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41.
Distinct sources of gene flow produce contrasting population genetic dynamics at different range boundaries of a Choristoneura budworm
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Gwylim S. Blackburn Bryan M. T. Brunet Kevin Muirhead Michel Cusson Catherine Béliveau Roger C. Levesque Lisa M. Lumley Felix A. H. Sperling 《Molecular ecology》2017,26(23):6666-6684
Populations are often exposed to multiple sources of gene flow, but accounts are lacking of the population genetic dynamics that result from these interactions or their effects on local evolution. Using a genomic clines framework applied to 1,195 single nucleotide polymorphisms, we documented genomewide, locus‐specific patterns of introgression between Choristoneura occidentalis biennis spruce budworms and two ecologically divergent relatives, C. o. occidentalis and Choristoneura fumiferana, that it interacts with at alternate boundaries of its range. We observe contrasting hybrid indexes between the two hybrid zones, no overlap in “gene‐flow outliers” (clines showing relatively extreme extents or rates of locus‐specific introgression) and variable linkage disequilibrium among those outliers. At the same time, correlated genomewide rates of introgression between zones suggest the presence of processes common to both boundaries. These findings highlight the contrasting population genetic dynamics that can occur at separate frontiers of a single population, while also suggesting that shared patterns may frequently accompany cases of divergence‐with‐gene‐flow that involve a lineage in common. Our results point to potentially complex evolutionary outcomes for populations experiencing multiple sources of gene flow. 相似文献
42.
Composition and Biological Activity of Picea pungens and Picea orientalis Seed and Cone Essential Oils
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Anna Wajs‐Bonikowska Łukasz Szoka Ewa Karna Anna Wiktorowska‐Owczarek Monika Sienkiewicz 《化学与生物多样性》2017,14(3)
The increasing consumption of natural products lead us to discover and study new plant materials, such as conifer seeds and cones, which could be easily available from the forest industry as a waste material, for their potential uses. The chemical composition of the essential oils of Picea pungens and Picea orientalis was fully characterized by GC and GC/MS methods. Seed and cone oils of both tree species were composed mainly of monoterpene hydrocarbons, among which limonene, α‐ and β‐pinene were the major, but in different proportions in the examined conifer essential oils. The levorotary form of chiral monoterpene molecules was predominant over the dextrorotary form. The composition of oils from P. pungens seeds and cones was similar, while the hydrodistilled oils of P. orientalis seeds and cones differed from each other, mainly by a higher amount of oxygenated derivatives of monoterpenes and by other higher molar mass terpenes in seed oil. The essential oils showed mild antimicrobial action, however P. orientalis cone oil exhibited stronger antimicrobial properties against tested bacterial species than those of P. pungens. Effects of the tested cone essential oils on human skin fibroblasts and microvascular endothelial cells (HMEC‐1) were similar: in a concentration of 0 – 0.075 μl/ml the oils were rather safe for human skin fibroblasts and 0 – 0.005 μl/ml for HMEC‐1 cells. IC50 value of Picea pungens oils was 0.115 μl/ml, while that of Picea orientalis was 0.105 μl/ml. The value of IC50 of both oils were 0.035 μl/ml for HMEC‐1 cells. The strongest effect on cell viability had the oil from Picea orientalis cones, while on DNA synthesis the oil from Picea pungens cones. 相似文献
43.
44.
