Sphaceloma poinsettiae as a potential biological control agent for wild poinsettia (Euphorbia heterophylla)

Sphaceloma poinsettiae, a scab-causing fungus that attacks wild poinsettia (Euphorbia heterophylla) was evaluated as a mycoherbicide. Plants representing nine different E. heterophylla accessions were tested and variable resistance levels to 10 different isolates of S. poinsettiae were observed. One isolate was selected based on its high aggressiveness; it caused scab that led to stem-girdling in the majority of plants belonging to most wild poinsettia accessions. Plants inoculated with conidial suspension developed low disease severity; suspensions of mycelial fragments caused higher disease severity. Viability of mycelium declined rapidly either in storage under room temperature or at 4 °C. After 25 days, 60% of mycelial fragments kept in distilled water at 4 °C or in 35% sterile sucrose solution germinated. Cultures of S. poinsettiae were capable of growing at temperatures ranging from 10 to 30 °C (maximum growth at 25 °C) whereas the mycelial fragments germinated at 20–30 °C. The highest mycelial yield occurred in potato-dextrose broth after culturing for 12 days at 168 rpm at room temperature. A host-range test involving 37 plant species in addition to wild poinsettia indicated that S. poinsettiae is highly specific to E. heterophylla. The viability of S. poinsettiae as a mycoherbicide depends on the development of suitable mass production, formulation, and inoculum preservation methods. On several occasions, this fungus has been observed to cause devastating epidemics in the field on this host; therefore, it should be considered a potential biocontrol agent of wild poinsettia.     

Mitochondrial DNA polymorphisms in a sample of Albanian population (Tirana)

RFLPs of mtDNA for HpaI, BamHI, HaeII, MspI, AvaII and HincII were analysed in a sample of 100 from collected in Tirana (Albania). Eighteen mtDNA types were identified, four of which are new: two because of new morphs for Hpa/HincII (HpaI-9^Tir/HincII-17^Tir) and AvaII (AvaII-35Tir), and two because of new associations between morphs which were already known. Albanian data were compared with corresponding ones from Calabrians (Southern Italians) and Arbreshes (people of Albanian ancestry living in Calabria). Even though the examined mtDNA markers do not reveal important differences among the three groups, the analysis of both morphs and types shows a trend which places Arbreshes closer to Calabrians than to Albanians.     

Y-chromosome-specific microsatellite variation in a population sample from Sardinia (Italy)

The genetic variability at seven Y-chromosomal microsatellite loci was studied among 113 Sardinian males from the regions of Campidano of Cagliari, Nuorese and Gallura. The allelic and haplotypes frequency distributions are compared between our sample and from the available literature data on Mediterranean and European populations. As a result, the Sardinian samples showed a very high allele frequency in the DYS19*17, a rarity in the rest of Europe, probably due to the founder effect. The analysis has shown an intra-population genetic heterogeneity and genetic differentiation from other Mediterranean and European population deal with. The results reported in this work showed that of the Euro-Mediterranean populations, the Corsican of the South seems to have the most genetic affinity with the Sardinians, thereby reaffirming the observations from previous works that had suggested a certain level of genetic similarity.     

The population genetic structure of Ctenomys porteousi (Rodentia: Octodontidae)

Several aspects of the population biology and the population genetic structure of Ctenomys porteousi were studied. Chromosomal and allozyme polymorphisms in two local populations separated by 10 km were used to infer genetic structure. Heterochromatic addition/deletion rearrangements for six autosomal pairs were employed as genetic markers. Allozyme variants were analysed by the study of thirty-one presumptive loci. Thirteen loci (43%) were polymorphic, average observed heterozygosity per locus was 10%, and mean number of alleles per locus was 1.57. Chromosomal and allozyme frequencies were homogeneous across populations. The estimated F_st values were very low, 0.009 and 0.022 for chromosomal and allozyme data respectively. Gene flow was indirectly estimated by the method of Wright, Nm values (mean number of migrants per generation per deme) was very high (27.2 and 11.3 for chromosomal and allozyme data respectively). The F_is values suggest a significant defect of heterozygotes that could be explained by the Wahlund effect. The ecological data indicate the occurrence of sharp changes in density and in distribution pattern in short time. The genetic and ecological data suggest that the population structure of C. porteousi differs from that found in other species of Ctenomys affected by chromosomal mechanisms of speciation.     

