夏玉米花丝生长发育动态的研究

以不同穗型的玉米品种为材料,对玉米花丝生长发育动态进行研究.结果表明,花丝的发生首先开始于果穗中下部,其次是基部和中部,顶部花丝出现最晚;花丝出现集中在开始出现后的最初两天.吐丝后第三天生长速率最大.中下部花丝最先抽出苞叶,其次是基部和中部,顶部最晚.前两天的吐丝总量超过50%,尤以第二天吐丝百分率最高.衰亡过程也开始于中下部,基部和中部其次,顶部最晚;每一根花丝从基部开始衰亡,然后向顶部逐渐推移.果穗短粗型的品种花丝发育比较集中、吐丝较快;果穗细长型的品种花丝发育较缓慢,吐丝期延长,发育较晚的顶部花丝不易吐出苞叶。     

气象因子对黄淮海区粒收玉米子粒灌浆与脱水特性的影响

以宜子粒收获玉米品种“浚单1668”为材料,2018～2020年在鹤壁开展子粒灌浆试验,分析子粒灌浆及脱水特性,探讨粒重、子粒灌浆参数和子粒脱水速率与气象因子之间的关系,揭示宜子粒收获玉米产量形成机制。结果表明,不同年份间玉米子粒产量、百粒重和收获时含水率差异显著。玉米产量的差异主要由粒重引起,粒重与灌浆速率显著正相关,与灌浆时间相关性不显著;日照时数和有效积温是影响灌浆速率和粒重的主要气象因子,日照时数和日温差是影响脱水速率的主要气象因子。结果还表明,子粒收获玉米浚单1668吐丝后积温达到769.1～905.0℃·d时,玉米子粒生理成熟,生理成熟时子粒含水量20.67%～25.33%。黄淮海区域玉米生产过程中,通过适时早播,增加吐丝后日照时数和有效积温,玉米获得最大粒重和产量的同时,可有效降低子粒收获时含水量。     

高温胁迫对不同热敏型玉米品种雌雄穗生理特性的影响

以郑单958(ZD958)和先玉335(XY335)为材料,模拟增温处理,探索玉米穗发育对高温逆境生理响应机制。结果表明,高温胁迫下,玉米雄穗、雌穗抗氧化生理在品种及处理间均有较大差异,雄穗细胞中超氧化物歧化酶(SOD)活性呈升-降-升的变化,ZD958雄穗上部小穗SOD活性低于下部小穗,XY335雄穗上部小穗SOD活性高于下部小穗。过氧化物酶(POD)活性在高温处理初期下降,而后持续升高;过氧化氢酶(CAT)活性在高温胁迫初期增加,而后下降甚至低于对照;丙二醛(MAD)含量均呈增加趋势。ZD958雄穗中可溶性糖和脯氨酸含量较高,XY335雄穗中可溶性蛋白含量较高。XY335雌穗SOD、POD和CAT酶活性降低或显著降低,MDA含量较高;ZD958雌穗SOD、POD和CAT酶活性升高或显著升高,MDA含量较低。随高温胁迫持续,ZD958和XY335雌穗中可溶性糖、可溶性蛋白和脯氨酸含量均呈增加趋势,ZD958雌穗具有较高的可溶性糖含量、较高的花丝水势和p H值。     

干旱对玉米花粉、花丝活力和籽粒形成的影响

在玉米植株小穗分化期,小花分化～开花期和灌浆期进行轻度、中度和重度水分胁迫处理,穗生长发育受阻,雌穗比雄穗敏感。小穗分化期干旱几乎没有影响花粉活力;小花分化～开花期干旱花粉活力降低,且主轴小穗花粉活力降低幅度大于已开裂分枝小穗花粉,而未开裂分枝小穗花粉活力受干旱影响较小;雌穗花丝伸长速度变慢,在一定时间内伸出长度较短,数量较少,其活力亦降低。花粉和花丝受干旱影响程度不同,导致减产幅度亦存在差异,以花丝活力受干旱影响较重,减产幅度较大。不同生育时期干旱减产顺序,小花分化～开花期>灌浆期>小穗分化期。不同水分     

强优势玉米杂交种雌穗均一化cDNA文库的构建与鉴定

以强优势玉米杂交种豫玉22发育时期的雌穗为材料构建cDNA文库,为进一步研究和分离杂种优势相关基因构建技术平台。选择玉米雌穗发育过程中的4个时期(生长锥伸长、小穗分化、小花分化和花丝始伸期)的雌穗组织分别构建了4个定向cDNA文库,依据基因组DNA饱和杂交的原理,将从4个独立的cDNA文库中提取的质粒混合,通过基因组DNA亲和体系饱和杂交,获得雌穗全发育时期均一化cDNA文库。该文库平均插入片段1.3kb,含有3×104个克隆。对文库中随机的150个克隆进行测序,81.6%的序列为非冗余序列,11.2%的序列含有两个或两个以上的拷贝,并且主要来自多基因家族转录本,说明此文库的均一化有效。对测序结果进行功能聚类分析,发现文库序列涉及水解酶、转移酶、核苷酸结合蛋白、蛋白激酶、转录因子等基因,涉及环境应答、蛋白代谢、物质转运、个体发育等多个生化途径,说明该均一化文库基因覆盖度较高。该文库还包含有大量的未知基因,有待进一步的发掘和研究。     

