6种番荔枝属果树雄蕊特性的研究

采用显微观察法研究6种番荔枝属果树的雄蕊特征,观测不同种的雄蕊长度、数量、花药长度和花粉数量及形态大小等雄蕊特征。结果表明:雄蕊特征随树种的不同而有变化,但普通番荔枝、阿蒂莫耶番荔枝、秘鲁番荔枝、牛心番荔枝等4种番荔枝的雄蕊特征及变化基本一致,而与山刺番荔枝、圆滑番荔枝等相差甚远;山刺番荔枝和圆滑番荔枝的一些雄蕊特征则较为接近。此外,尽管花药长短相差大,但每个花药内花粉数量的差异不显著,表明每朵花的花粉量仅由雄蕊数决定。     

芥菜型油菜不育系柱头外露性与不育性的关系

芥菜型油菜不同来源的不育系柱头突出营外长度及花粉活力研究表明，所观察的不育系柱头均突出蕾外，但突柱的长短与不育性无显著相关。无论柱头突出长或短，它们均表现雄蕊退化，花粉败育，有生活力花粉数量很少且不萌发。     

8个菠萝品种的花粉特性及其离体萌发

研究8个菠萝品种的花粉特性以及离体条件下的花粉萌发。结果表明:不同菠萝品种的花粉大小、花粉数量、花粉活力、花粉离体萌发率和花粉管萌发长度均存在明显差异。金菠萝花粉最大,金钻花粉最小;单个花药花粉量约3~18万粒,蜜宝花粉量最多,苹果花粉量最少。用TTC法测定8个菠萝品种的花粉活力为25.18%~56.84%,其中无刺卡因最高,黄金菠萝最低。在离体培养条件下,不同菠萝品种在9种培养基上的花粉萌发率均值和花粉管长度均值变幅分别为53.31%~76.02%、43.27~518.28μm,其中蜜宝、无刺卡因、甜蜜蜜、金菠萝的花粉萌发率均值和花粉管长度均值较高,珍珠、苹果的花粉萌发率均值和花粉管长度均值较低。配方为1%琼脂+10%蔗糖+0.01%硼酸的培养基适于用作菠萝花粉的离体萌发培养基。     

山茶属3种植物花药超低温保存研究

为有效保存山茶属植物的花粉,以茶梅(Camellia sasanqua)、攸县油茶(Camellia yuhsienensis Hu)和多齿红山茶(Camellia polyodonta How)成熟花药为试材,对不同干燥处理的花药进行超低温(液氮,-196℃)保存和水浴解冻的研究。结果表明:不同干燥时间及不同预冻方式对超低温保存后3种山茶属花粉的萌发率有显著影响。茶梅花药经30℃干燥处理4h,含水量为26.92%时,超低温保存后花粉活力最高;攸县油茶花药经30℃干燥处理2~4h,含水量为27.52%~33.71%时,超低温保存后花粉萌发率最高;多齿红山茶花药经30℃干燥处理1~3h,含水量为20.98%~37.95%时,超低温保存效果最佳。3种花药经-26℃预冻处理,超低温保存后花粉萌发率显著高于4℃处理和不预冻处理的对照;超低温保存后38℃(2min)水浴解冻效果最好。3种植物新鲜花药在室温下干燥保存20~40d,花粉活力基本丧失。而经超低温保存半年,3种花药花粉仍具较高的活力,甚至超过保存前的水平。     

罗布麻花粉萌发及保藏方法的研究

1、罗布麻花粉在蔗糖和葡萄糖培养基上均有较高的萌发率，在5％蔗糖和5％葡萄糖培养基上萌发率最高，分别为95．6％和97．8％；花粉管长度也最长，分别为146．4微米和156．2微米。适量的硼酸和氯化钙对花粉萌发和花粉管生长均有促进作用。2、罗布麻花粉在适宜的萌发条件下，一般在播后20～30分钟开始萌发。葫发后15～30分钟内花粉管生长最快，约56．1微米，以后逐渐减慢。90分绅后花粉管生长趋于停止。3、开花前三天的花蕾(花药未开裂)，其花粉不能萌发。开花后第二天的花朵，其花粉萌发率最高，达97．6％；花粉管长度也最长，达187．3微米。4、花粉保藏日期长短因保藏条件而异。一般在低温、干燥环境中保藏花粉效果较好。     

不育系柱头和恢复系花粉生活力的观察

使用ＣＯ２诱导水稻颖花整齐地开放，去除不育系未开颖以及柱头来外露的颖花，授粉于外露柱头，以其结实率来衡量柱头活力；定时将裂药后的花粉散落于马铃薯培养基上，镜检花粉的发芽率。结果表明；不育系颖花外露柱头的生活力能维持３一４天，但以当天和第二天的活性为最高；恢复系开花后残留在花药中的花粉萌发力仍能维持３小时之久。     

龙眼2个品种花部特征比较研究

研究龙眼石硖和储良2个品种的花部形态、开花生物学特性、花粉形态特征及萌发率、花粉量、P/O值、柱头可授性及其黏液分泌情况。结果显示，二者花部特征相似，储良花期较石硖长；二者的花粉形态相似，储良的花粉较石硖稍大，萌发率较石硖高；P/O值说明龙眼为专性异交植物；石硖和储良花粉活力和柱头可授性是同步变化的，尤其在盛花期花粉活力趋于最大，柱头分泌黏液与柱头可授性变化也一致，都在柱头展开成水平，开花约48 h达到最大。     

紫毛野牡丹种子萌发的研究

观察紫毛野牡丹种子的形态特征并测定其基本参数。结果表明：紫毛野牡丹种子的萌发需要光照条件,全黑暗条件下种子发芽受到限制;低浓度（0-20 mg.L-1）的6-BA可提高紫毛野牡丹种子的发芽率和发芽势,浓度为10 mg.L-1时,效果最为显著。IAA抑制紫毛野牡丹种子的萌发,在一定范围内,发芽率随着IAA浓度的提高而降低。     

台湾甘蔗种子发芽力影响因素的研究概况

台湾糖业研究所对甘蔗种子的发芽力开展了一系列研究，结果表明，甘蔗双亲花穗的花粉数量多，产生的种子发芽力就高；高压法养茎产生的种子发芽力高于亚硫酸法；随着冷藏时间的延长，甘蔗种子的发芽力逐渐降低；甘蔗花穗中的种子越重，萌发的实生苗就越多。     

澳系睡莲花粉离体萌发及低温保存研究

为研究适宜睡莲花粉离体萌发的培养基和低温保存的方法,以睡莲品种‘默笙’和3份原种睡莲的花粉为试验材料,采用单因素、正交试验设计,筛选出最适宜的培养基,观测睡莲花粉在不同温度下保存的萌发率。结果表明,4种澳系睡莲花粉的最适培养基的各组分浓度不同,花粉的生活力存在差异,澳洲原生浅色睡莲与澳洲原生深色睡莲的花粉生活力较高,分别为43.90%和45.63%;‘默笙’睡莲的花粉生活力次之,为31.84%;‘白巨睡莲’的花粉生活力较低,为9.73%;4种澳系睡莲花粉均不耐贮藏,不同温度下保存72 h后萌发率均为0。本研究结果可为睡莲杂交育种的亲本选择、花粉的低温保存研究提供参考。     

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.     

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.     

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.     

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).