利用SRAP标记研究繁殖群体量对芝麻种质资源遗传完整性的影响

研究繁殖群体量对芝麻种质资源遗传完整性的影响,以确定适宜的繁殖群体量,为种质资源更新繁殖提供理论参考。利用SRAP分子标记技术对育成品种和地方种质2种不同类型的芝麻种质资源的不同群体量的遗传参数进行分析。结果显示：（1）育成品种：随机抽取了10、15、20、25、30、35和40株的7个群体量梯度,24对引物共扩增到DNA位点525个,平均每对引物扩增21.88个,多态性位点24个,占总位点数的4.57%。随着群体量的不断增加,扩增总位点数和遗传相似系数均表现为不断增加,多态性位点比率和遗传距离均呈现先升后降趋势。当群体量达到35~40株时,遗传相似系数达到一定高值（0.998 73和1.000 00）,遗传距离降低到一定程度（0.000 64和0.000 00）。聚类结果显示群体量为35和40株的群体被紧密聚在一起,因此可认为育成品种的繁殖群体量达到35~40株时可以保持其遗传完整性;（2）地方种质：随机抽取10、15、20、25、30、35、40、45、50、55和60株的11个群体量梯度,24对引物共扩增到DNA位点552个,平均每对引物扩增23.00个,多态性位点44个,占总位点数的7.97%。随着群体量的不断增加,扩增总位点数波动上升,多态性位点比率和遗传距离呈先升后降然后再轻度变化的趋势。遗传相似系数则随群体量的增大表现为先下降后上升然后轻度下降后再次回升的趋势,并于群体量为40和60株时达到最大值0.99758。聚类结果显示群体量为50、55和60株的群体被紧密聚在一起,因此可认为地方种质的繁殖群体量达到50~55株时可保持其遗传完整性;（3）在芝麻种质资源繁育中,不同类型的种质资源由于其遗传背景的纯度存在差异,应选择不同的繁殖群体量以保持其遗传完整性。     

茶树新品种“湘波绿2号”父本的SSR标记鉴定

为在分子水平上鉴定"湘波绿2号"的父本,本研究采用SSR标记对其母本和5个可能父本进行了分析。结果表明,筛选的29对引物共检测到83个等位位点,每个引物1~4个,平均2.86个。湘波绿2号与福鼎大白茶及5个可能父本的相同位点数分别占其扩增总位点数的71.93%、64.91%、94.74%、66.67%、52.63%和70.18%,最多的为湘波绿,最少的为云大72-04。7份供试材料间相似系数变幅为0.45~0.80,平均0.55,其中湘波绿2号与湘波绿的相似系数最大(0.80)。根据相似系数UPGMA聚类,在相似系数0.55处将参试7份材料分为5类。参试材料的相似系数和亲缘关系树状图在分子水平上显示了湘波绿与湘波绿2号的亲缘关系最近,可能为湘波绿2号的父本。     

茶树新品系“53-34”父本的EST-SSR标记鉴定

本研究采用EST-SSR标记对茶树新品系＂53-34＂及其母本和4个可能父本进行了分析。结果表明：24对引物共检测到69个等位位点,平均2.88;53-34与湘波绿及4个可能父本的相同位点数分别占其扩增总位点数的85.71%、71.43%、65.71%、60.00%、74.26%,最大为湘波绿,最小为福云7号。6份供试材料间相似系数变幅为0.44~0.77,平均0.57。根据相似系数矩阵按UPGMA法进行聚类,在相似系数平均值0.57处可将参试的6份材料划分为三大类：第Ⅰ类高芽齐;第Ⅱ类湘波绿、53-34与古蔺牛皮茶;第Ⅲ类云大72-04与福云7号。参试材料的相似系数和亲缘关系树状图在分子水平上显示了53-34的4个可能父本中,古蔺牛皮茶与其亲缘关系最近,可能为53-34的父本。     

89份油菜区试品种的AFLP指纹图谱分析

以2004-2005年度全国冬油菜区试的89份参试品种为材料，运用筛选确定的4对AFLP核心引物对这些品种进行分子标记分析，共获得67个多态性片段，其中多态性位点占总扩增位点的27.80％，利用67个多态性片段初步构建了这些品种的AFLP指纹图谱。聚类结果显示，在相似系数为1.00时，89份区试品种完全区分开；同一单位育成的品种的遗传距离较近。对不同类型品种（品系）遗传多样性指数分析, 结果显示，三系杂种的遗传多样性程度最高，常规种居中，两系杂交种最低。     