周氏啮小蜂(海南种群)对椰子织蛾的寄生功能反应

【目的】周氏啮小蜂(海南种群)是寄生椰子织蛾蛹期的本土天敌。研究周氏啮小蜂(海南种群)对椰子织蛾的功能反应,能为该蜂室内扩繁和室外控害利用提供基础。【方法】在室内观察周氏啮小蜂(海南种群)寄生行为基础上,研究了营养(10%蜂蜜)、寄主蛹(初、中、晚)期对周氏啮小蜂(海南种群)寄生功能反应的影响。【结果】镜下观察1头周氏啮小蜂(海南种群)可寄生多头椰子织蛾蛹,寄生量随寄主密度的增大而增加,但当寄主密度达到一定程度后,其增长率随寄主密度的增大逐渐减缓,属于HollingⅡ功能反应。在无营养条件下,周氏啮小蜂(海南种群)对椰子织蛾初、中、晚期蛹的理论最大寄生量分别为1.5、1.4、1.2头·d~(-1);在10%蜂蜜饲喂条件下,周氏啮小蜂(海南种群)对椰子织蛾初、中、晚期蛹的理论最大寄生量分别为1.8、1.7、1.3头·d~(-1)。【结论】HollingⅡ型拟合结果表明,椰子织蛾初期蛹是周氏啮小蜂(海南种群)寄生的最佳时期,补充营养能够提高椰子织蛾的寄生力。     

Historical demography of a wild lemur population (Propithecus verreauxi) in southwest Madagascar

The human colonization of Madagascar is associated with the extinction of numerous lemur species. However, the degree to which humans have negatively influenced the historical population dynamics of extant lemur species is not well understood. This study employs genetic and demographic analyses to estimate demographic parameters relating to the historical population dynamics of a wild lemur population, Verreaux’s sifaka (Propithecus verreauxi). The genetic analyses are used to determine whether this population experienced a historically recent (i.e., within the last 2000 years) population bottleneck, as well as to estimate the historical population growth rate and the timing of any changes in population size in the past. In addition, a retrospective demographic analysis is used to determine sources of variation and covariation in the sifaka life cycle and how variation in life-cycle transitions contributes to variation in population growth rate. The genetic analyses indicate that the sifaka population did not experience a recent population bottleneck; however, the historical population growth rate was negative, indicating that the ancestral population size was much larger than the current size. The timing of the ancestral population decline has a point estimate of 2300 years ago, but with large credible intervals: 3611–1736 years ago. This point estimate corresponds with the first evidence for human arrival to Madagascar. Climatic variation has also likely influenced past (and current) population dynamics due to stochastic annual rainfall patterns and climatic desiccation, the latter of which began in southwestern Madagascar around 4000 years ago. Variation in the survival of 2-year-old animals as well as large adult females makes the largest contribution to variation in population growth rate. In the absence of more explicit models pertaining to historical population dynamics, it is difficult to attribute the negative population growth rate of this species solely to a single factor (e.g., hunting, habitat destruction).     

The occurrence of haemosporidian parasites in the Fennoscandian bluethroat ( Luscinia svecica) population

