高寒草地牧草种子机械破眠损伤机理及低损破眠技术研究

The seed coat obstacle is one of the main causes for seed dormancy in alpine pasture. There are embryo and endosperm injury problems in the current mechanical dormancy breaking technology. In the present study, the compression mechanical properties of force-deformation curve, deformation, dormancy breaking force and dormancy breaking energy in the process of crush-breaking dormancy of grass seed in alpine pasture will be studied using static test and finite element analysis. The elastic modulus and allowable dormancy breaking stress will be analyzed according to Hertz theory. The law of friction-wear and the thermal behaviors between the grass seed in alpine pasture and different grinding materials will be studied using fractal theory, random process analysis method and test system of friction-wear mechanical dormancy breaking.The injury form, structure change and its discipline in seed mechanical dormancy breaking progress will be studied by electron microscopy and computer vision techniques. The aim is to elucidate the mechanism of mechanical dormancy breaking, and the injury mechanism of embryo and endosperm of grass seed in alpine pasture, and further provide theoretical evidence for principle and device of mechanical dormancy breaking. Meanwhile, a new dormancy breaking machine will be attempted to invent for reducing the injury rate of embryo and endosperm of grass seed in alpine pasture on the basis of its biological characteristics, methods and components of mechanical dormancy breaking. The study has an important practical and theoretical value for rehabilitation of degraded rangelands and construction of national ecological barrier.

种皮阻碍是引起高寒草地牧草种子休眠的主要原因之一。目前机械破眠技术存在着胚和胚乳损伤等问题。本项目将通过静力学试验和有限元分析，研究高寒草地牧草种子挤压破眠过程中的力-位移曲线、变形量、破眠力和破眠能等力学性质，并采用赫兹接触理论，分析种子单向表观弹性模量和破眠许用应力；应用摩擦磨损破眠试验系统和分形理论、随机过程等数学分析方法，研究不同磨料对高寒草地牧草种子的摩擦磨损规律及摩擦热行为；运用电子显微和计算机视觉技术分析胚和胚乳损伤形式、组织变化及其规律，揭示机械破眠以及胚、胚乳损伤机理，为探索机械破眠原理和研究机械破眠装置奠定理论基础。通过不同原理的机械破眠装置试验研究，以及种子生物学特性、机械破眠方式与机械破眠部件等因素间规律的分析，探求高寒草地牧草种子低损机械破眠方法，研制低损破眠设备。该研究对于高寒退化草地恢复重建以及国家生态屏障建设具有重要的现实意义与理论价值。

种皮阻碍是引起高寒草地牧草种子休眠的主要原因之一。我们通过静力学试验和有限元分析，研究了种子挤压破眠过程中的力-位移曲线、变形量、破眠力和破眠能等力学性质，分析了种子化学-力学特性之间的关系，完成了高寒草地牧草种子生物学特征与挤压破眠力学特性的研究，获得了硬实种子模型构建的规律，建立了准确的力学模型，获得了种子在不同载荷情况下的力学特性。选用型号为MXD-01型摩擦系数仪进行了种子静摩擦和动摩擦系数的测定与分析。采用赫兹接触理论，分析了种子单向表观弹性模量和破眠许用应力。应用摩擦磨损破眠试验系统，研究了不同磨料对高寒草地牧草种子的摩擦磨损规律及摩擦热行为。通过碾压式破眠装置、磨盘式破眠装置、滚筒式破眠装置和硬实种子破眠生产系统的试验研究，明晰了种子生物学特性、机械破眠方式与机械破眠部件之间的规律，揭示了机械破眠机理。研究对于高寒退化草地恢复重建具有重要的现实意义。