Effect of Aspergillus oryzae-challenged germination on soybean isoflavone content and antioxidant activity

Application of microbial stress to soybean during germination induces the accumulation of phytoalexins, which have many health benefits. In this study, the effects of stress induced by Aspergillus oryzae on the phytochemical composition of germinating soybeans were investigated, and their radical scavenging activity was compared with those of ungerminated (US) and germinated (GS) soybeans. Additionally, the antioxidant activity of coumestrol, a soybean phytoalexin, against hydrogen peroxide-induced reactive oxygen species (ROS) was investigated in HepG2 cells. A. oryzae exposure significantly decreased the total isoflavone content and induced coumestrol and glyceollin I. A. oryzae-challenged germinated soybeans exhibited the highest radical scavenging activity (IC(50) = 0.55 mg/mL) as compared to US and GS. Coumestrol exhibited significantly higher radical scavenging activity than daidzein and genistein. Furthermore, coumestrol significantly prevented hydrogen peroxide-induced ROS production and lipid peroxidation and inhibited decreases in cell viability, intracellular glutathione (GSH) levels, and superoxide dismutase (SOD) activity. These results indicate that using food-grade A. oryzae to elicit the biosynthesis of phytoalexins alters the secondary metabolite profiles of the soybeans and offers enhanced bioactivity of soybean as a functional food ingredient.     

马铃薯在分离筛上运动规律的试验研究

对马铃薯相对分离筛的运动规律进行了试验研究。将马铃薯在分离筛上的运动划分为碰撞运动与相对滚动两种运动形式,在碰撞理论与定常理论的基础上,利用高速摄像技术分析了马铃薯在分离筛上的运动规律,并在田间试验得到验证。试验结果表明:马铃薯与分离筛的碰撞恢复系数随着筛面倾角的增大而增大;马铃薯在分离筛上向后滚动的最大加速度随曲柄转速的增大而逐渐增大;相同曲柄转速时马铃薯在分离筛面上的向后运动为加速运动;随着筛面倾角的增大,马铃薯向后滚动的最大加速度和前后滚动距离均增大。     

油菜直播机组无人播种作业远程监测系统设计

为解决油菜直播机组无人播种作业过程中田间播种质量信息难以实时直观展示的问题,本研究以雷沃804拖拉机及其搭载的2BYQ-8型气送式油菜直播机为试验平台,设计一套油菜直播机组无人播种作业远程监测系统。该系统由油菜直播机组无人播种作业平台、无人播种作业数据采集系统和播种质量监测云平台三部分构成,通过对雷沃804拖拉机档位、离合、动力输出装置（power take off,PTO）、悬挂机构进行电控液压改装,设计相应控制策略实现直播机组的无人播种作业;利用车载路由器组建播种监测终端和车载计算机之间的局域网,实现对播种数据与导航数据的融合同步,并通过网络连接传输给云平台进行数据存储与实时展示;云平台计算播种质量数据及其对应的田间位置数据,基于网页端高精度地图生成田间作业区域的播种状态图。结果显示,直播机组无人播种作业段横向平均偏差0.037 m,最大偏差0.125 m,电控液压改装系统运行稳定、可靠,满足直播机组无人作业要求,4G网络条件下,云平台通信最大数据传输时延不超过100 ms,云存储数据完整无遗漏,各播种通道田间播量检测准确率不低于96.16%,满足远程监测系统实时性和准确性要求。研...     

术前饥饿处理对马氏珠母贝血淋巴免疫机能的影响

在室内养殖条件下研究了术前限食处理对马氏珠母贝血淋巴细胞密度、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、溶菌酶(LSZ)、酸性磷酸酶(ACP)和碱性磷酸酶(AKP)活性的影响。实验设置每天投喂一次和两天投喂一次两个处理组,每天投喂两次为对照组,分别在实验开始和第1、2、3和4周取样检测血淋巴免疫功能。结果显示:限食1周后,马氏珠母贝血细胞密度、SOD、CAT、LSZ、ACP和AKP等酶活性均随限食程度的增加呈下降趋势,2个限食处理组的免疫参数较对照组明显下降,并表现出显著性差异(P0.05),两天投喂一次处理组的各项免疫机能均显著低于对照组,且这种趋势一直延续至第4周。据此推断,限食可以显著降低插核手术贝的生理机能和免疫活性,为马氏珠母贝育珠术前处理提供理论依据。     