van Frankenhuyzen K Ryall K Liu Y Meating J Bolan P Scarr T 《Journal of invertebrate pathology》2011,108(3):201-208
Microsporidia are believed to play little or no role in outbreaks of the jack pine budworm, Choristoneura pinuspinus Freeman (Lepidoptrera: Tortricidae), because the short duration (2–4 years) of those outbreaks may not permit significant build-up of the pathogen. We conducted the first survey of Nosema sp. (Microsporidia: Nosematidae) over the course of a recent jack pine budworm outbreak in Ontario. Between 2004 and 2010 the outbreak defoliated a cumulative total of 1.78 million ha. Microscopic examination of ∼15,000 overwintering larvae collected over 6 years in sites with densities of 3 larvae per branch or more revealed widespread occurrence of Nosema at generally high infection intensities. The pathogen was present in 69.5% of the 518 plots that were monitored. Prevalence of infection was generally low (below 40% in 84% of plots with infected larvae) but reached high levels (80–95%) locally and increased rapidly in most infestations within 1–2 years of onset. We hypothesize that the habit of early-instar larvae to feed on developing male flowers (pollen cones) after spring emergence is critical in allowing rapid build-up of Nosema by increasing efficiency of horizontal transmission (higher density of both infected larvae and egested spores). Nosema infection may contribute to the complexity of jack pine budworm outbreak patterns by affecting egg recruitment and early-instar survival at the stand level in concert with known effects of budworm-induced reductions in pollen cone production on those processes. 相似文献
45.
雄性棉铃虫和烟青虫对雌性信息素的触角电生理反应 总被引:6,自引:0,他引:6
利用触角电位图(Electroantennogram,EAG)技术,比较研究了二近缘种棉铃虫、烟青虫对其性信息素主要成分Z—11—16:Ald、Z—9—16:Ald的触角电生理反应。剂量反应曲线表明,对Z—11—16:Ald,棉铃虫和烟青虫均有明显的EAG反应,且随浓度的增加而增强,但棉铃虫比烟青虫的反应较强;对Z—9—16:Ald,烟青虫有很强的EAG反应,棉铃虫的反应则很弱;对Z—11—16:Ald和Z—9—16:Ald以97:3和7:93比例形成的混合物,棉铃虫、烟青虫均有EAG反应,但二者之间没有显著差异[动物学报49(6):795~799,2003]。 相似文献
46.
Estimating the uptake of traffic-derived NO2 from 15N abundance in Norway spruce needles 总被引:1,自引:0,他引:1
The 15N ratio of nitrogen oxides (NOx) emitted from vehicles, measured in the air adjacent to a highway in the Swiss Middle Land, was very high [δ15N(NO2) = +5.7‰]. This high 15N abundance was used to estimate long-term NO2 dry deposition into a forest ecosystem by measuring δ15N in the needles and the soil of potted and autochthonous spruce trees [Picea abies (L.) Karst] exposed to NO2 in a transect orthogonal to the highway. δ15N in the current-year needles of potted trees was 2.0‰ higher than that of the control after 4 months of exposure close to
the highway, suggesting a 25% contribution to the N-nutrition of these needles. Needle fall into the pots was prevented by
grids placed above the soil, while the continuous decomposition of needle litter below the autochthonous trees over previous
years has increased δ15N values in the soil, resulting in parallel gradients of δ15N in soil and needles with distance from the highway. Estimates of NO2 uptake into needles obtained from the δ15N data were significantly correlated with the inputs calculated with a shoot gas exchange model based on a parameterisation
widely used in deposition modelling. Therefore, we provide an indication of estimated N inputs to forest ecosystems via dry
deposition of NO2 at the receptor level under field conditions.
Received: 7 November 1997 / Accepted: 16 September 1998 相似文献
47.
Colonisation of spruce roots by two interacting ectomycorrhizal fungi in wood ash amended substrates
Mahmood S 《FEMS microbiology letters》2003,221(1):81-87
Interactions between two ectomycorrhizal fungal species, Piloderma croceum Erikss. and Hjortst. and Piloderma sp. 1 (found to colonise spruce roots and wood ash granules in the field), were investigated in wood ash amended substrates. The comparative ability of these fungi to colonise roots of non-mycorrhizal spruce (Picea abies (L.) Karst.) seedlings was studied in relation to factorial combinations of wood ash and N fertilisation. Non-mycorrhizal spruce seedlings (bait seedlings) were planted together with spruce seedlings colonised by P. croceum or Piloderma sp. 1. The growth substrate was a sand-peat mixture with wood ash or no ash and supplied with two levels of N, so that four substrate combinations were obtained. Piloderma sp. 1 mycelia colonised around 60% of the fine roots of bait seedlings in ash treatments regardless of N level and around 20-26% in treatments without ash. P. croceum only colonised 8% of the root tips in the presence of ash but 56% of the root tips in the low-N treatment without ash. However, in the high-N treatment without ash the colonisation level was reduced to around 30%. Total numbers of root tips per seedling did not vary significantly between the treatments. Possible reasons for the competitive advantage of Piloderma sp. 1 in wood ash fertilised substrate are discussed. 相似文献
48.
