A diverse metaphyte assemblage from the Neoproterozoic black shales of South China

A fossil assemblage of diverse megascopic benthic algae is well preserved on bedding planes in black siliceous shales of the Neoproterozoic Lantian Formation (upper Sinian) at Lantian village, Xiunng county, Anhui Province, South China. Based on morphological differences, 12 taxa are recognized. Most specimens show both a holdfast and a vegetative thallus, some with dichotomous branching, which reveals that they are multicellular benthic algae. Each type presents a certain morphological appearance, e.g., spheroidal - Chuaria sp., filamentous - Doushantuophyton rigidulum , fan-like - Flabellophyton lantianensis. Four to six different benthic forms and more than 15 individuals are well preserved on the same bed with an area less than 150 cm². These confirm that a great morphological evolutionary radiation of seaweeds took place no later than the Lantian epoch, with an absolute age around 570 Ma. Growth cycles in Flabellophyton strigata n.sp. reveal that periodical events, such as seasonal variations, occurred in that epoch. A benthic assemblage consisting of three differentiated macroscopic remains is similar to the Miaohe Biota reported from the Doushantuo Formation of the Yangtze Gorges 1200 km away, allowing biostratigraphic correlation of both of these Neoproterozoic Formations.     

Quantitative trait loci for rice yield-related traits using recombinant inbred lines derived from two diverse cultivars

The thousand-grain weight and spikelets per panicle directly contribute to rice yield. Heading date and plant height also greatly influence the yield. Dissection of genetic bases of yield-related traits would provide tools for yield improvement. In this study, quantitative trait loci (QTL) mapping for spikelets per panicle, thousand-grain weight, heading date and plant height was performed using recombinant inbred lines derived from a cross between two diverse cultivars, Nanyangzhan and Chuan7. In total, 20 QTLs were identified for four traits. They were located to 11 chromosomes except on chromosome 4. Seven and five QTLs were detected for thousand-grain weight and spikelets per panicle, respectively. Four QTLs were identified for both heading date and plant height. About half the QTLs were commonly detected in both years, 2006 and 2007. Six QTLs are being reported for the first time. Two QTL clusters were identified in regions flanked by RM22065 and RM5720 on chromosome 7 and by RM502 and RM264 on chromosome 8, respectively. The parent, Nanyangzhan with heavy thousand-grain weight, carried alleles with increased effects on all seven thousand-grain weight QTL, which explained why there was no transgressive segregation for thousand-grain weight in the population. In contrast, Chuan7 with more spikelets per panicle carried positive alleles at all five spikelets per panicle QTL except qspp5. Further work on distinction between pleiotropic QTL and linked QTL is needed in two yield-related QTL clusters.     

羟基脲(Hydroxyurea)对细胞周期与珠蛋白基因表达的影响(简报)

已有许多证据表明羟基脲能增加镰状细胞贫血及β-地贫病人的胎儿型血红蛋白(HbF)的合成。最近,有人报道羟基脲也能使一些患有β-地贫病人的β-珠蛋白基因表达增加。K562细胞是人红白血病细胞株,它只能表达胚胎型(ε-)与胎儿型(γ-)珠蛋白基因,而不能表达成年型(β-)珠蛋白基因。因此,K562     

Merging Maddenia with the morphologically diverse Prunus (Rosaceae)

Maddenia (Rosaceae) has been distinguished from Prunus on the basis of its tepaloid perianth and one‐ to two‐carpellate gynoecium. These distinctive morphological traits nonetheless overlap with several Prunus spp. Maddenia has previously been shown to be nested within Prunus, more specifically within a clade containing members of subgenera Laurocerasus and Padus, but its phylogenetic position within that clade has not been defined precisely. This study clarifies the position of Maddenia within Prunus through phylogenetic analyses of nuclear ribosomal internal transcribed spacer (ITS) and plastid ndhF sequences, with an expanded sampling of tropical species of subgenus Laurocerasus and the inclusion of three Maddenia spp. The monophyly of Maddenia is supported by both the ITS and ndhF analyses, but both datasets support the inclusion of Maddenia in Prunus. All trees from the ITS analysis and some trees from the ndhF analysis also support a close alliance of Maddenia with a clade comprising temperate species of subgenera Laurocerasus and Padus. On the basis of these results, all recognized species of Maddenia are herein formally transferred to Prunus, which requires four new combinations and one new name: Prunus fujianensis (Y.T.Chang) J.Wen, comb. nov. ; Prunus himalayana J.Wen, nom. nov. ; Prunus hypoleuca (Koehne) J.Wen, comb. nov. ; Prunus hypoxantha (Koehne) J.Wen, comb. nov. ; and Prunus incisoserrata (T.T.Yü & T.C.Ku) J.Wen, comb. nov. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 236–245.     