利用SMART技术构建荔枝果皮cDNA文库

以新采收荔枝果实的果皮为材料,利用SMART技术构建荔枝果皮cDNA文库。结果表明,初级噬菌体文库滴度为1.1×10^6pfu/mL,重组率为88.1%,文库的插入片段平均长度约为850bp;扩增文库滴度为2.6×10^9pfu/mL。对2444个克隆进行了测序,获得表达序列标签（EST）2136条,平均测序长度562bp。这些EST拼接成为836个簇,含单一序列549条,重叠群287个。初级文库的冗余度为60.8%。     

一个水稻多重颖壳突变体的形态学观察及初步遗传分析

从T DNA插入突变体库中筛选获得1份多重颖壳突变体。解剖镜下观察发现其内外稃伸长,同时伴有类颖壳状结构而普遍呈现多重颖壳。在所观察的215朵颖花中,14.27%的颖花没有雌、雄蕊,23.72%的颖花包含有额外小花,6201%的颖花其雌、雄蕊数目变化分别为1~3枚和1~9枚,部分颖花的花丝基部可看到泡状透明瘤状物;突变体浆片稃片化而使其颖花在自然条件下不能开放;完全雄性和雌性不育。扫描电镜观察揭示其颖花原基分化正常,但进入雌、雄蕊原基的分化较迟,会继续进行类似多重颖壳状器官的分化;同时,颖花原基进行不均衡分裂,产生数目不等的雌、雄蕊。遗传分析显示该突变是一个单基因控制的隐性性状,并与T DNA插入表现共分离。推断它是E类基因引起的功能突变。     

西北春玉米子粒乳线和水分变化与灌浆特性的关系

选择7个不同类型的春玉米品种,通过对灌浆期子粒乳线和含水量、子粒重量的连续测定,明确乳线与子粒水分、子粒水分与授粉后积温的关系,为适宜机械粒收品种筛选提供依据。结果表明,7个参试品种授粉至生理成熟天数、积温需求和百粒重差异明显,灌浆后45 d乳线下移到子粒62.4%～76.2%处,62～70 d乳线先后消失。随着乳线下移子粒含水率呈明显的直线下降趋势,乳线比例可以预测子粒水分和灌浆天数变化,生理成熟后达到低水分粒收要求所需天数在品种间均可相差1倍。参试品种子粒含水率与授粉后积温均符合Logistic Power非线性增长模型。授粉后,7个品种子粒含水率降低到机械收获子粒含水率25%时,各品种所需授粉后积温1 298.6～1 463.2℃·d,平均1 375.7℃·d;达到18%～22%子粒含水率时,所需授粉后积温为1 414.8～1 827.9℃·d。因此,选择生理成熟后脱水快和收获期子粒水分低的品种,延期收获降低水分含量是提高西北春玉米粒收质量的关键。     

可溶性硅和杀菌剂对禾谷镰孢活性影响及田间药效试验

以禾谷镰孢菌为研究对象,在室内测定不同浓度可溶性硅和不同杀菌剂及其互配对禾谷镰孢菌生长的影响。结果表明,可溶性硅浓度越大,对禾谷镰孢菌的抑制率越高,1 666.7 mg/L硅处理后对禾谷镰孢菌的抑制率达30.3%。40%咯菌腈·氟唑菌酰羟胺(0.008 mg/L)对禾谷镰孢菌的毒力最强(EC₅₀=0.008 mg/L),可溶性硅与40%咯菌腈·氟唑菌酰羟胺混配可明显降低对禾谷镰孢菌的抑制率,降幅为8.7%～12.87%;可溶性硅与5%香芹酚按不同比例混配对禾谷镰孢菌互作效应不同;可溶性硅与其他四种杀菌剂混配都能促进对禾谷镰孢菌的抑制。田间药效试验表明,除40%咯菌腈·氟唑菌酰羟胺外,其他5种杀菌剂与硅肥混合喷施防效和产量都高于单喷,其中,混合喷施2 000 mg/L可溶性硅肥+25%吡唑醚菌酯防效最好,增产最高。     

基于SNP标记连锁图谱的玉米花期性状QTL定位

以豫86×豫M1-7构建的RIL群体为作图群体,结合SNP和基因芯片技术对RIL群体进行基因型分析,构建连锁图谱,进行玉米开花期相关性状的QTL鉴定。通过对2年3点玉米开花期相关性状QTL分析,共鉴定到48个开花期性状相关的QTLs,包括18个抽雄期QTLs、16个吐丝期QTLs和14个散粉期QTLs。这些QTLs分别分布在第1、2、3、5、6、7、9、10号染色体上,单个表型贡献率范围在1.67%～20.33%;有一个QTL在3个环境下稳定检测到,3个QTL在2个环境下稳定检测到;有控制吐丝期的qDTS3-1（2018年郑州）和qDTS3-1（2019年郑州）在两个环境下稳定检测到,且贡献率为15.44%和10.12%;一个贡献率达到13.01%的环境性稳定性位点qDTA9-3,可以供分子标记辅助育种选育目标性状。     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).