种子活力研究进展及展望

种子是重要的农业生产资料,高质量的种子对农作物生长和粮食生产至关重要。对种子活力进行了综述,介绍了种子活力形成的物质基础及其与种子活力的相关性、种子活力的影响因素以及种子活力的测定方法。指出了种子活力研究中存在的一些问题,并展望了今后种子活力研究的方向。     

种子活力保持与提高的影响因素与对策

种子活力是种子播种质量的重要指标,也是种用价值的主要组成部分。介绍了种子活力及其影响因素,综述了保持和提高种子活力的对策,并展望种子活力研究方向。     

不同活力等级的箭筈豌豆种子吸胀期间的某些生理生化差异

前言关于种子活力的研究,已日益引起人们的重视,认为“活力”的概念,能更正确地反映种子本身的健康程度和播种质量。因此,近年来围绕种子活力问题,开展了一系列生理生化研究,发展了许多测定方法。     

种子活力无损检测方法研究进展

种子活力作为衡量种子质量的一个重要指标,对农业经济的发展有着重要影响。传统的种子活力检测方法因其检测时间长会对种子造成不可恢复性的损伤等缺点,难以满足现代种子快速、无损生产的新要求。而新型种子活力无损检测技术采用非接触式检测,不会对种子造成物理或化学损伤,且检测效率高,是未来种子活力检测的主要方法。本文针对目前种子活力检测现状,总结了近年来应用于种子活力检测的无损检测技术,并对种子活力检测技术的未来发展趋势及方向进行了展望。     

种子活力的生物学基础及提高和保持种子活力的研究进展

种子活力是种子生理学的一个重要领域。近年来，有关种子活力的研究取得很大进展。本文从种子活力的概念、性质，影响种子活力的因素和种子活力的分子生物学基础，以及目前采用的或正在研究的提高和保持种子活力的措施等方面进行简要综述。     

种子活力研究进展

种子活力是种子生理学的一个重要领域。近年来，有关种子活力的研究取得很大进展。文章从种子活力的概念、影响种子活力的因素和种子活力的分子生物学基础．以及目前采用的或正在研究的提高和保持种子活力的措施等方面进行简要综述。     

种子处理技术在提高种子活力上的应用

种子活力的高低是由种子的遗传特性及其发育形成过程中的条件所决定的。种子的成熟度、成熟过程中的外界条件及收获、运输、贮藏过程中的环境条件都会影响种子活力的表达。有关种子活力的各种影响因素及保持种子活力的方法已有大量的研究报道,并在生产上得到了应用。但由于成熟和收获过程中不良     

积极开展种子活力研究的建议

种子活力,已成为种子学领域里的一个新兴热门。近二十多年来,国外开展了大量工作。许多国家都把种子活力问题列为他们农业科研的重点课题。在历届国际种子协会(ISTA)年会上都设有活力的专题讨论,并在ISTA机构内设立活力委员会。美国种子     

蚕豆种子贮藏过程中遗传完整性变化和麦类陈旧种子PEG渗调后的胚培养

本文研究了温度、种子含水量和包装材料等贮藏因素对蚕豆种子活力的影响及种子遗传完整性变化,特别是对种子活力高低与细胞亚结构的变化进行了探讨。并研究了提高陈旧麦类种子活力的一种简便有效的胚培养方法。     

小麦种子活力的影响因素与控制及种子贮藏技术

种子活力是种子质量状况的一个重要指标,小麦种子的后熟作用、含水量以及环境的温湿度是影响小麦种子活力的主要因素;针对江苏地区提出了小麦种子活力的控制技术与种子贮藏技术.     

Effect of Intercropping on the Yield Components of Rice, Mungbean, Soybean, Peanut and Blackgram

An experiment with sixteen cropping systems (pure and intercroppings) was conducted during the kharif season of 1985 and 1986. The sixteen cropping systems were: sole rice, sole mungbean, sole soybean, sole peanut, sole blackgram, rice + mungbean (2:1), rice + mungbean (4:1), rice + mungbean deferred (2:1), rice + soybean (2:1), rice + soybean (4 : 1), rice + soybean deferred (2 : 1), rice + peanut (2:1), rice + peanut (4 : 1), rice + blackgram (2:1), rice + blackgram (4:1) and rice + blackgram deferred (2:1). Sole crop of rice always recorded higher number of effective tillers/m², however, it was observed that legumes had an influence on the number of filled grains per panicle and thousand grain weight of rice in rice + legume combinations. Among legumes, pure crops of soybean and peanut always gave rise to increased number of yield components than the other crops grown in association with rice. In case of mungbean, number of pods per plant and thousand seed weight was higher in pure crops though number of seeds per pod was more with rice + mungbean combination. Deferred sown blackgram in association with rice yielded greater number of seeds per pod and thousand seed weight though sole crop of blackgram significantly produced higher number of pods per plant.     

