Soybean Seed Aging and Environmental Factors on Seedling Growth

The effect of seed vigor on seed emergence depends on the type of environmental stress present at the time of seed germination and establishment. Therefore, the aim of this study was to assess the interaction of environmental stresses and aging on soybean (Glycine max L.) seed emergence. A factorial arrangement of treatments imposed on a randomized complete block design with four replications was conducted. Treatments of seed aging for 12, 24, 36, and 48 h at 41°C, salinity (6 and 12 ds/m²), water deficiency (–4 and–9 MPa), and sowing at depths of 3 and 7 cm were selected. Growth measurements were completed 21 and 55 days after planting. Analysis of variance was performed using the regression method for quantitative treatments such as seed aging, and if interactions were significant, interaction slicing was utilized and means compared with least significant difference tests (0.05). For quantitative treatments, regression analysis was conducted and path analysis was performed on growth traits. Results showed that aging had a significant effect on maximum emergence and rate of emergence. The ranking of the stress factors from most to least injurious for maximum emergence were severe salinity, severe drought, medium salinity, sowing depth of 7 cm, and medium drought. Harmful stress conditions on the plant leaf area and seedling dry weight were severe salinity, medium salinity, severe drought, medium drought, and sowing depth of 7 cm (only for seedling dry weight). Relative growth rate, net absorption rate, and leaf area ratio were not affected by aging but were affected by environmental conditions. These findings indicate that the impacts of environmental conditions are at least partially controlled by seed vigor.     

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.     

种子老化及活力修复研究进展

种子是一种重要的物质生产资料,对农牧业的生产发展以及种质资源的保存起着不可替代的作用,研究种子老化生理变化及提高种子活力的方法对实际生产具有指导意义。本研究主要概述了种子老化的现象,从种子萌发情况和种苗生长状况、酶活性、呼吸和能量系统、贮藏物质、核酸和蛋白质合成能力、细胞结构及膜透性、有毒有害物质积累等方面阐述了种子老化过程的生理生化变化,分析比较了引发技术处理、干湿处理、营养元素处理和植物生长调节剂处理等修复和提高种子活力的措施,并对种子活力与老化生理机理的研究方向与发展趋势做出了展望。     

黑茶陈化机制研究进展

对黑茶陈化的相关研究进行综述,重点阐述了"陈化"对黑茶感官品质及主要品质成分的影响。随着贮藏时间的延长,在水分、氧气、光照、温度条件和微生物作用等因素的共同影响下,黑茶的感官品质表现出一定的变化规律。主要品质成分、香气成分在陈化过程中均发生不同趋势、不同程度的变化,在一定时间范围内黑茶的品质得到提高和改善,具有"越陈越香"的趋势。深入研究黑茶陈化的实质,对于促进黑茶理性消费、黑茶市场健康发展具有积极意义。     

人工老化和修复处理对小麦种子活力及生理特性的影响

种子在贮藏过程中,会出现老化现象,使种子活力下降,生理特性发生改变.本实验采用高温高湿(T=52.3℃,RH=80％)人工老化方法处理小麦种子,并以500 mg/L抗坏血酸(AsA)、20％聚乙二醇(PEG) 6000、500 mg/L赤霉素(GA3)3种溶液进行老化种子的修复,人工老化及修复后的种子经室内发芽试验,分别测定种子发芽指标、种子活力、过氧化物酶(POD)活性、丙二醛(MDA)含量变化情况.结果表明,经人工老化处理后,小麦种子的发芽势下降2.27％,发芽率下降2.67％,种子活力(TTC还原强度)下降7.29％,这三者虽都有所下降,但未达到显著水平(p＜0.05);而老化种子的活力指数和发芽指数下降显著,分别较未老化处理种子下降35.86％和51.51％.PEG修复处理能显著提高老化种子的发芽指数;GA3修复处理对老化种子活力指数的修复效果最好;AsA和GA3修复处理使老化种子的MDA含量显著降低,但未达到未经处理种子的MDA含量水平;PEG、GA3和AsA修复处理对POD酶活性都有一定程度的提高,但影响不显著.     

生物炭陈化的研究进展

有关生物炭短期效应的研究已很多,然而对于生物炭长期效应的研究还缺乏理论基础,尤其是对于生物炭陈化的研究成果更少。综合国内外现有生物炭陈化研究成果,总结生物炭陈化方法,分析陈化处理对生物炭理化性质的影响,探索陈化生物炭施入对土壤性质的影响机制,阐明现有生物炭陈化研究方法的不足,提出未来生物炭陈化研究的发展方向,以期对生物炭陈化的研究具有参考意义。     

低排放机械调控法对片烟养护醇化的影响

为探索片烟在低排放机械调控法养护下的最佳醇化期,研究了低排放机械调控法对不同等级烟叶的醇化效果。结果表明,低排放机械调控法养护醇化的烟叶外观质量、感官质量评价均优于常规自然养护,更有利于烟叶化学品质的转化和烟叶内含物的醇化;低排放机械调控法后期充氮气能抑制烟叶过度醇化,相对延长烟叶最佳使用周期。     

农村劳动力老龄化对粮食生产的影响研究

在人口老龄化趋势不断加快的背景下,我国农村劳动力也不可避免地呈现老龄化态势。农村劳动力的老龄化导致农业适龄劳动人口的减少,甚至不足,给农业发展带来了巨大的困难和挑战。在全国粮食总产量实现"十年增"的情况下,农村劳动力老龄化却一直威胁着粮食生产。本文分析了劳动力老龄化对粮食生产的影响,并提出了相关的建议。     

大豆种子抗老化鉴定的方法研究

选用遗传差异相对较大的皖豆24、皖豆25(杂交品种)及合豆3号的种子,在温度为40℃、湿度为85%的条件下老化处理4、8和12 d,研究加速老化过程中不同基因型大豆种子成苗率、发芽率、电导率及单株幼苗干重的变化规律。结果表明:随着加速老化时间的延长种子活力下降;加速老化处理8 d,3个品种的各项鉴定指标均发生改变:品种的成苗率、发芽率及单株幼苗干重显著降低,电导率明显升高,且品种间有显著差异;发芽率和成苗率的变化在品种间具有一致性,电导率、单株幼苗干重的变化和成苗率品种间一致性较差;成苗率和发芽率的相关性最高(r=0.972**)。利用国家大豆微核心种质中的91份资源对老化鉴定方法进行验证,结果在温度为40℃,湿度为85%条件下老化8 d的种子发芽率及老化指数与在自然条件下老化15个月的发芽率及老化指数极显著相关(r=0.943**,0.716**)。综合分析认为,温度为40℃,湿度为85%条件下老化处理8 d,以种子发芽率为活力鉴定指标可作为大豆种子抗老化性的鉴定方法。     

4个玉米品种种子耐老化能力的模糊隶属函数法分析

以农大108、中农大4号、先玉335和郑单958玉米种子为试验材料,研究其人工老化后的生理特性和萌发特性,采用模糊数学隶属函数法综合评价其耐老化能力。结果表明,随着老化时间的延长,4个玉米品种的种子浸出液电导率和MDA(丙二醛)含量增加,脱氢酶活性、发芽率、发芽势、发芽指数和活力指数降低。通过模糊隶属函数法综合评价分析,4个玉米品种的耐老化能力为郑单958>先玉335>中农大4号>农大108。