球勺内窝孔垂直圆盘排种器伤种过程计算机模拟

球勺内窝孔垂直圆盘排种器适合于单粒点播或定粒穴播作物。根据该排种器的排种原理,不应有种子损伤。但试用结果实际伤种率高于国家标准规定。因而如何降低其伤种率成为研制该排种器的难点。该文建立了种子的运动数学模型和力学数学模型,利用模拟方法,从运动学角度对排种器工作过程进行模拟,为排种器参数的优化提供依据,降低排种器的伤种率。

小麦精密排种器伤种的计算机模拟

内充种垂直轮式小麦精密排种器(专利号:ZL98244378.1)实现了小麦精密播种的精确、定量、可控,播种量的确定性和播种均匀性高于其他小麦排种器,解决了小麦精密排种的关键。根据该排种器的清种原理,不应有种子损伤。但试验结果表明其伤种率高于国家标准规定。因而解决如何降低其伤种率即成为研究该排种器的难点。本研究从种子的损伤形式入手,分析了种子尺寸、排种器的结构参数和运动参数对种子损伤的影响,并用计算机仿真模拟进一步优化了该排种器的结构和参数。

内侧充种圆盘排种器防伤种装置的设计

内侧充种圆盘排种器在花生播种等方面有着广泛的应用,但中高速度下播种效果不理想,原因是充种区种子易卡滞,护种板入口处未清净种子分离不清易发生磕种。为此,在原有排种器的基础上,添加了辅助充种装置,在清种区与护种板入口处衔接位置设计出一种全新的防伤种隔种板,并就隔种板橡胶的特性、排种盘转速这两个影响新设计性能的因素进行了理论分析。基于JPS-12型排种器试验台,对改进后的排种器进行了排种性能试验,测得重播率、漏播率、破碎率等主要性能指标。试验表明,改进后的内充种式圆盘排种器在15cm和20 cm两理论粒距水平下均达到优等品标准。

内侧充种垂直园盘排种器伤种机理的研究

内侧充种垂直园盘排种器在构造上没有清种、刮种、推种装置，就此而言，不应损伤种子，但实际并非这样。本文根据课题组对该排种器的发展创新和应用其研制精密播种机中的经验或教训，从充种方式、参数选择、加工工艺诸多方面分析了伤种机理。

外槽轮排种器伤种浅析

外槽轮排种器广泛使用在谷物条播机上,其中NJ210-80小外槽轮排种器因其结构简单、制造和使用方便而受到用户的欢迎。但由于其结构本身的原因及过去制造质量差,造成对种子的损伤,降低了田间出苗率、浪费了不少种子。 据有关资料介绍,外槽轮排种器伤种的主要原因有: 1.槽轮与排种舌间夹种引起伤种。

芥蓝与菘蓝族间原生质体融合及杂种愈伤分析

运用聚乙烯乙二醇（PEG）和二甲基亚砜（DMSO）共同诱导融合的方法，成功获得芥蓝与菘蓝原生质体融合的再生愈伤。利用9对SRAP随机引物对亲本和再生愈伤DNA进行扩增以鉴别再生愈伤的基因组成，结果表明：在再生愈伤的DNA条带中，与供体菘蓝相同的带占93．07％～94．16％，与受体芥蓝相同的条带占70．24％～75．78％，并有少量新增带和缺失带出现，再生愈伤的DNA带型为双亲的叠加，为真正的族间杂种愈伤。类平均法（UPGMA）聚类分析表明，5个杂种愈伤明显聚在一起，其遗传组成十分相似，与菘蓝的遗传关系较近，而与芥蓝的遗传关系稍远。

两种抗生素对水稻种胚愈伤组织诱导和分化的影响

研究了两种抗生素对水稻种胚愈伤组织诱导和分化的影响。结果表明：供试抗生素卡那霉素（Ｋａｎａｍｙｃｉｎ，Ｋｍ）和氨苄青霉素（Ａｍｐｉｃｉｌｌｉｎ，Ａｐ）对水稻种胚愈伤组织的诱导和生长都发生抑制作用，而Ｋｍ比Ａｐ的抑制作用强。不论诱导期还是分化期用Ｋｍ５０、１００ｍｇ／ｋｇ处理，除可培养出少量白化苗外，２００ｍｇ／ｋｇ以上剂量处理的均未能分化出绿苗。仅分化期用Ａｐ处理，５０～２００ｍｇ／ｋｇ浓度促进了绿苗分化，但浓度达４００ｍｇ／ｋｇ时则开始发生抑制作用。诱导期用Ｋｍ处理的愈伤组织，在分化期其死亡率随浓度的提高而提高。而仅在分化期用Ｋｍ和Ａｐ处理的愈伤组织，虽也有不同程度的致死现象，但数量较少。Ｋｍ＋Ａｐ对愈伤组织的诱导和生长具有累加抑制作用。在分化期处理，Ａｐ可部分解除Ｋｍ对绿苗分化的抑制效应。文中还讨论了Ｋｍ和Ａｐ作为检测是否导入外源基因的适宜浓度。