花生AhLEA18蛋白基因的克隆与表达分析

LEA蛋白家族是一类在种子胚胎发育晚期丰富表达的蛋白,在种子的正常发育过程中大量积累,同时在植物处于干旱、寒冷、盐胁迫等逆境条件下高水平表达,推测该类蛋白在缺水条件下具有一定的生理保护功能。根据蛋白序列特点,该蛋白家族分为多个组,LEA18蛋白属于其中一组蛋白。PvLEA18蛋白在干燥种子、花粉粒中大量积累,也参与到对水分缺失、ABA处理的生理应答过程过程。本研究从栽培种花生鲁花14中克隆得到一个LEA18基因,命名为AhLEA18。对其序列的生物信息学分析表明,AhLEA18具有典型LEA18蛋白序列特征。通过半定量RT-PCR的方法对该基因在花生植株不同组织及不同发育时期的种子中的表达情况进行了分析。     

反义TRX s基因对转基因小麦籽粒硫氧还蛋白还原活性的影响

以转反义TRX s基因小麦纯合系为材料,分析了转基因小麦TRX h活性和清蛋白、球蛋白、谷蛋白和麦醇溶蛋白各组分及其还原状态的变化。结果表明,不同成熟期转基因小麦籽粒和胚乳中TRX h活性平均比对照降低76.2%和14.2%,其籽粒中的清蛋白、球蛋白、麦醇溶蛋白和谷蛋白巯基含量平均比对照分别低41%、44%、14%和13%,胚乳中分别     

花生籽仁抗黄曲霉菌生理生化机制研究进展

花生是最易受黄曲霉菌侵染的作物之一。为进一步阐述花生籽仁抗黄曲霉侵染的生理生化机制,前人已从受黄曲霉侵染的花生籽仁中分离提取出多种能直接抑制黄曲霉生长或分生孢子形成的物质。本文综述了花生籽仁中发现的抗黄曲霉物质及花生籽仁受黄曲霉侵染后酶活性的变化。目前花生籽仁中发现的抗黄曲霉物质从成分上可以分为多酚类物质和抗菌蛋白。同时,研究指出苯丙烷类代谢通路及活性氧代谢通路可能参与花生抵抗黄曲霉侵染、定殖及产毒的过程。近年来,随着多组学技术的发展,更多具有抗黄曲霉活性的物质将被发现和验证,以发掘更多抗黄曲霉花生种质资源及基因资源。     

花生膜联蛋白基因家族成员的结构和表达分析

植物膜联蛋白(annexin)是一类钙依赖性磷脂结合蛋白,参与调控植物代谢和生长发育并协同调节抗旱、耐盐等多种抗逆反应,其结构在不同植物中具有物种特异性。为系统分析花生膜蛋白基因家族,对30个花生annexin(annexinof Arachis hypogaea, AnnAh)基因进行了生物信息学分析。结果表明30个AnnAhs不均匀分布在13条染色体上,其中A、B基因组中各有13个和17个。AnnAhs含有2～8个内含子,但大多数含有5～6个内含子。聚类分析表明,植物annexin聚类关系比较复杂,低等植物、单子叶、双子叶植物annexin间隔分布, AnnAhs穿插其中,分布于各个分支中;但在各个小分支中,AnnAhs基本上都与双子叶植物annexin聚在一起,其中与大豆、苜蓿、向日葵亲缘关系较近,其次是拟南芥;但个别AnnAhs与单子叶植物和低等植物annexin聚在一起。30个AnnAhs均无跨膜结构域,其中有16个AnnAhs定位于细胞质,其余定位不明确。对AnnAhs可变剪切分析显示,仅有11个发生可变剪切事件,占38%;根中发生的最多,其次是叶中,种子中最少。根据表达谱数据分析发现, AnnAhs在seed2和根中表达量较高,其次是seed1,在叶中表达量较低。本文可为花生抗性育种提供一定的理论支撑。     

Genetic characterization and gene flow in different geographical-distance neighbouring natural populations of wild soybean (Glycinesoja Sieb. & Zucc.) and implications for protection from GM soybeans

To design appropriate strategies for ex situ and in situ conservation of wild soybean and safeguard the biosafety of the wild soybean gene pool when genetically modified soybeans are grown, it is important to understand its genetic characteristics, and to quantify gene flow and kinship within and between neighboring populations. We analyzed 9 pairs of neighboring populations of wild soybeans using 20 pairs of nuclear SSR markers. Results showed that Chinese wild soybean natural populations had outcrossing rates of 0–3.5% and that most populations contained many kinship families. The kinship families could be attributed to the accumulation of outcrossed offspring within populations during the history of population colonization. Wild soybean is very sensitive to environmental selection, which results in genetic differentiation of populations, and the emergence of specific alleles. We used an index τ to explain why genetic differences would exist between the pairwise populations; the interpopulation genetic differentiation chiefly consisted in the differences of allele frequencies over the genome. We found long-distance dispersal (1.5 km) of wild soybean seeds in a land ecosystem. There was close correlation between genetic and geographical distance among natural populations of Chinese wild soybean. Within a distance of 50 km, there was greater gene flow when the distance between populations was shorter. These findings have implications for ex situ and in situ conservation in an ecogeographical region, and also for protection of the gene pool from contamination by GM soybeans in wild soybean species.     

