Modelling the population size and dynamics of the British grey seal

相似文献   

梨抗黑星病的遗传育种研究

鸭梨、早酥等8个品种15个杂交组合的F1群体对黑星病的抗性表现为质量性状的遗传。抗病性对感病性为显性。80％以上的供试组合F1对黑星病的抗感分离比可用4对基因控制的抗病性来解释。亲本品种的抗性对杂交后代的影响较大,且品种间有差异。佳白梨、五九香梨是梨抗黑星病育种的良好亲本。西洋梨及其杂种在梨抗黑星病育种中作一亲或双亲是有利的。     

苹果潜隐病毒的研究——Ⅰ 苹果感染茎沟槽病毒后过氧化物酶的活性及其同工酶的变化

对金冠、富士幼树接种茎沟槽病毒(SGV),分期测定其叶片的过氧化物酶活性及过氧化物酶同工酶,结果表明:苹果植物接种SGV后过氧化物酶活性增高,增酶高峰出现于接种后20—35天;过氧化物酶同工酶也发生变化,在接种后20—30天,富士、金冠两个品种先后各出现了两条健株所没有的G、I带和I、K带。     

Metagenomic discovery of biomass-degrading genes and genomes from cow rumen

The paucity of enzymes that efficiently deconstruct plant polysaccharides represents a major bottleneck for industrial-scale conversion of cellulosic biomass into biofuels. Cow rumen microbes specialize in degradation of cellulosic plant material, but most members of this complex community resist cultivation. To characterize biomass-degrading genes and genomes, we sequenced and analyzed 268 gigabases of metagenomic DNA from microbes adherent to plant fiber incubated in cow rumen. From these data, we identified 27,755 putative carbohydrate-active genes and expressed 90 candidate proteins, of which 57% were enzymatically active against cellulosic substrates. We also assembled 15 uncultured microbial genomes, which were validated by complementary methods including single-cell genome sequencing. These data sets provide a substantially expanded catalog of genes and genomes participating in the deconstruction of cellulosic biomass.     

苹果霉心病Alternaria spp在芽中越冬的研究

用红星(starking delicious)、金冠(Golden delicious)、秦冠(Qin delicious)三个品种的短果枝顶芽(花芽)、中长枝顶芽及中长枝侧芽(叶芽)等三种芽的鳞片分层剥取后,采用组织分离法和洗涤离心法分析研究,发现这三个品种芽的鳞片均带有AIternaria spp。三个品种中红星的带菌率及所带孢子量最高,三种芽中短果枝顶芽的带菌率及带孢子量最高,同时鳞片上所带的孢子于次年春均能荫发,可作为初次侵染源。三个品种中,红星田间果实发病率最高,这与芽内带A.spp及其孢子量成正相关。以上结果表明了A.spp能以菌丝和分生孢子在芽中越冬,所以芽是霉心病的一个重要越冬场所。     

PI3Kgamma is a key regulator of inflammatory responses and cardiovascular homeostasis

Class I phosphoinositide 3-kinase (PI3K) signaling pathways regulate several important cellular functions, including cellular growth, division, survival, and movement. Class IB PI3K (also known as PI3Kgamma) links heterotrimeric GTP-binding protein-coupled receptors to these pathways. Activation of class IB PI3K results in the rapid synthesis of phosphatidylinositol-3,4,5-trisphosphate [PtdIns(3,4,5)P3] and its dephosphorylation product PtdIns(3,4)P2 in the plasma membrane. These two lipid messengers bind to pleckstrin homology domain-containing effectors that regulate a complex signaling web downstream of receptor activation. Characteristic features of this pathway are the regulation of protein kinases and the regulation of small guanosine triphosphatases that control cellular movement, adhesion, contraction, and secretion. Most of the ligands that activate class IB PI3K are involved in coordinating the body's response to injury and infection, and recent studies suggest that small molecule inhibitors of this enzyme may represent a novel class of anti-inflammatory therapeutic agents.     

Genetic variability and relationships in nine South African cattle breeds using microsatellite markers

Tropical Animal Health and Production - Genetic variability within and between breeds allows adaptation to a changing environment and consequently prepares producers for the future. Eleven...     

Hsp90 gene, an additional target for discrimination between the potato cyst nematodes, Globodera rostochiensis and G. pallida, and the related species, G. tabacum tabacum

The heat-shock gene, Hsp90, was targeted as a new variable genomic region to supplement other DNA-based tests for identification and discrimination of Globodera pallida, G. rostochiensis and G. tabacum tabacum. Populations of the potato cyst nematodes, G. pallida and G. rostochiensis (PCN), originating from Canada, France, Belgium and USA, together with two populations of G. tabacum tabacum from the USA and France were used for the amplification of a fragment of the Hsp90 gene. General and specific primers and probes for each species were derived from the consensus and non-consensus regions of the aligned sequences, respectively. A triplex conventional PCR assay, using a general forward and reverse or three specific reverse primers, as well as a real-time PCR using general primers and specific TaqMan probes, were developed. Melting curve analysis and restriction fragment polymorphisms using high resolution electrophoresis were explored for identifying PCR amplicons that characterized and discriminated the three Globodera species in both pure and mixed samples. Results from the different molecular assay strategies confirmed the usefulness of Hsp90 as a new additional gene target and showed that several different test options could be used for discrimination of PCN.     

施钾对油菜分枝生产力及籽粒品质的影响

在有效钾水平较低的砂质壤土上进行不同钾肥用量及施用方法试验,并测定了油菜植株不同节位分枝的籽粒产量、产量构成因素及籽粒品质。结果表明：①施钾可显著提高油菜籽粒产量,并改变籽粒产量在主花序及分枝间的分配比例;②油菜不同节位分枝生产力对钾肥的反应不同,钾肥主要提高中、下位分枝的生产力,并缩小分枝间生产力的差距,而对主序及上位分枝的生产力作用较小甚至有一定程度的消弱作用;③施钾数主要提高了分枝的角果数,对千粒重作用较小,对每角粒数有一定的负效应;④施钾可明显提高籽粒含油率,对脂肪酸组成影响很小,但有提高芥酸含量的趋势;⑤分期施钾提高分枝生产力的效果优于一次性基施。     

柑桔上胶孢炭疽菌生理分他的研究——Ⅲ、培养及生长特性的测定

对中国柑桔上分离到的25个柑桔胶孢炭疽菌分离系,进行培养及生长特性测定。结果表明,25个分离系在培养及生长特性上存在着差异,但这种差异不能说明柑桔上的胶孢炭疽菌存在着生理分化,同时也与该菌致病性差异不相关。