玉米雄性不育突变体ms1153的遗传分析与基因定位

以玉米雄性不育突变体ms1153为材料,通过减数分裂期花粉母细胞染色体观察和不同发育时期花药石蜡切片分析突变体不育表型产生的原因,利用F₁和F₂群体确定突变体MS1153的遗传方式和基因ms1153物理位置。结果表明,与野生型相比,突变体植株在营养生长期无明显差异,在生殖生长阶段花药不能从颖壳外露,成熟花粉粒内无淀粉积累。细胞学分析发现,突变体减数分裂过程正常,但减数分裂后绒毡层降解推迟。遗传分析表明,突变体ms1153的不育性状受1对隐性核基因控制。利用图位克隆的策略将MS1153基因定位于玉米第4染色体分子标记8243与8275之间,物理区间为221.4~226.2 Mb,此区间内没有已克隆雄性育性基因,说明MS1153是一个新的玉米雄性育性基因。     

玉米禾谷镰孢穗腐病抗性的QTL定位

以3个高抗玉米自交系承351、丹598、吉V203和1个高感自交系ZW18为亲本,分别构建3个F₂群体及其对应的F_2:3家系,通过对F_2:3家系发病果穗进行图像处理的方法鉴定抗病表型,对禾谷镰孢穗腐病抗性进行QTL定位。3个F₂群体共检测到11个与禾谷镰孢穗腐病抗性有关的QTLs,分别可解释4.87%～40.98%的表型变异率。来源于抗病亲本承351的QTL-qRgr7-1位于7.02 bin,可解释高达13.76%～40.98%的表型变异率。通过与前期病害评级方法定位到的QTLs相比,qRgr7-1在Bins7.02上和qRger7.1完全重合,qRgr2-1在Bins2.01-2.02上和qRger2.1完全重合,qRgr10-1在Bins10.01-10.02上和qRger10.1完全重合。基于图像分析定位到的qRgr9-1、qRgr1-2、qRgr3-1分别与基于抗病评级定位到的区间存在重叠区域。利用不同方法定位到了相同的QTLs,一方面说明基于图像分析进行表型鉴定有一定的准确性,另一方面也验证了这些QTLs位点的真实性。     

野生二粒小麦抗条锈病基因 YrH52的RGA分子标记

为开发与野生二粒小麦抗条锈病基因YrH52紧密连锁的分子标记,并为该基因的克隆及应用奠定基础,运用RGA (Resistance gene analog) 分子标记法,以 YrH52定位作图F₂群体形成的F₄抗性和感病基因池（Gene pool）及其亲本（抗病材料H52与感病材料Ldn）进行多态性筛选分析,共获得17个RGA分子标记。使用已有的遗传图并进行MultiPoint分析,构建了由与抗性（H）和感病(L) 两个亲本对应的显性位点组成的两个遗传图,即H遗传图和L遗传图。在H图中, YrH52与10个RGA标记,即 X_uhw3, X_uhw17, X_uhw18, X_uhw23, X_uhw36, X_uhw38, X_uhw46, X_uhw59, X_uhw62 和 X_uhw73 紧密连锁, 其中 X_uhw23 标记为共显性分子标记,连锁距离为1.0 cM。在L图中,发现 X_uhw57, X_uhw68, X_uhw189, X_uhw192及其 X_uhw23与 YrH52 相聚成簇（Cluster）。本研究结果说明RGA分子标记结合集群分离分析法 （Bulked segregant analysis,BSA）是一种快速开发与小麦抗病基因紧密连锁标记的有效方法,对小麦抗条锈病分子育种和抗病基因的克隆具有促进作用。     

水稻抗稻瘟病突变体lmm326的鉴定与调控通路初步分析

【目的】绝大多数水稻类病斑突变体中免疫系统被激活可以有效提升其对稻瘟病的抗性,为进一步解析类病斑突变体抗病的分子机制,对类病斑突变体lmm326进行了研究。【方法】lmm326是粳稻中花11通过EMS辐射诱变,经多代自交和回交获得的一个类病斑突变体,并将突变体分别与中花11和Dular杂交获得的F_2群体用于遗传分析,采用图位克隆的方法对目的基因进行精细定位。【结果】5叶期时,该突变体下部叶片表面开始出现类病斑表型;与野生型相比,突变体叶片光合色素含量、净光合速率、株高、结实率、单株有效分蘖数、千粒重等显著下降;突变体带病斑叶片中死亡细胞数量及过氧化氢的积累量明显多于野生型;突变体相较于野生型对4个已鉴定的稻瘟病生理小种的抗性明显提高。遗传分析表明该性状由一对单隐性核基因控制。采用图位克隆方法将该基因定位在第1染色体长臂端38kb的区间内,其中包含6个开放阅读框。测序发现基因Os01g0919900第2外显子上对应CDS的第433位碱基由C突变成T,最终导致其编码蛋白的第145个氨基酸由苯丙氨酸(F)变为亮氨酸(L)。qRT-PCR结果显示,与野生型相比,lmm326中参与水杨酸信号通路的防卫基因显著上调表达。【结论】LMM326与OsSSI2互为等位基因,该基因可能参与负调控水杨酸信号转导途径,其突变激活了水稻体内的防卫反应。     

