粒产量聚类分析,将两生态区供试品种分为高产、中产、低产3种类型。其中,三台高产类型品种占17.24%,中产、低产类型品种占82.76%;崇州高产类型品种占10.34%,中产、低产类型品种占89.66%。与中产、低产类型品种相比,两生态区高产类型品种的共性特征为分蘖能力强、有效穗数多、结实率高,拔节期后叶面积指数(LAI)大,干物质累积量高;结实期顶3叶叶长、叶位、叶张角、株高及其顶部截获光能优势明显。相关分析表明,机直播条件下,除群体透光率、顶3叶叶张角、分蘖盛期LAI及干物质累积量外,各群体质量指标与籽粒产量均呈显著或极显著正相关(r =0.37^*~0.90^**),尤其是齐穗期高效LAI率、成熟期干物质累积量及其收获指数与产量的相关性。【结论】机直播条件下,高产类型品种能够获得较高的有效穗数和每穗实粒数,并协同提高结实率,实现生育后期群体干物质的高增长,从而获得较高产量。

关键词: 机直播, 杂交籼稻品种, 产量类型, 产量构成, 群体质量