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1.
Ana M. Vieitez Elena Corredoira M. Teresa Martínez M. Carmen San-José Conchi Sánchez Silvia Valladares Nieves Vidal Antonio Ballester 《European Journal of Forest Research》2012,131(3):519-539
The genus Quercus, which belongs to the family Fagaceae, is native to the northern hemisphere and includes deciduous and evergreen species. The trees of the different species are
very important from both economic and ecological perspectives. Application of new technological approaches (which span the
fields of plant developmental biology, genetic transformation, conservation of elite germplasm and discovery of genes associated
with complex multigenic traits) to these long-rotation hardwoods may be of interest for accelerating tree improvement programs.
This review provides a summary of the advances made in the application of biotechnological tools to specific oak species.
Significant progress has been made in the area of clonal propagation via organogenesis and somatic embryogenesis (SE). Standardized
procedures have been developed for micropropagating the most important European (Q. robur, Q. petarea, Q. suber) and American (Q. alba, Q. bicolor, Q. rubra) oaks by axillary shoot growth. Although regenerated plantlets are grown in experimental trials, large-scale propagation
of oak species has not been carried out. The induction of SE in oaks from juvenile explants is generally not problematic,
although the use of explants other than zygotic embryos is much less efficient. During the last decade, enormous advances
have been made in inducing SE from selected adult trees, mainly specimens of pedunculate oak (Q. robur) and cork oak (Q. suber). Advances in the understanding of the maturation and germination steps are required for better use of embryogenic process
in clonal forestry. Quercus species are late-maturing and late-flowering, exhibit irregular seed set, and produce seeds that are recalcitrant to storage
by conventional procedures. Vitrification-based cryopreservation techniques were used successfully in somatic embryos of pedunculate
oak and cork oak, and an applied genbank of cork oak selected genotypes is now under development. The feasibility of genetic
transformation of pedunculate oak and cork oak somatic embryos by means of co-culture techniques with several strains of Agrobacterium tumefaciens has also been demonstrated. To date, most research on the genomics of Quercus species has concerned population genetics. Approaches using functional genomics to examine the molecular and cellular mechanisms
that control organogenesis and or somatic embryogenesis are still scarce, and efforts on the isolation and characterization
of genes related to other specific traits should be intensified in the near future, as this would help improve the practical
application of clonal forestry in recalcitrant species such as oaks. 相似文献
2.
Quercus robur L. and Quercus petraea (Matt.) Liebl. are sympatric oak species with different ecological requirements. Quercus robur is more tolerant to waterlogging than Q. petraea. This ecological divergence may play a role in the maintenance of the two species despite the absence of an insurmountable reproductive barrier between them. We predicted that the genetic architecture of traits related to waterlogging tolerance differs between the species. To gain insight into this architecture in the absence of genetic markers for waterlogging tolerance, we compared populations of seedlings of each species for diversity in the expression of quantitative phenotypic traits induced by severe hypoxia. To determine the capacity for hypertrophied lenticel formation, we applied gas-impermeable mastic to stems of seedlings. Two months after application, the mastic treatment had induced the formation of 3 (+/- 2) cm(-2) hypertrophied lenticels in the absence of root hypoxia. Leaf epinasty during root hypoxia was an early predictor of seedling mortality. Four weeks of waterlogging resulted in greater epinasty in Q. petraea than in Q. robur, but fewer hypertrophied lenticels (16 +/- 6 versus 21 +/- 9 cm(-2)) and adventitious roots (2.7 +/- 4.7 versus 5.2 +/- 5.9). Differences between species in these traits were associated with differences in the frequencies of extreme phenotypes rather than with a generally higher tolerance to waterlogging in Q. robur seedlings. 相似文献
3.
The evergreen Quercus alnifolia and Q. coccifera form the only interfertile pair of oak species growing in Cyprus. Hybridization between the two species has already been
observed and studied morphologically. However, little evidence exists about the extent of genetic introgression. In the present
study, we aimed to study the effects of introgressive hybridization mutually on both chloroplast and nuclear genomes. We sampled
both pure and mixed populations of Q. alnifolia and Q. coccifera from several locations across their distribution area in Cyprus. We analyzed the genetic variation within and between species
by conducting analysis of molecular variance (AMOVA) based on nuclear microsatellites. Population genetic structure and levels
of admixture were studied by means of a Bayesian analysis (STRUCTURE simulation analysis). Chloroplast DNA microsatellites
were used for a spatial analysis of genetic barriers. The main part of the nuclear genetic variation was explained by partition
into species groups. High interspecific differentiation and low admixture of nuclear genomes, both in pure and mixed populations,
support limited genetic introgression between Q. alnifolia and Q. coccifera in Cyprus. On the contrary, chloroplast DNA haplotypes were shared between the species and were locally structured suggesting
cytoplasmic introgression. Occasional hybridization events followed by backcrossings with both parental species might lead
to this pattern of genetic differentiation. 相似文献
4.