中国元三甲螨属六新纪录种(甲螨亚目,元三甲螨科)

记述中国元三甲螨属6新纪录种:双元三甲螨Oribotritia anceps NiedbaΙa,2000、狭元三甲螨Oribotritia angusta Mahunka,1982、亚洲元三甲螨Oribotritia asiatica Hammer,1977、父岛元三甲螨Oribotritia chichijimensis Aoki,1980、大元三甲螨Oribotritia gigas Bayoumiet Mahunka,1979、尼泊尔元三甲螨Oribotritia nepalensis NiedbaΙa,2000,并给出了6新纪录种的特征图。研究标本除注明保存在波兰亚当密茨凯维奇大学动物分类与生态学系(DATE)外,其余均保存在中国科学院动物研究所国家动物博物馆。     

小兴安岭4种原始红松林群落类型生长季土壤呼吸特征

为阐明小兴安岭地带性植被原始红松林土壤呼吸各组分的碳排放速率及其对土壤水热变化的响应规律,采用挖壕法和红外气体分析法测定土壤表面CO2通量(Rs),确定4种原始红松林群落类型生长季的土壤总呼吸(Rt)中土壤微生物呼吸(Rh),根系呼吸(Rr)和凋落物呼吸(Rl)的贡献量动态变化及其影响因子。结果表明:生长季内,4种原始红松林群落类型的Rt、Rh、Rr具有明显的季节性变化,7-9月份较高,6月份和10月份较低。Rh对Rt的贡献量最高,平均在58.8%;Rr对Rt的贡献量次之,平均为26.5%;Rl对Rt的贡献量相对较小,平均为12.5%。生长季土壤呼吸速率与5cm深土壤温度相关性极显著(P0.01)。Rr和Rh的Q10值分别为2.88和2.23。表明根呼吸对土壤温度的敏感性高于微生物呼吸。生长季平均土壤呼吸速率的依次为:椴树红松林(6.38μmol·m-·2s-1)云冷杉红松林(6.32μmol·m-·2s-1)枫桦红松林(5.95μmol·m-·2s-1)蒙古栎红松林(2.86μmol·m-·2s-1)。4种原始叶红松林群落类型间的Rh和Rr也存在一定差异。     

自发性高血压大鼠中枢血管紧张素Ⅱ的变化对中枢肾上腺素和去甲肾上腺素含量的影响

自发性高血压大鼠中枢肾上腺能递质含量异常,然其原因仍不清楚。本工作发现:12周龄易卒中型自发性高血压大鼠(SHRSP)脑桥,下丘脑后部、尾核中去甲肾上腺素(NE)含量及延髓、下丘脑前部,下丘脑后部中肾上腺素(E)含量均高于同龄 Wista Kyoto 大鼠(WKY),SHRSP 中枢 AⅡ含量亦明显高于同龄 WKY;向8周龄 SHRSP 和 WKY 侧脑室慢性灌注巯甲丙脯氨酸,不仅降低动脉血压及各脑区AⅡ含量,亦使中枢 NE 及 E 水平下降,但巯甲丙脯氨酸对 SHRSP 的影响远较对 WKY 明显。结果提示:SHRSP 中枢肾上腺能递质含量增加可能与 SHRSP 中枢 AⅡ量含量升高以及 SHRSP 中枢 AⅡ对中枢肾上腺能递质的促释放调节机制明显易化有关。     

Assessment of genetic and pheromonal diversity of the Cydia strobilella species complex (Lepidoptera: Tortricidae)

