适宜低损失收获的油菜角果抗裂角性与分枝结构研究

Integration of agricultural machinery and agronomy is a short board in the current agricultural production process. Generally, there are some matching problems between biological characteristics of rape and combine harvester, which would lead to many problems in the field working process, such as, a relative higher rape seed losses, bad adaptability in threshing section and hole blocking on sieve surface. In this project, investigations on anti-crack properties of rape pod biology, which combined morphology, genetics, collision mechanics and stochastic process theory, will be carried out from the view of integration of agronomy and agricultural machinery, and hoping to obtain the candidate genes. To achieve this, rape varieties with different anti-crack properties of pod will be hybridized firstly and self-fertilized secondly, and these candidate genes in full length range will be copied and expressed. Then the morphological model of rape branching structure will be established, and its effect on loss of rape seed in cutting section will be studied. After that, the relevance among these genes will be analyzed. These studies would provide references for breeding experts of rape. According to these investigations and our experiences in rape harvesting, structures and dynamic parameters of the main parts of rape combine harvester, such as the parts in cutting section, threshing section and cleaning section, will be optimized to fit the actual requirements in combine harvesting process.

农机与农艺相融合一直是我国农业生产中的短板，在油菜机械化收获中普遍存在油菜生物形态特性与油菜联合收割机互不适应的问题，导致机械化收获时籽粒损失率大、脱粒适应性差和清选筛易堵塞等问题。项目从农机与农艺相融合的角度出发，基于生物学、形态学、遗传学、碰撞力学和随机过程理论等研究收获期田间条件下主要种植油菜品种的角果抗裂角性，获得抗裂角性差异显著的典型油菜角果品种并进行杂交和自交，筛选并全长克隆表达分析油菜角果抗裂角候选基因；建立油菜分枝结构形态描述模型，探讨油菜分枝结构对切割分禾籽粒损失的影响并进行基因相关性分析。获得适宜油菜机械化低损失收获的角果抗裂角性和分枝结构的相关基因及其表达水平，为农艺育种提供参考依据。结合油菜机收的经验，根据油菜角果抗裂角性特性和分枝结构特征，对油菜联合收割机的切割分禾和脱粒分离、清选等主要工作装置的结构、工作参数进行优化，探索更适宜区域油菜收获的机械化联合收获技术。

农机与农艺相融合一直是我国农业生产中的短板，油菜机械化联合收获损失高的主要原因是联合收割机与油菜角果抗裂角性和油菜植株分枝特性之间不匹配，角果抗裂角性差，分枝过多交叉缠绕和角果成熟不一致是存在的主要问题。本项目从机械化联合收获油菜角果的实际工况出发，设计了角果抗裂角性二自由度碰撞法，在2016至2019年间，使用该方法与已有拉裂法和随机碰撞法对不同油菜品种进行了抗裂角对比试验，调查统计了各品种的农艺性状和植物几何学特性，同时对不同因素对角果抗裂角性的影响进行了分析；为降低割台损失，采集测试了收获过程中不同转速下拨禾轮弹齿与油菜间的碰撞力，对田间收获期望角果抗裂角大小进行了分析；并根据油菜株型，改进了拨禾轮结构和轨迹；同时对相关品种材料进行了转录组测序分析，从分子层面上进一步了解油菜分枝及角果抗裂角性的调控机理，并于2020年，对筛选出符合的收获特性的油菜品种进行了联合收获对比验证试验。研究结果表明，二自由度碰撞测试法对不同油菜角果的抗裂角性区分度更大，结果更可靠，角果更利于筛选更为可靠的适宜机械化收获的抗裂角性品种，且两自由度碰撞仪可移至田间测试从而真实反映角果特性；油菜品种、角果着生位置也对角果抗裂角性和角果尺寸大小均产生了显著性影响；对于田间整株油菜角果，分枝角果抗裂角性显著大于主花序角果，主花序顶部角果抗裂角性最差；拨禾轮18rev/min 时满足收获要求的角果抗裂角指数应大于0.583；改进后拨禾轮具有较低的割台损失率，在拨禾轮转速为18rev/min，机器速度为0.6m/s，拨禾轮高度为1100mm时损失最低为1.04%；筛选出的品种C6009田间试验损失率显著低于对比品种NY12。本研究深入研究角果抗裂角性与分枝特性及对机械化收获的影响，为农艺专家改良油菜品种，农机专家优化油菜收获机均提供切实可靠的参考依据。