杂交稻种发生损种伤芽的原因及预防对策

本文总结了杂交稻种发生损种损芽的原因,并提出防治对策。

双层滚筒气吸式水稻育秧播种机问世

我国重点推广种植的杂交水稻要求精播旱育稀植。随着机械抛秧、摆秧、插秧技术的推广应用,对秧苗质量要求更高,工厂化育秧成为必然趋势,因此需要大量适合育秧工厂使用的塑料穴盘式播种机。目前较具代表性的有两种机型,一种为槽轮(或窝眼轮)机械式排种装置的播种机,这种机型的优点是生产率较高,空穴率小,能连续生产;缺点是种子落盘随机性大,入穴均匀性差,单穴入种量大,由于机械磨擦和挤压作用易伤种,铺覆土采用,对床土颗粒大小、均匀度要求高,成本较高,作业受阴雨天影响。另一种机型为气吸式水稻播种机。

谷物籽粒损伤研究现状

谷物籽粒损伤影响谷物品质,对谷物损伤相关研究进行分析,可为提高谷物品质,减少谷物损伤提供重要的理论依据。本文在总结和整理现有国内外谷物籽粒损伤研究成果的基础上,结合谷物自身特点,分析和讨论谷物理化性质对损伤的影响、损伤主要表现形式的相关研究、损伤的检测方法、对谷物损伤的研究方法以及机械作业过程中损伤影响因素的研究五个方面的内容,综述了谷物自身含水率和蛋白质占比对损伤影响较大,视觉检测与图像处理法检测损伤应用较广泛,试验与有限元结合是目前常用的研究方法,机械作业过程中参数的优化可有效降低谷物损伤。针对谷物损伤的研究现状和存在的不足,提出培育耐损伤的谷物新品种、完善有限元模拟仿真试验参数、调节机械作业参数等重要策略,以期能有效提高谷物品质,优化机械作业效率。

肇庆及周边地区毒蛇咬伤流行病学调查研究

目的总结肇庆及其周边地区人群毒蛇咬伤情况,以了解其流行病学特征,掌握各地区毒蛇的分布特点及毒蛇咬伤常见多发蛇种,为制订符合实际有效的预防对策及诊断、治疗措施提供依据。方法回顾性分析我院2010年1月~2019年12月收治的3319例毒蛇咬伤患者的临床资料。结果肇庆及其周边地区是毒蛇咬伤高发区,其发生率与地处山区、季节、职业和工作环境有密切关系。竹叶青蛇咬伤病例占多数,其次为眼镜蛇、烙铁头蛇咬伤。毒蛇咬伤全年均有发生,以7~10月份发病率最高。蛇伤高发人群主要为务农者,且以30~49岁人群为主,致伤部位主要为四肢。结论肇庆及其周边地区毒蛇咬伤全年均有发生。采取相应的预防、宣传、教育措施,建立健全蛇伤救治体系,对降低毒蛇咬伤的发生率、提高救治成功率具有重要意义。

水稻直播机关键部件的设计与试验研究

水稻直播具有节省育苗和插秧成本,适合大规模机械化作业等优点,目前已成为国内外研究的热点。为了解决我国现有水稻旱直播机尚无成熟机型、无法实现精量穴播等问题,通过田间试验发现该直播机存在的问题,运用SOLIDWORKS三维软件对2BD-10型水稻旱直播机的排种器、开沟器、镇压轮等零部件进行改进设计,并对排种器和镇压轮进行力学分析,建立数学模型;并利用仿真分析方法对关键部件进行分析,确定该设计有利于提高排种均匀性和覆土效果。据此设计了一种勺式水稻旱穴直播机,实现了一次完成施肥、旋耕、开沟、排种、镇压等功能,并通过测量平均每穴粒子数、排种均匀性、伤种率、开沟深度、覆土厚度等试验进行验证。试验结果表明:该机的每穴粒子数平均值为15粒、平均每穴粒子数变异系数为9%、排种均匀性变异系数为4.7%,伤种率在2%~3%之间、生产效率为2.1×10~3~4.1×10~3m^2·h^(-1)、机组前进速度为0.4m·s^(-1)、开沟深度平均值为3cm、开沟深度变异系数为10%、覆土厚度平均值为2.1cm、覆土厚度变异系数为10%。说明该机性能指标满足了设计要求,可为类似机械的研发提供参考。

Effects of 2,4-D and 6-BA on Callus Induction and Plantlet Regeneration from Mature Embryos of Hsien Rice

[ Objective] In order to study the effects of 2,4-D and 6-BA on callus cultivation from mature embryos of hsien rice. [ Method] 2,4-D and 6-BA were set at different concentrations in callus induction and differentiation mediums to study their effects on callus induction, seedling formation and regenerated seedlings rooting. [ Result] In the callus induction medium treated with 0.5 mg/L 2,4-D, the callus induction effects on the varieties like Jiayu 948, Yanghui 559, Yangxian 6547, Zhong＇erruanzhan, Minghui 86, Guanghui 998 and Zunxian 3 were the best; If 0.2 mg/L 6-BA was added into the callus induction medium containing the optimum level of 2,4-D, there was no obvious effect on induction rate of callus, but the differentiation and seedling of callus were inhibited; If the concentration of 6-BA was reduced appropriately in the differentiation medium, the seedling rate of callus would be not only no decreased but increased, meanwhile the quality of regenerated plants would be improved. [ Conclusion] The study results provided some references for the reasonable uses of 2,4-D and 6-BA in callus culture of hsien rice.