Ae显性突变体对玉米农艺性状及直链淀粉含量的影响分析

玉米直链淀粉是重要的食品和工业原料,高直链淀粉性状的产生受多种酶和基因-环境等因素的共同影响。玉米ae基因（amylose extender）突变导致子粒中直链淀粉含量增高、子粒表面皱缩、淀粉颗粒呈不规则形状、尺寸不均匀且表面基质蛋白增多,用于玉米育种后获得的品种直链淀粉含量升高,产量显著降低。通过将显性Ae突变体与16份优质玉米自交系杂交,对F₁代植株进行开花期、株型、产量性状调查,分析F₁代子粒总淀粉、直链淀粉的含量。结果表明,Ae突变体与不同的自交系杂交,F₁代直链淀粉含量及产量的变化存在明显差异,与基因型有密切关系,以Ae突变体和W16F41、CA240为亲本杂交,可显著提高直链淀粉含量同时产量变化最小。根据F₁代表现筛选直链淀粉含量提高、产量变化较小的双亲配制杂交种,可加速高直链淀粉玉米新品种培育进程。     

EMS诱变玉米自交系种质创新应用

利用0.5 mg/L EMS诱变玉米自交系K22及B73花粉，构建2 206个株系不同遗传背景的玉米突变体库，从M₂和M₃后代筛选到包括株型、叶型、叶色、育性、抗逆、表皮形态建成等表型变异的一系列突变体。具有育种应用潜能的E16、E199和W594突变材料，可供用于选育矮秆、低穗位高、耐密植抗倒伏型新品种。对调控植物表皮形态建成的E88和sep-1（smooth epidermal pavement cell lobes-1）突变体进行表皮形态、发育模式鉴定及遗传学分析，构建了F_2：3分离群体。     

利用分子标记定位玉米小粒突变体mn7基因的研究

利用甲基磺酸乙酯(EMS)对玉米自交系郑 58进行诱变，获得 1个可以稳定遗传的小粒突变体mn7(miniature 7)。mn7成熟子粒表现为体积变小、子粒偏白、胚乳发育缓慢，百粒重降低 60.2%，粒长、粒宽、粒厚均极显著降低。mn7突变体的子粒在授粉后 15 d即可观察到明显小于野生型的子粒。对其自交后代和回交后代的遗传分析表明，该性状受隐性单基因控制。用mn7纯合体与自选玉米自交系 19HL3012杂交构建的包含 348个个体的 F₂分离群体，将该基因定位于玉米第 7染色体上 bin7.02区域内分子标记 umc2327和 SYM232之间 5.8 cM的范围内，距umc2327为 4.4 cM，距 SYM232为 1.4 cM。初步的生物信息学分析表明， mn7可能是 1个新基因或新等位基因。     

玉米碳水化合物分配缺陷突变体ygl3的光合特性及遗传分析

以快中子辐射诱变玉米自交系PH6WC筛选得到的碳水化合物分配缺陷突变体ygl3为材料,通过叶片内叶绿素含量和碳水化合物含量的测定、叶绿体结构显微观察、光合特性和遗传特性等进行分析。结果表明,与野生型相比,突变体叶绿体数目变少,形态松散,维管束鞘叶绿体积累了大量的淀粉,淀粉颗粒排列不规则且体积增大,导致了叶绿体的膨胀和膜结构的破坏;叶片中淀粉、葡萄糖、果糖的含量都显著高于野生型,表现出玉米碳水化合物分配缺陷的典型表型特征;突变体的叶绿素a、叶绿素b及总叶绿素含量都显著低于野生型;净光合速率(Photo)、气孔导度(Cond)、蒸腾速率(Trmmol)均极显著低于野生型,胞间二氧化碳浓度(Ci)高于野生型。遗传分析表明,(ygl3×Mo17) F₂分离群体突变型(黄化)与野生型(绿色)植株性状分离符合1∶3分离比例,表明该突变体受单个核隐性基因控制。     

玉米Opaque-2基因在毕赤酵母中的表达

从玉米自交系辽2345授粉后18 d的胚乳中提取总RNA,经反转录后得到第一链cDNA,利用Opaque-2基因的特异引物克隆出该基因的全编码区,将该编码区的全序列以正确的阅读框架利用Infusion同源重组的方法亚克隆到毕赤酵母表达载体pPIC9的α因子下游,并置于AOXⅠ启动子控制下,利用pPIC9表达载体上的特异引物进行PCR鉴定,鉴定后的重组质粒用Bgl Ⅱ酶切线性化后,电转化导入甲醇型毕赤酵母菌株GS₁15中,利用MM、MD和菌落PCR的方法筛选出Mut⁺表型,得到的重组子以甲醇诱导表达蛋白。经SDS-PAGE结果显示,Opaque-2蛋白得到表达,其相对分子质量（Mr）约为47 KD。     

利用CRISPR-Cas9技术编辑ZmSh2基因创制超甜玉米新种质

选取玉米ZmSh2基因,利用CRISPR-Cas9技术构建基因编辑载体pBUE411-ZmSh2,以玉米C01未成熟的幼胚组织为受体,利用农杆菌介导法将目的基因转入到玉米幼胚中,以草铵膦为选择剂进行筛选获得ZmSh2基因编辑的突变体株系。通过表型观察发现,编辑的纯合突变体材料明显比对照玉米自交系C01褶皱,使用手持式糖度仪检测突变体植株的甜度可达到25%。结果表明,利用CRISPR-Cas9技术能够创制出超甜玉米新种质材料,为CRISPR-Cas9介导玉米其他性状定向遗传改良提供了重要的理论和实践依据。     

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.