两组玉米近亲交配杂种优势和配合力的分析

通过对两组共8个部分近亲玉米自交系主要农艺性状杂种优势和配合力的分析,结果表明:9个性状的一般配合力差异显著或极显著;而特殊配合力方差,Ⅰ组的百粒重和穗位高、Ⅱ组的所有性状差异极显著;两组的杂种优势表现十分相似,从大到小的排列次序完全相同,其中单株产量最高,而行粒数最小。     

九个豫育玉米自交系配合力分析及评价

采用Griffing Ⅳ设计,对河南省近年育成的9个玉米自交系的单株产量等13个性状的配合力进行了分析.结果表明:除了出籽率GCA、SCA及穗粗和粒厚的SCA外,其它各性状配合力在9个自交系间存在显著或极显著差异.以单株产量自交系配合力总效应为主要指标,结合其它性状配合力相对效应大小对9个自交系在玉米育种中的利用潜力进行了分析比较.结果表明:自交系昌7-2的利用潜力最高,其次为洛06、济533、郑22、豫8701、中72、868,而洛1544、郑58的利用潜力较低。     

14份新育玉米自交系应用潜力分析

以近年选育的14份玉米自交系为被测系, 采用NCⅡ交配设计方法, 研究10个性状的配合力, 并对自交系进行杂种优势类群划分。结果表明, 被测系各性状的一般配合力方差均达极显著水平, HX210和HX303作为亲本组配的杂种后代增产潜力较大, 可在育种中直接利用;HX458和HX3综合性状较差, 需改良后利用;HX303×K10等5个杂交组合具有较强的杂种优势, 有一定的增产潜力。依据单株产量的总配合力效应值将14份自交系划分出4个杂种优势群。     

不同性状对玉米种质优势类群划分结果的影响

利用常用玉米自交系为材料,按Griffing4模式进行双列杂交.以单株粒重和6个性状的总配合力值为依据,对20个自交系进行了聚类分析.结果表明,不同性状对聚类分析结果有一定的影响.     

蓖麻主要农艺性状的配合力分析

17个蓖麻亲本品种以NCⅡ交配设计配成3×14=42个杂交组合,F_1的配合力分析表明:雄亲13个性状的一般配合力差异均达显著或极显著水平,雌亲有10个性状达极显著水平。特殊配合力效应差异有12个性状达显著或极显著水平。产量性状的一般配合力以1716,山光大,永26和Lm型雌性系较高,且有其参与组合的特殊配合力效应也较高。一般配合力方差相对比率大的性状有:开花期、一级分枝数、单株粒重和百粒重。说明这些性状遗传上加性效应占主导地位。而株高、主穗性状、一级分枝蒴果数、一级分枝粒重、单株粒数的特殊配合力方差比率较大。表明其杂种优势以非加性效应占主导地位。     

12个玉米自交系的配合力分析

以12个玉米自交系为被测系,采用NCⅡ交配设计的原理和方法,研究了9个性状的配合力及其群体遗传参数。结果表明：被测系各性状的一般配合力方差均达极显著水平,98012、98008表现较优,可以进一步利用;98001、98005、98011综合性状较差,需要改良后利用;其余自交系部分性状的一般配合力较优,可用来改良其它自交系或作为选育二环系的基础材料。被测系多数性状的一般配合力方差大于特殊配合力方差,抽丝期、穗长、穗粗、穗行数、容重受遗传因素影响较大,可在早代对这些性状进行选择,而行粒数、百粒重、出籽率、单株产量受环境影响较大。     

优良玉米自交系丹T138配合力分析

以属于5个杂种优势群的24个常用玉米自交系为母本（P1）,优良玉米自交系T138-1及其秭妹系T138-2为父本（P2）,杂交获得了48个组合。分析了亲本自交系的一般配合力、杂交组合的特殊配合力和总配合力效应,主要结果表明：不同组合各性状配合力存在极显著差异。P1亲本,除出籽率GCA外,其他性状差异显著或极显著。P2亲本,生育期、株高、穗粗、行粒数、穗位、棒三叶面积GCA差异显著或极显著。P1与P2互作间的SCA方差除出籽率和小区产量差异未达显著水平外,其余10个性状的SCA差异均极显著。P1亲本各性状一般配合力差别很大,P2亲本T138-1出籽率一般配合力效应高于T138-2,其它性状GCA值均低于T138-2。穗位高、穗长、穗行数、行粒数、秃尖、百粒重、出籽率SCA值与其性状均值之间达到了正的极显著或显著相关,受环境影响较大。各性状总配合力效应与实际田间表现基本一致,生育期、株高、穗位高、棒三叶面积、穗长、穗粗、行粒数、百粒重总配合力效应与小区产量正相关。     

一个玉米F2：3群体主要性状的变异及相关分析

用自交系201与698-3杂交,创建了一个玉米F2:3群体,共233个家系.分析了该群体的穗长、秃尖长、穗粗、穗行数、行粒数、粒深、百粒重、出籽率和单株生产力等9个性状的变异及其相关性.结果表明.这些性状的变异度均很大,在不同家系间存在极显著的差异;除秃尖长外,频率分布均呈正态分布.各性状与单株生产力之间都存在极显著的相关关系,其中行粒数、百粒重、穗行数、粒深和出籽率对单株生产力的贡献最大.利用该群体中的变异性状,结合性状之间的相关性进行选择.可选育出新的高产玉米自交系.     

20份玉米种质选系的利用潜力分析

采用NCII遗传交配设计,以黑龙江省5份常用骨干自交系为测验种,与20份欧洲玉米种质选系配制100个组合,在黑龙江省3种不同生态环境下,分析20份欧洲玉米种质选系主要性状的配合力及杂种优势。结果表明,被测系之间的一般配合力效应差异达极显著,T04、T16-2、TF32和T218-4的产量及相关性状一般配合力表现优良,在玉米育种中具有较大的利用潜力;TF32×四-444在产量特殊配合力和杂种优势上均为最大值。与对照比较,杂种优势大于10%的组合大多为欧洲玉米种质选系×塘四平头类群自交系,说明欧洲玉米种质与塘四平头类群种质之间具有较强的杂种优势。     

5个玉米自交系配合力分析及应用评价

按P1×P2不完全双列杂交设计,用NCⅡ分析方法,对引入的5个法国玉米自交系的9个性状的配合力及其群体遗传参数进行研究.结果表明:引3和引4一般配合力高,其综合性状较好;在育种工作中对玉米的生育期等性状宜早代选择,而对单株粒重等性状应进行晚代选择.     

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.     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

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.