Combining pheromone trapping and genetic analyses can be useful when trying to resolve complexes of closely related insect taxa that are difficult to distinguish based on morphological characters. Nearctic and Palearctic populations of the spruce seed moth, Cydia strobilella L., have been considered taxonomically synonymous since 1983, but more recent work revealing distinct sex pheromones for Canadian and Swedish moths suggest that populations in the two regions belong to different species. In order to test this hypothesis, we performed field trapping using different pheromone lures at ten sites in North America, Europe and Asia, and reconstructed phylogenetic relationships among trapped moths using mitochondrial (cytochrome oxidase subunit I) and nuclear (elongation factor 1 alpha) DNA sequence data. Trapping data and tree topologies for both genes revealed distinct pherotypes in North America and Eurasia. A genetically distinct population from China was investigated further with respect to its sex pheromone. Electrophysiological data indicated that Chinese females produce a deviant ratio of the sex pheromone components (dienic acetates) compared to Swedish females. However, trapping experiments in both areas revealed a similar broad response profile in males to a wide range of acetate ratios, and these populations should be considered taxonomically synonymous. A previous suggestion of an agonistic effect on the attraction of C. strobilella males in Sweden when adding the corresponding alcohols to the binary acetate blend was also tested in Sweden as well as in China, with no observed effect on attraction of males. In conclusion, our study demonstrates the great potential of using pheromone trapping as a tool for identification and delimitation of taxa within cryptic species complexes. Based on our data, Nearctic and Palearctic populations of C. strobilella should be considered different species, and C. youngana Kearfott stat. rev. is resurrected here as valid name for North American populations, which was the case before the revision in 1983.     

3种落叶松幼苗对CO2升高的光合生理响应

采用Li-6400便携式光合作用测定系统研究CO2升高对长白落叶松(Larix olgensisHerry.),日本落叶松(Larix kaempferiCarr.)和兴安落叶松(LarixgmeliniRupr.)当年生和1年生幼苗的光合特性的影响。结果表明:CO2升高使3种落叶松光饱和光合速率(Pmax)和呼吸速率均有不同程度的增加,其中,长白落叶松当年生和1年生幼苗Pmax分别比对照提高了91%和83%,日本落叶松当年生和1年生幼苗Pmax分别比对照提高了71%和94%,而兴安落叶松当年生和1年生幼苗Pmax分别比对照提高了32%和106%。除兴安落叶松外,CO2升高使所有落叶松当年生幼苗的光补偿点(LCP)下降,说明当年生幼苗对CO2浓度升高的反应更敏感。CO2升高使日本落叶松当年生和1年生幼苗光饱和点(LSP)都升高,反映了其光合作用提高的潜力较大。CO2升高条件下,除1年生兴安落叶松外,其他处理的落叶松最大量子效率(AQYmax)均增加。比较分析表明,在未来大气CO2浓度升高条件下,日本落叶松的生长潜能可能最大,具有较强的生态优势,长白落叶松次之,兴安落叶松最小。     

Conditional QTL mapping of protein content in wheat with respect to grain yield and its components

Grain protein content in wheat (Triticum aestivum L.) is generally considered a highly heritable character that is negatively correlated with grain yield and yield-related traits. Quantitative trait loci (QTL) for protein content was mapped using data on protein content and protein content conditioned on the putatively interrelated traits to evaluate possible genetic interrelationships between protein content and yield, as well as yield-related traits. Phenotypic data were evaluated in a recombinant inbred line population with 302 lines derived from a cross between the Chinese cultivar Weimai 8 and Luohan 2. Inclusive composite interval mapping using IciMapping 3.0 was employed for mapping unconditional and conditional QTL with additives. A strong genetic relationship was found between protein content and grain yield, and yield-related traits. Unconditional QTL mapping analysis detected seven additive QTL for protein content, with additive effects ranging in absolute size from 0.1898% to 0.3407% protein content, jointly accounting for 43.45% of the trait variance. Conditional QTL mapping analysis indicated two QTL independent from yield, which can be used in marker-assisted selection for increasing yield without affecting grain protein content. Three additional QTL with minor effects were identified in the conditional mapping. Of the three QTLs, two were identified when protein content was conditioned on yield, which had pleiotropic effects on those two traits. Conditional QTL mapping can be used to dissect the genetic interrelationship between two traits at the individual QTL level for closely correlated traits. Further, conditional QTL mapping can reveal additional QTL with minor effects that are undetectable in unconditional mapping.