本文构建了一种基于图像的半自动的大田作物根系表型分析方法，包括图像采集、图像去噪与分割、特征提取和数据分析四个模块，能够提取5个全局特征和40个局部特征。通过对比人类统计的一级侧根分支数和本文构建的方法提取的结果，发现二者之间具有较好的一致性，R²高达0.97。在玉米/大豆间作系统中，基于该方法提取的根系表型特征参数，进一步发现玉米的种间优势主要表现在5-7轮节根基部5cm内，而间作系统对大豆的明显抑制作用主要体现在主根基部20 cm范围内。因此，本文为大田根系形态和拓扑表型特征的研究提供了一种高通量和高精度的新方法，可以潜在的应用于大田根系三维结构的重建，以及根系生长、溶质运输和水分吸收的模型模拟（例如OpenSimRoot）。

叶型和茎型是水稻株型的核心冠层结构特征，决定了及其冠层光截获能力，直接影响着作物产量。PLANT ARCHITECTURE AND YIELD 1(PAY1)基因被证实能够改变野生稻匍匐特性，对野生稻匍匐生长习性基因PROSTRATE GROWTH 1（PROG1）具有一定抑制作用。本文选择含有PROG1基因的水稻材料YIL55及其突变体PAY1，以及其母本TQ为供试材料，基于三维数字化测定技术，构建了三种株型水稻的冠层三维结构模型。在此基础上，定量分析在PAY1基因作用下，植株叶型和茎型在拔节期、抽穗期和灌浆期的变化。结果表明，在PAY1基因影响下，植株茎叶夹角显著降低并趋于直立，叶片增大，植株茎集散度由松散型转变为紧凑型，三个关键生育期时的平均茎倾角由44.9°、28.5°、21.3°分别减小至17.6°、8.4°、10.5°。此外，PAY1基因保留了PROG1基因水稻全生育期分蘖角度动态变化的特性，茎集散度由拔节期的松散型变化为抽穗期时的紧凑型。冠层光合有效辐射测定结果也表明突变体PAY1的株型结构更有利于冠层底部的光截获，其在早、中、晚的消光系数分别为0.535、0.312、0.586，均低于其他两种株型。本文通过定量分析PAY1基因对水稻冠层结构特征的影响，旨在为株型选育提供有效冠层结构特征参数，为理想株型育种提供借鉴。

The North China Plain (NCP) is one of major breadbaskets in China. Crop growth and grain yield differ significantly with spatial variations of soil properties. This study aims to identify the key soil properties in relation to the grain yield for the winter wheat (Triticum aestivum L.)-maize (Zea mays L.) cropping system in a high-productivity farmland of the NCP. The field trials were conducted in three fields with different grain yield levels in Tai’an City, Shandong Province, China, during the 2009–2012 period. Consistent field management strategies were applied in the three fields. Fifty-one physical and chemical indicators of the soil profile as related to grain yield were evaluated. An approximate maximum of 17.8% annual average grain yield difference was observed in the fields during the period of 2009–2012. The soil indicators were classified into three clusters with specific functions using cluster analysis, and three key indicators were extracted from each cluster to characterize the different soil properties of three fields. The first cluster represented soil water retention capacity, and the key indicator was available soil water (ASW), which ranged from 153 to 187 mm in the 1.2 m profile and was correlated positively with grain yield. The second cluster represented soil water conductivity, as measured by saturated hydraulic conductivity (Ks). The higher yield field had a greater capacity to retain topsoil water for its lower Ks (1.9 cm d–1) in the 30–70 cm soil layer as compared to the lower yield field. The third cluster represented nutrient storage and supply, as indicated by the ratio of nutrient content to silt+clay content of the top soil layer. The ratio of soil organic matter (OM), total nitrogen (TN), available P, exchangeable K+ to silt+clay content in the 0–20 cm soil layer were 19.0 g kg–1, 1.6 g kg–1, 94.7 mg kg–1, 174.3 mg kg–1 in the higher yield field, respectively, and correlated positively with the grain yield. By characterizing the differences in soil properties among fields with different yield levels, this study offers the scientific basis for increasing grain yield potential by improving the soil conditions in the NCP.