马铃薯硒营养强化技术研究进展

硒是人体必需的微量元素,马铃薯是世界上第4大主粮作物,施用硒肥是生产富硒马铃薯的主要途径。本文介绍了马铃薯硒营养强化技术研究进展,阐述了硒在马铃薯植株内的一般累积分布规律,硒肥对马铃薯生长发育、产量和品质的影响;介绍了马铃薯生长过程中硒营养强化的生理遗传机制等内容;总结了近年来马铃薯富硒栽培技术和新型肥料研发情况;指出绿色环保、低廉高效的生物有机硒肥、缓释硒肥将是未来的发展方向。     

菊叶薯蓣茎段组织培养研究

为解决菊叶薯蓣种苗的繁育问题,用不同种类、浓度的植物生长调节剂对菊叶薯蓣幼嫩茎段进行离体培养试验,结果表明,启动培养用M S 6-BA 0.2m g/L KT 1.0m g/L NAA 0.01m g/L诱导不定芽萌芽率为100%,效果最理想;继代培养用M S 6-BA 0.8m g/L NAA 0.2m g/L诱导芽的增殖系数超过3,长势较理想;生根培养用1/2M S IBA 1.5m g/L NAA 0.3m g/L诱导生根长苗率达90%以上,对生根培养的效果最佳;采用河沙 塘泥假植菊叶薯蓣组培生根苗成活率高,生产成本降低;表明应用组培快繁技术能为菊叶薯蓣的规模化种植提供充足的优质种苗。     

Probing of an environmentally friendly regenerated cellulose material having bimorphic behavior

Novel regenerated cellulose material which was prepared from cellulose acetate fiber through the hydrolysis of acetyl groups have been developed by an environmentally friendly process without emitting toxic substances in addition to be at low production cost. They have composite crystalline structure constituted of cellulose II and cellulose IV. Also, they show a lamellar morphology with an increased amorphous region, as compared to conventional regenerated cellulose such as viscose rayon and cupra rayon. Our data obtained by several independent methods demonstrated that the adsorption properties of cellulose fibers depend predominantly on the amorphous region.     

Intermittent drainage in paddy soil: ecosystem carbon budget and global warming potential

Intermittent drainage of rice fields alters soil redox potential and contributes to the reduction of CH₄ emission and thus may reduce net global warming potential (GWP) during rice cultivation. Incorporation of green biomass helps maintaining soil organic matter, but may increase CH₄ emission. We investigated net ecosystem carbon budget (NECB) and net GWP under two water management regimes—continuous flooding and intermittent drainage—having four biomass incorporation levels (0, 3, 6 and 12 Mg ha^?1). Water management and biomass incorporation level demonstrated significant (P < 0.05) interaction effect on the NECB and GWP. Intermittent drainage decreased the NECB by ca. 6–46 % than continuous flooding under same rates of cover crop biomass (CCB) incorporation. Moreover, intermittent drainage reduced seasonal CH₄–C fluxes by ca. 54–58 % and net GWP by 35–58 % compared to continuous flooding. There was also no significant reduction in rice yield because of intermittent drainage under similar CCB. This implies that incorporation of 3 Mg ha^?1 CCB and intermittent drainage could be a good option for reducing net GWP and higher grain yield.     

橡胶树胶孢炭疽菌组蛋白乙酰转移酶CgGCN5调控致病力功能研究

胶孢炭疽菌引起的炭疽病害是造成海南省橡胶减产的主要原因之一。研究该病原菌致病力的分子机制能够为新型防控策略的研发提供理论依据。在橡胶树胶孢炭疽菌中,存在1个编码组蛋白乙酰转移酶的基因CgGCN5。在本研究中,通过同源重组原理及原生质体转化法构建了橡胶树胶孢炭疽菌CgGCN5的敲除突变株和互补菌株,并对其生长、产孢及致病力等表型进行了初步分析。结果表明,与野生型菌株相比,CgGCN5敲除突变株的生长速率、产孢能力均显著下降;并且突变株对橡胶树叶片的致病力也显著下降;进一步分析表明,突变株丧失了对玻璃纸的穿透力。与此同时,互补菌株能够恢复突变株的相应表型。以上结果表明,CgGCN5在调控胶孢炭疽菌的生长及致病力中起重要作用。