A total of 86 adult bluethroats (Luscinia svecica) from nine different localities, covering the full length of the Fennoscandian mountain range, were screened for blood parasites of the three genera Haemoproteus, Plasmodium and Leucocytozoon using a recently developed polymerase chain reaction method. The overall occurrence of infection was 59.3%. Prevalence of Leucocytozoon spp. (47.7%), Plasmodium spp. (23.3%) and Haemoproteus spp. (1.2%) was detected. Of the infected birds, 15.1% carried mixed infections. Five different mitochondrial DNA-lineages of Leucocytozoon spp., eight lineages of Plasmodium spp. and one lineage of Haemoproteus spp. were found. Due to large sequence divergence these corresponded to at least five different species, but with the possibility of all 14 being independent evolutionary units with the potential of evolving different effects on the host. Of the lineages of Leucocytozoon spp., the most common was found throughout the range. The occurrence of the second most common lineage of Leucocytozoon spp. showed significant variation in prevalence between sites. The data also showed molecular evidence of one lineage of Leucocytozoon sp. existing in more than one species of avian host, thus challenging the use of host taxon as a taxonomic character when distinguishing between different species leucocytozoids.Communicated by F. Bairlein     

太子参谷胱甘肽-S-转移酶基因家族生物信息学及表达分析

GSTs (glutathione-S-transferases)是一个普遍存在于植物体内,多基因家族编码的多功能蛋白酶。为研究GSTs基因家族在太子参中对其生长发育以及活性成分合成调控的潜在功能,该文基于隐马尔可夫模型在太子参中鉴定到30个谷胱甘肽-S-转移酶(PhGSTs)的基因家族成员。结果表明:30个PhGSTs基因同时具有高度保守的N-端结构域和复杂多变的C-端结构域,分属于6个亚家族,有10个motif区,其中motif1、motif 2、motif 3同属于所有家族,motif 4仅属于Tua亚家族。PhGST蛋白质三级结构有明显的相似之处,N端主要由3个α螺旋和4个β折叠构成βαβαββα结构域,C端均由α螺旋构成,不同亚家族的C端α螺旋数目及组合方式各不相同,但始终维持相似的三维结构。PhGST基因在太子参植物中具有不同的组织表达特异性,PhGSTU1、PhGSTU8、PhGSTU9等在太子参块根中优势表达,PhGSTF2在茎和叶中优势表达。水分胁迫处理后有4个基因积极响应干旱胁迫,PhGSTZ1的响应最为明显;同时也有PhGSTU8、PhEFB1γ3等4个基因随土壤含水量增加呈上调表达。该文鉴定出30个PhGST基因,并分析了其在太子参中的表达模式,为PhGSTs基因家族在太子参活性成分的合成调控及逆境响应等生理过程中的功能研究奠定理论基础。     

The fate ofsepia in small populations ofDrosophila melanogaster

Asepia gene found inD. melanogaster collected in North Carolina, and wildtype flies from North Carolina, Bogotá, Barcelona, and California were used to strt 120 cultures that were maintained by mass transfers of adults every third week for more than a year. The frequency ofsepia was determined in these cultures at the termination of the experiment. Thesepia gene was present in considerable frequency (16%–65%) in all backgrounds except one; in cultures involving wildtype chromosomes from North Carolina, it was virtually eliminated. Each of the wildtype backgrounds exhibited a characteristic final frequency ofsepia, suggesting that they had reached at least quasi-stable equilibria. Although it is likely that the retention ofsepia depended upon the superiority of flies heterozygous for this mutant, the technique does not reveal whethersepia itself was involved in the apparent heterosis.The work reported here was done under Contract No. AT-(30-1)-2139, U. S. Atomic Energy Commission.     

Seasonal changes in a population of Menacanthuseurysternus (mallophaga, amblycera) on the common myna Acridotheres tristis

Seasonal changes in a population of Menacanthus eurysternus (Mallophaga, Amblycera) on the common myna Acridotheres trislis. International Journal for Parasitology20: 1063–1065. Seasonal variations in a population of an amblyceran louse, Menacanthus eurysternus, infesting the common myna have been studied. Incidence of infestation, lice, index, and population structure of this species have been recorded in different months of the year; reasons for the population fluctuations are discussed.     