Comparative analysis of different methods revealing the involvement of proteins during ageing of rice seeds

Seed longevity is a very important characteristic controlling seed quality. However, the mechanism underlying this characteristic is poorly understood. In this study, 'FH7185', a storable rice variety, the germination rate of which was 66.63%, much higher than the control after artificial ageing under relative humidity 88% and 42°C for 21 days. Different methods were applied to reveal the involvement of proteins during ageing of rice seeds. In total, 35 differential proteins were identified from 2D‐PAGE, and 3,719 proteins from iTRAQ analysis. A comparison of these two methods showed that not all protein types could be detected on the 2D‐PAGE gels, and the dynamic range was somewhat limited. So the comprehensive proteome map from the iTRAQ analysis was used to identify the quantitatively regulated proteins that played roles in seed longevity, and found that the most marked change was the increased abundance of many metabolic enzymes, especially the ones involved in α‐linolenic acid metabolism in the embryos during ageing. OsLOX2 and OsLOX3 had a negative effect on seed longevity, which were lower in FH7185 than the control. The dehydrogenase (LOC_Os07g44430) which played a major catalytic role in lipid peroxidation, also changed significantly during ageing. Therefore, OsLOX2, OsLOX3 and Loc_OS 07G44430 may be involved in the regulation of seed longevity with a synergistic effect.     

蓝茎冰草种子劣变过程中生理生化变化

研究蓝茎冰草（Pascopyrum smithii）种子在自然和人工老化过程中生理生化变化。结果表明：在自然和人工老化过程中，发芽率和活力指数下降，活力指数的变化先于发芽率，是反映种子质量的敏感指标；蓝茎冰草种子电导率与种子生活力及活力正相关；氨基酸泄漏与种子中游离氨基酸含量正相关，不反映种子膜的透性；蓝茎冰草种子中可溶性蛋白质含量随着人工老化而上升。     

枇杷种子脱水敏感性的初步研究

枇杷（EriobotryajaponicaL.）种子成熟采收时含水量高达58.7％，其中子叶含水量为55.3％，胚轴的含水量为73.2％。新鲜种子的发芽率和活力指数分别为90％和0.81。轻度脱水能较大幅度地提高发芽率和活力指数。但随着脱水程度的不断加深，子叶和胚轴的超氧物歧化酶（SOD）活性下降，丙二醛（MDA）含量和种子浸泡液的电导率增加，种子活力迅速降低。当子叶和胚轴的含水量分别降至35.5％和28.0％时，种子发芽力完全丧失。枇杷种子脱水敏感的一个重要原因就是在脱水劣变过程中，发生了膜脂过氧化作用，从而使膜脂含量下降，膜结构和功能受损，最终导至种子活力丧失。     

Seed number responses to extended photoperiod and shading during reproductive stages in indeterminate soybean

The number of seeds per unit land area, the major yield component in soybean (Glycine max (L.) Merrill) is largely determined after the beginning of flowering, particularly from R3 to R6. Environmental factors increasing crop growth rate (e.g. radiation) or extending the duration of the reproductive phases (e.g. photoperiod) increase the number of seeds. We aimed to compare the mechanisms by which photoperiod and radiation affect the definition of final seed number during the critical period of R3–R6. Two field experiments were conducted with indeterminate soybeans at intermediate maturity group. All plots in each experiment were grown under natural conditions until the beginning-pod stage (R3); and from then onwards different treatments were imposed. Treatments consisted of the factorial combination of two levels of radiation (natural or shading) and two photoperiod regimes (natural or extended). Extended photoperiod increased the duration of reproductive phases, the number of nodes and the number of pods produced on the nodes that flowered during or after the applications of the treatments. Shading had negligible effects on development and node number, but reduced crop growth rate and also reduced the number of pods produced on most nodes of the plants. The number of seeds was positively related to the crop growth rate during R3–R6, but photoperiod increased the number of seeds produced per unit of crop growth rate, due to the lengthening of the phase. The number of seeds was therefore even better related to accumulated growth during R3–R6, irrespective of the factor that increased the accumulated biomass (higher daily radiation or longer duration of the phase) suggesting that long photoperiods increased the number of pods and seeds established per unit land area, mainly through increasing the total resource availability during a phase that is critical for the determination of seed number in soybean. However, photoperiod regulation involved additional changes in the development, evidenced by changes in the pod distribution pattern within the canopy.