The TTAA-specific lepidopteran transposon piggyBac has already proved useful as a gene-transfer vector for efficient transformation of a wide variety of insects. Transposable element excision and transposition assays are useful indicators of an element's ability to be mobilized in vivo and, thus, potentially serve as a transforming vector. Here, we report that this transposon is capable of excision and transposition in tobacco budworm embryos with relatively low frequency. 相似文献
49.
We have measured the uptake capacity of nitrogen (N) and potassium (K) from different soil depths by injecting 15N and caesium (Cs; as an analogue to K) at 5 and 50 cm soil depth and analysing the recovery of these markers in foliage and buds. The study was performed in monocultures of 40-year-old pedunculate oak (Quercus robur), European beech (Fagus sylvatica) and Norway spruce (Picea abies (L.) Karst.) located at an experimental site in Palsgård, Denmark. The markers were injected as a solution through plastic tubes around 20 trees of each species at either 5 or 50 cm soil depth in June 2003. After 65 days foliage and buds were harvested and the concentrations of 15N and Cs analysed. The recovery of 15N in the foliage and buds tended to be higher from 5 than 50 cm soil depth in oak whereas they where similar in spruce and beech after compensation for differences in immobilization of 15N in the soil. In oak more Cs was recovered from 5 than from 50 cm soil depth whereas in beech and spruce no difference could be detected. Out of the three investigated tree species, oak was found to have the lowest capacity to take up Cs at 50 cm soil depth compared to 5 cm soil depth also after compensating for differences in discrimination against Cs by the roots. The uptake capacity from 50 cm soil depth compared with 5 cm was higher than expected from the root distribution except for K in oak, which can probably be explained by a considerable overlap of the uptake zones around the roots and mycorrhizal hyphae in the topsoil. The study also shows that fine roots at different soil depths with different physiological properties can influence the nutrient uptake of trees. Estimates of fine root distribution alone may thus not reflect the nutrient uptake capacity of trees with sufficient accuracy. Our study shows that deep-rooted trees such as oak may have lower nutrient uptake capacity at deeper soil layers than more shallow-rooted trees such as spruce, as we found no evidence that deep-rooted trees obtained proportionally more nutrients from deeper soil layers. This has implications for models of nutrient cycling in forest ecosystems that use the distribution of roots as the sole criterion for predicting uptake of nutrients from different soil depths. 相似文献
50.
The rate and temporal pattern of pheromone emission by single and grouped female spruce budworm moths were measured by combining the trapping of pheromone on Porapak Q with a rapid luciferase bioassay developed for aldehyde pheromone. Pheromone release occurred mainly during the scotophase of a 12:12 L:D cycle in a series of bursts (up to 50 ng/hr) with considerable variability observed between insects. Analysis of over 30 individual females showed that 30% release no detectable pheromone, 60% release between 20 and 100 ng of pheromone and 10% release greater than 100 ng in a 24-hr period. Overall, a single female (1–3 days old) released an average of 60 ± 50 ng (± S.D.) of pheromone per night with a total of 260 ± 210 ng (± S.D.) being released over its life span (~7 days). Grouped females released lower quantities of pheromone. The amount of pheromone in the glands of female moths also displayed a rhythm with the levels beings higher later in the day than at the start of the photophase. 相似文献