濒危植物长柄双花木自然种群年龄结构及其生态对策

通过对濒危植物长柄双花木自然种群的年龄结构、图解生命表以及生殖价分析等途径,研究了其种群结构动态及生态对策,结果表明:长柄双花木种群为衰退型种群,虽然种群中也存在一定数量的幼龄个体,但个体死亡率较高。长柄双花木种群表现出r～K对策的混合生态适应策略。该种群数量在下降过程中还存在波动,仍具有一定的实现生殖和恢复的可能,但依靠有性生殖途径实现恢复的能力有限。     

G1m phenotypes in a sample population from Tirana (Albania)

This report presents the distribution of G1m phenotypes (allotypes z, a, x, f,) observed in a sample population from Tirana (Albania). The comparison between these data and those previously found in a sample group of Arbreshes (Albanians who live in South Italy where they immigrated about 4 centuries ago) showed that, at least for the tested markers, the cultural identity of Arbreshes is not reflected by a genetic isolation from Southern Italians.     

The effects of mullein plants (Verbascum thapsus) on the population dynamics of Dicyphus hesperus (Heteroptera: Miridae) in tomato greenhouses

The response of Dicyphus hesperus Knight (Heteroptera: Miridae) to whitefly populations in tomato greenhouses was measured in the presence and absence of mullein (Verbascum thapsus L.) as an alternative host plant. The dynamics of the D. hesperus population on tomato (Lycopersicon esculentum Mill.) and on mullein plants were followed through an entire growing season. In houses with mullein plants, more predators occurred on mullein when whitefly density was low on tomato. A mark-release-recapture experiment where rabbit IgG was used as an external marker showed that D. hesperus adults moved from mullein plants to tomato plants. D. hesperus was always more abundant in houses with mullein than in the houses with tomato plants alone. Movements between tomato and mullein plants are discussed as a strategy to optimize predator foraging. The use of mullein as an alternative host plant may contribute to the establishment of D. hesperus and help to preserve the predator population when prey on tomato crops is scarce.     

全国栽培太子参生态适宜性区划分析

采用Arc GIS地理信息系统软件的空间分析方法和SPSS统计软件的统计分析方法,分析了全国太子参潜在适宜种植地理分布、适宜生境及化学成分与环境因子的相关性。结果显示:采用聚类分析从46个样地中筛选出34个多糖含量较高的样地。所建模型经ROC曲线验证,预测效果非常好(AUC0.9)。最干月降水量(贡献率68.4%)、土壤类型(9.7%)、最暖季平均温(6.0%)、等温性(4.0%)是影响太子参种植分布最重要的环境因子,其最适宜生境范围为:最干月降水量20—60mm;最暖季平均温21.5—30.5℃;等温性18%—35%;土壤类型为不饱和薄层土、饱和粘磬土中的黄棕壤、黄壤、黄红壤。相关性分析显示,多糖和生境适宜度均与最湿季降水量、最暖季降水量、最暖季平均温、最干月降水量及年平均气温无显著相关性。太子参最适宜区主要分布在长江中下游区域,主要有贵州中部,重庆与湖南、湖北接壤处,河南南部,安徽西部,江苏中部,福建东北部以及浙江北部和东南部区域。因此,明确全国太子参潜在的适宜种植区可为太子参种植基地的选取和合理布局提供参考。     

The RHD variants in Chinese population

The Rhesus (Rh) blood group system is the most important blood group system in hemolytic disease of the fetus and newborn (HDFN). In clinical transfusions, the D antigen in the Rh blood group system comes third, behind antigens A and B which from ABO blood group system. Over the past decade, molecular technologies have been used to investigate the RHD allele in different ethnic groups. This review first introduces the basic structure of RhD protein and coding genes, then focuses on D-negative, weak D, partial D, DEL, RhD_null variants reported in the Chinese population. To date, more than 460 RHD variants have been reported around the world, but less than 70 RHD variants have been reported in the Chinese population. Further research is needed to identify more RHD polymorphism and establish criteria for blood detection and transfusion guidelines for RHD variants. Only in this way can we better guarantee the safety of blood transfusion and prevent the occurrence of HDFN. With the accumulation of research and clinical data, we should be clearer which RHD variants are to be regarded as RhD negative and which need to be regarded as RhD positive.     

