鸭茅状摩擦禾种子质量提升的工艺与技术研究

发布时间：2018-01-21 11:23

本文关键词： 鸭茅状摩擦禾种子质量种子休眠种子处理去壳技术　出处：《中国农业大学》2016年博士论文　论文类型：学位论文

【摘要】：鸭茅状摩擦禾[Tripsacum dactyloids (L.) L.]是一种多年生暖季型丛生禾草,是草产品质量最好的牧草之一,被称作“禾草之王”。鸭茅状摩擦禾主要用于饲草料生产,还可用于控制土壤侵蚀,生产生物能源。此外,鸭茅状摩擦禾种子可作为谷物来源生产面粉和食用油等。生产过程中存在的种子产量不高、种子质量差以及种子休眠引起的建植困难等一系列问题限制了鸭茅状摩擦禾的推广种植。论文研究的目的是探究鸭茅状摩擦禾种子休眠的机理,确定可以有效破除种子休眠并提高种子质量的技术与方法,同时在不破坏颖果的条件下解决种子的去壳难题。论文研究发现,鸭茅状摩擦禾种子的种壳和种皮均延缓了颖果内部组织的水分和氧气的吸收,从而延缓了种子的萌发。为实现萌发,带壳种子比裸露颖果消耗了更多氧气。种皮是影响鸭茅状摩擦禾种子休眠和阻碍种子萌发的最关键因素。无论种壳存在与否,擦破种皮处理可以完全破除后熟种子批的休眠。足够长时间(8-12周)的冷湿层积处理也可以完全破除种子休眠。对冷湿层积处理的种子进行后干燥处理会导致休眠逆转,而擦破种皮处理可以解除休眠逆转。杀菌剂克菌丹(Captan)和福美双(Thiram)拌种处理中涉及的各化学成分对种子具有明显的植物毒性,从而降低了发芽率,因此不适合用于鸭茅状摩擦禾的种子处理。杀菌剂唑菌胺酯(Pyraclostrobine)和氟唑菌酰胺(Fluxapyroxad)无论是单独拌种还是以混剂形式拌种均可达到发芽率和霉菌控制的最佳效果。鸭茅状摩擦禾种子物理机械特性及压缩去壳试验结果显示,四倍体品种"Meadowcrest"种子尺寸和重量均大于二倍体品种"Pete",两个品种的颖果重量各占完整种子重量的1/4和1/3,完整种子长度约为颖果长度的两倍。种壳含水率显著低于颖果含水率。种子破裂力大小与压缩方向有关,轴向压缩时完整种子的破裂力仅为颖果破裂力的一半。种子尺寸、水分和破裂力共同决定了机械式轴向压缩可以有效分离鸭茅状摩擦禾种子的种壳并获得无损伤的颖果,有效分离率为84-87%。在批量压缩前进行长度分选分级处理并以不同压缩位移压缩能够将种子有效分离率提高至95%。基于此,论文提出了一种适用于鸭茅状摩擦禾种子的新的去壳工艺流程,并对压缩去壳装置整机及关键机构进行了设计。通过控制种子鼓风机清选中的气流速度可以分离没有活性的空瘪种子,从而提高种子批质量。完整种子、擦破种皮带壳种子和裸露颖果三种测试种子形态的最佳清选气流速度分别为9、10和12 m/s。对Westrup LA-LS风筛式清选设备风选系统的气流场进行模拟分析后表明,在吸风道风量调节阀倾角设定准确的条件下,可以确保鸭茅状摩擦禾种子达到最佳清选效果。前吸风道的调节确保轻杂被去除即可,后吸风道风量调节阀对应完整种子、擦破种皮带壳种子和裸露颖果的最适宜倾角分别为36°、270和90。虽然不同鸭茅状摩擦禾种子批间质量差异大,但采用合适的种子理技术和方法能够实现休眠的彻底破除,保证所有有活性的种子都能够在短时间内发芽。
[Abstract]:Tripsacum [Tripsacum dactyloids (L.) L.] is a perennial warm season bunchgrass, is one of the best forage grass product quality, known as the "king of grass". Tripsacum is mainly used for forage production, can also be used to control soil erosion, production of bio energy. In addition, Gama Wo seeds can be used as sources for the production of corn flour and edible oil. The seed yield in the production process is not high, cause a series of problems of planting Limited Tripsacum planting seed dormancy and seed of poor quality. The purpose of this study is to investigate the mechanism of Tripsacum seed dormancy. Sure can effectively break the seed dormancy and improve the techniques and methods of seed quality, and solve the problems in the seed shell does not destroy the caryopsis conditions. This study found that Tripsacum dactyloides seed species Shell and seed coat were delayed caryopsis internal organization of moisture and oxygen absorption, thus delaying the seed germination. For seed germination, consume more oxygen than naked caryopsis. The seed coat is the impact of Tripsacum seed dormancy and the key factors hindering seed germination. Both kinds of shell with or scrape the seed coat treatment can completely break dormancy ripening of seed batch. Enough long time (8-12 weeks) of cold wet stratification can completely break the seed dormancy. The cold wet stratification of seed drying after treatment may result in dormancy reversal, and dormancy scraping seed coat treatment can be reversed. Kranddan (Captan) and fungicides thiram (Thiram) relates to the chemical composition of seed processing plant has obvious toxicity on the seed germination rate, so as to reduce, therefore not suitable for seed treatment Tripsacum. Triazole fungicide Pyraclostrobin (Pyraclostrobine) and fluorine Pyraoxystrobin amide (Fluxapyroxad) either alone or in the form of dressing mixture can reach the best effect of seed germination rate and mildew control. Experiment results show that the compression and shell Tripsacum dactyloides seed physical and mechanical properties, the tetraploid cultivar "Meadowcrest" seed size and weight were higher than diploid varieties "Pete", two varieties of Caryopsis weight each accounted for 1/4 of the weight of intact seeds and 1/3, complete the seed length is about two times the length of the shell. Caryopsis water content was significantly lower than that of the caryopsis water content. The seed size and the direction of compression rupture force, rupture force axial compression of intact seeds is only half of the caryopsis rupture the seed size, moisture and rupture force determines the mechanical axial compression shell can effectively separate Tripsacum dactyloides seeds and without damage to the caryopsis, the isolation rate was 84-87 effective In front of the length of batch compression. Grading and deal with different compression compression displacement can be effectively separated the seed rate increased to 95%. based on this, the paper puts forward a suitable Tripsacum seed new shell process, and the compression shell unit and key flow mechanism design. By controlling the speed of seed cleaning blower can be selected separation of empty seeds have no activity, so as to improve the quality of seed lots. Intact seeds, seed shell and bare scrape belt Qing three test best caryopsis seed morphology of the flow speed respectively 9,10 and 12 m/s. of the Westrup LA-LS wind screen type cleaning air cleaning equipment air separation system the field simulation analysis show that the suction air flow regulating valve angle accurately set conditions, can ensure the Tripsacum seeds to achieve the best cleaning effect. The adjustable suction duct The light impurity removal can be that day, after the suction valve corresponding to intact seeds, seed shell and scrape the belt naked caryopsis most suitable angle of 36 degrees, 270 and 90. while the difference in quality between different batches of Tripsacum seeds, but completely get rid of by using appropriate techniques and methods to seed science the seed dormancy, ensure that all activity are able to germinate in a short period of time.

【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S543.9

【相似文献】