风筛式坚果壳仁分选机的研制

坚果破壳后需要获取干净的果仁,依靠人工效率低、成本高,依靠普通筛分法,由于部分坚果破壳后壳仁尺寸比较接近,筛分效果并不理想,本文介绍了项目组研制的一种风筛式坚果壳仁分选机的结构、工作原理、机构及设备特点与试验情况,旨在为坚果破壳后壳仁分选提供一种结构简单,易操作的技术设备。

Transmission Electron Microscopy Observation of Different Callus Structures in Heiya No.14

[ Objective] The aim was to observe the ultrastructure of different callus structures in Heiya No. 14 by transmission electron microscopy. [Methods] Sample preparation and observation were both carried out by conventional transmission electron microscopy. [ Results] It was showed by transmission electron microscopy that the initial callus cells had a large central vacuole, which squeezed its cytoplasm to be a thin layer around the brim of cell, Meanwhile the nuclear was also squeezed to distribute in the corner of cell, but its nucleolus could be still observed; Compared embryogenic callus with initial callus, its cell wall became thick, and many starch grains and chloroplasts including starch grains could be observed in the cytoplasm area of cell membrane; In non-embryoenic callus, no organelles except for the vacuole could be observed; In browning callus, there was almost no organelles in cells. [ Conclusion] There are significant differences in different types of flax callus at the cell ultrastructure level, which can be as an index for reflecting the differentiation ability of callus cell.

Gastroprotective activity of Nigella sativa L oil and its constituent, thymoquinone against acute alcohol-induced gastric mucosal injury in rats

AIM: To evaluate the role of reactive oxygen species in the pathogenesis of acute ethanol-induced gastric mucosal lesions and the effect of Nigella sativa L oil (NS) and its constituent thymoquinone (TQ) in an experimental model.METHODS: Male Wistar albino rats were assigned into 4groups. Control group was given physiologic saline orally (10 mL/kg body weight) as the vehicle (gavage); ethanol group was administrated 1 mL (per rat) absolute alcohol by gavage; the third and fourth groups were given NS (10 mL/kg body weight) and TQ (10 mg/kg body weight p.o) respectively 1 h prior to alcohol intake. One hour after ethanol administration, stomach tissues were excised for macroscopic examination and biochemical analysis.RESULTS: NS and TQ could protect gastric mucosa against the injurious effect of absolute alcohol and promote ulcer healing as evidenced from the ulcer index (UI) values. NS prevented alcohol-induced increase in thiobarbituric acid-reactive substances (TBARS), an index of lipid peroxidation. NS also increased gastric glutathione content (GSH), enzymatic activities of gastric superoxide dismutase (SOD) and glutathione-S-transferase (GST). Likewise, TQ protected against the ulcerating effect of alcohol and mitigated most of the biochemical adverse effects induced by alcohol in gastric mucosa, but to a lesser extent than NS. Neither NS nor TQ affected catalase activity in gastric tissue.CONCLUSION: Both NS and TQ, particularly NS can partly protect gastric mucosa from acute alcohol-induced mucosal injury, and these gastroprotective effects might be induced, at least partly by their radical scavenging activity.

Somatic embryogenesis in wild relatives of cotton (Gossypium Spp.)

Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypo-cotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods.

回家过年,几种情“伤不起”

“叫家过年”，多么温馨的一句话!我们可以从话里感受到那急切的心情、融融的暖意、团倒的幸福和久别重逢的喜悦。

Studies of Improving the Frequency of Indica Rice Transformation by Biolistic Bombardment

In order to improve the frequency of indica rice transformation by biolistic bombardment, suitable culture conditions for embryonic calli,an optimal selection scheme for resistant calli and seedlings, and optimum bombardment parameters a investigated by using 14 commercially important indica rice cultivars. The main results show that the CC medium with 36g/L mannitol is a scheme subculture medium in which the browning of indica rice calli can be mitigated significantly; The concentration of 30～40mg/L Hyg or 150～200mg/L G418 or 10～20 mg/L Basta is suitable for selection of resistant calli; The transformation parameters of 100μg gold powder absorbing 0.2μg DNA per shot and 900 psi helium pressure and 6 cm bombardment distance and bombarded twice for each plate give the best result; Keeping the target calli on osmotic medium containing 60g/L mannitol from 12 ～24h before bombardment to 24～48h after it can increase the efficiencies of transformation . Furthermore, some transgenic indica rice plants are obtained using this optimized transformation system.