Spatial behaviour of little owls (Athene noctua) in a declining low-density population in Denmark

Knowledge of a species’ spatial behaviour is essential for understanding its behavioural ecology, as well as a prerequisite to planning of conservation strategies. The Little Owl (Athene noctua) has shown a substantial decline in north-western Europe and is on the road of extinction in Denmark. To quantify relevant aspects of spatial behaviour in the last remaining Danish population, we followed 27 radio-tagged owls representing 14 territories during a period of 2 years. Mated owls were resident at nesting sites year-round with half of all nocturnal locations found within 125 m. Mean nightly distance from roosts peaked in January at 249 m (95% CI = 195–319) and dipped in May to 89 m (66–121). Distance from roosts varied non-linearly with temperature with the longest distances found at 6°C. Home range size varied with more than a tenfold difference between pairs, with pairs with neighbours maintaining 2–3 times larger ranges than isolated pairs independent of habitat composition. Mean home range size of 14 pairs was 41 (95% CI 27–64) and 2.6 ha (1.5–4.5) for 90 and 50% minimum convex polygons, respectively. Males and females behaved similarly, except in the breeding season where females foraged closer to the nest. Mates overlapped completely in activity distributions and were located closer to each other than expected by chance, suggesting a permanent pair-bond. Inter-mate distances were not shorter prior to egg laying compared to the rest of the year, indicating little male investment in mate guarding. No mates left their partner, but widowed birds left their territory within 6–12 months if unable to attract a new mate. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The Peniophorella praetermissa species complex (Basidiomycota)

The corticioid basidiomycete Peniophorella praetermissa has long been regarded as a morphologically variable species complex. An ITS-based phylogenetic study based on a worldwide sampling was carried out using parsimony and Bayesian inference. The resulting trees feature three major clades, further divided into well-supported subclades. These could be considered as distinct species, a contention that is further supported by crossing test data. Only two out of the eight phylogenetic lineages identified can be distinctly morphologically characterized: P. odontiaeformis and P. subpraetermissa. P. odontiaeformis is an odontioid species with a paleotropical distribution whereas the taxa in the remaining subclades have smooth basidiomata and are distributed in temperate areas. P. subpraetermissa is known only from the type collection and is distinguished microscopically by its reddish brown apically encrustated cystidia. Taxa in the remaining subclades are impossible to distinguish from each other morphologically, and therefore, are viewed as a species complex, P. praetermissa s. lat. One of the subclades, which is widely distributed but restricted to the Northern hemisphere, is proposed to represent P. praetermissa s. str. An epitype is selected from the same area as the holotype, among the specimens studied here. However, the geographically most widespread clade with many representatives from both hemispheres is here referred to as P. pertenuis, a taxon that was previously considered a synonym to P. praetermissa.     

Extracellular superoxide dismutase (EC-SOD) gene mutations screening in a sample of Mediterranean population

The main role of superoxide dismutases (SODs) is to eliminate reactive oxygen species in cells and tissues. Extracellular SOD (EC-SOD/SOD3) is a major superoxide scavenger and it is located on cell surfaces and primarily in extracellular matrix, and binds heparan sulfates by its carboxyterminal portion. Human EC-SOD gene is located on chromosome 4 and comprises three exons and two introns. The SOD3 coding sequence is entirely located within exon 3 and has missense polymorphisms. The Arg213Gly mutation affects the function of the carboxyterminus and correlates with several diseases. In this work, we explored genetic variants within EC-SOD gene of subjects living in southern Italy. Four new variations were detected: one was silent mutation, while three were missense variations that give rise to amino acid substitutions at position 131 (F>C), 160 (V>L) and 202 (R>L) in the mature product. The Arg213Gly variant was not found. The missense mutations in the DNA of assayed 2400 chromosomes had frequencies of 5.34% for the F131C variation, 0.25% for the V160L variation and 0.84% for the R202L variation. The effect of these alterations on the metabolic activity and diseases remains to be further explained.