SSR标记马铃薯育成品种的遗传多样性分析

分析65份马铃薯(Solanum tuberosum L.)育成品种的遗传关系,为主食化马铃薯新品种选育中亲本的选配提供理论依据。采用轮筛法从100对马铃薯SSR引物中筛选出条带清晰、重复性好、多态性较高的引物。利用筛选出的25对SSR引物对65份马铃薯品种的遗传多样性进行扩增分析,用NTSYS-pc 2.1软件分析供试材料的遗传关系。25对SSR引物共扩增出145个位点,其中多态性位点145个,占总扩增位点的100%。供试材料间的遗传相似系数为0.60～0.93,表明供试材料间遗传差异相对较大。UPGMA聚类结果表明,在遗传相似系数为0.60时,供试材料被分为两大类,‘华恩1号’单独聚为第一类,其余64份材料聚为第二类;在遗传相似系数为0.61时,第二类又分为两个亚类,‘农天1号’、‘甘谷紫’、‘天薯9号’、‘五龙洋芋’、‘天薯10号’聚为第一亚类;其余59份材料聚为第二亚类;在相似系数为0.64时,第二亚类又分为2个亚亚类:第1亚亚类为‘天薯11号’、‘青薯10号’、‘青薯6号’、‘甘谷红’和‘秦州红’,其余54份材料聚为第2亚亚类。结果表明,供试材料中部分品种间亲缘关系较远,但同一育种单位育成的品种遗传差异较小,育种中可以充分利用遗传关系较远的马铃薯品种作为亲本材料。     

四川小麦品种的遗传多样性及其对条锈病和白粉病的抗性

小麦条锈病和白粉病是四川小麦生产中的两大主要病害。为系统掌握四川小麦品种的遗传差异性及抗病性水平,以大田样品和近10年审定品种为试验材料,利用SSR分子标记对其进行遗传多样性分析,并对其成株期条锈病和白粉病抗性进行了鉴定。结果显示,115份大田样品和33个审定品种构成的总群体共扩增出38条多态性带,遗传相似系数变化范围为0.62~1。大田样品的观察等位基因数、有效等位基因数、基因多样性指数、信息指数、多态性位点数和多态位点百分率分别为1.868 4、1.422 8、0.253 0、0.386 7、33和86.8%,各项参数值均高于审定品种。聚类结果显示,多数审定品种与大田样品同源且出现于多个采样地点。抗性监测结果表明,四川省生产上大面积种植的小麦品种抗条锈性丧失明显,对白粉病的抗性丧失不明显。     

中国部分优质小麦品种(系)遗传多样性的SSR分析

为明确中国优质小麦品种(系)间的遗传关系,利用21对SSR引物对75份优质小麦品种(系)进行了遗传多样性分析.结果表明,21对引物共检测到135个等位位点,每对引物等位位点数在2～13之间,平均为6.4个.位点多态性信息含量(PIC)变幅为0.49～0.90,平均为0.76.品种间遗传相似系数(GS)变幅为0.46～0.96,平均为0.66.SSR标记能将75份优质小麦品种(系)分成五大类.聚类分析结果与品种系谱来源及地域比较吻合.     

小麦穗部组织 EST-SSR标记引物开发及其在小麦遗传多样性分析中的应用

为了筛选光温敏雄性不育系（PTGMS）小麦穗部的EST-SSR 分子标记,探讨其EST-SSR标记用于小麦品种遗传差异研究的可行性,用SSRSCAN软件对PTGMS小麦穗部的3 264条EST序列进行SSR 位点查找,结果得到108条含有SSR标记的序列。设计64对引物并进行PCR扩增及非变性聚丙烯酰胺凝胶(PAGE)电泳。结果显示,64对引物中有41对能在42个小麦品种中扩出PCR条带,有多态性条带的为36对,具有较高的扩增效率。聚类分析结果显示,42个小麦品种的遗传相似系数在0.64~0.87之间,3个PTGMS小麦品种具有较高的遗传相似系数。     

姬松茸种质资源多样性SRAP分析

对从国内收集的16个姬松茸菌株的基因组DNA进行SRAP分析,4对引物共获得31条明显的多态性扩增条带,其中多态性位点数为30,多态性位点百分比为96.77％;平均等位基因位点数为1.967 7,平均有效等位基因位点数为1.408 6,物种水平上Nei's基因多样度指数为0.246 8,Shannon遗传多样性指数为0.384 0。采用UPGMA方法进行聚类分析,结果显示不同姬松茸菌株间的遗传背景呈现一定的差异性,产地差异性大,种内差异性小;在相似系数约为0.7的水平上,16个菌株可以分为4大类。SRAP分子标记适合姬松茸的DNA遗传多样性分析,可以作为姬松茸菌种鉴定的依据之一。     

小麦育种亲本材料遗传多样性的SSR分析

为了明确目前中国小麦育种亲本材料间的遗传关系,为育种工作提供有益信息,利用74对SSR引物对103份小麦主要亲本材料进行了遗传多样性分析,共检测出298个等位位点,每对引物等位位点数在2～14之间,平均为4.03个.位点多态信息含量(PIC)变幅为0.020～0.899,平均为0.429.品种(系)间遗传相似系数(GS)变幅为0.369～0.948,平均值为0.636.74对SSR标记能将103份小麦品种(系)分为五大类.聚类分析结果与品种系谱来源及地域比较吻合.     

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.     

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.