D. E. L. Cooke T. Jung N. A. Williams R. Schubert W. Oßwald J. M. Duncan 《Forest Pathology》2005,35(1):57-70
The recently discovered oak‐specific fine root plant pathogen Phytophthora quercina is a significant factor in the current phase of European oak decline but its origins and ecology are poorly understood. A genome‐wide analysis of 260 amplified fragment length polymorphism (AFLP) markers was used to examine the genetic diversity of 72 isolates from five oak species at 28 sites in Germany (particularly Bavaria), Italy, France, Hungary and the UK. Within‐site diversity was examined at 16 sites. The limited genetic diversity (within and between sites) and lack of genetic substructuring according to geographic origin or host species suggest the rapid spread of a relatively recently introduced species. Two subgroups were distinguished and these may reflect an initial introduction of isolates of two different genetic backgrounds. The relatively low genetic diversity is probably because of the predominantly inbreeding (homothallic) nature of P. quercina. However, evidence of limited intra‐site diversity, temporal variation and the lack of clonality within the European population suggest that some diversity is being maintained by occasional outcrossing and turnover of a reservoir of long‐lived soil‐borne oospore (sexually derived) inoculum. 相似文献
5.
The phenotypic responses of functional traits in natural populations are driven by genetic diversity and phenotypic plasticity. These two mechanisms enable trees to cope with rapid climate change. We studied two European temperate tree species (sessile oak and European beech), focusing on (i) in situ variations of leaf functional traits (morphological and physiological) along two altitudinal gradients and (ii) the extent to which these variations were under environmental and/or genetic control using a common garden experiment. For all traits, altitudinal trends tended to be highly consistent between species and transects. For both species, leaf mass per area displayed a positive linear correlation with altitude, whereas leaf size was negatively correlated with altitude. We also observed a significant increase in leaf physiological performance with increasing altitude: populations at high altitudes had higher maximum rates of assimilation, stomatal conductance and leaf nitrogen content than those at low altitudes. In the common garden experiment, genetic differentiation between populations accounted for 0-28% of total phenotypic variation. However, only two traits (leaf mass per area and nitrogen content) exhibited a significant cline. The combination of in situ and common garden experiments used here made it possible to demonstrate, for both species, a weaker effect of genetic variation than of variations in natural conditions, suggesting a strong effect of the environment on leaf functional traits. Finally, we demonstrated that intrapopulation variability was systematically higher than interpopulation variability, whatever the functional trait considered, indicating a high potential capacity to adapt to climate change. 相似文献
6.
Sara Maltez-Mouro Luis V. García Helena Freitas 《European Journal of Forest Research》2009,128(1):27-36
We investigated the regeneration requirements of the two dominant tree species in a mixed-oak forest of SW Portugal: Quercus suber (cork oak, evergreen) and Q.
faginea (Portuguese oak, winter-deciduous). We hypothesized that (1) recruits of different oak species are differentially influenced
by soil and overstory variables and (2) different factors explain the recruitment occurrence and performance of the same species.
We sampled the recruits’ height and diameter, and several environmental and forest structure variables of their microsites.
Both recruitment occurrence and performance were modeled using generalized linear models. Our final models predicted the probability
of occurrence of recruits of Q. faginea and Q. suber with 74 and 82% of accuracy, respectively, and explained about 50% of the variance of their recruitment performance. The
recruits of Q. faginea tended to occur in microsites with higher canopy height, canopy density and litter cover, and closer to both conspecific
and heterospecific adults, while the opposite was true for recruits of Q. suber. The performance of recruits of Q. suber was favored by the higher litter cover (a good surrogate for N and P availability), but negatively affected by the higher
litter depth. We concluded the following: (1) there were significantly different regeneration niches for each species (Q. faginea and Q. suber); (2) the factors explaining the recruitment occurrence differed from those explaining the recruitment performance; (3) the
overstory plays a complex and important role in the regeneration process; (4) different variables apparently related with
the same environmental factor (e.g. litter cover and litter depth) could affect recruits in an opposite way; (5) sensitive
trade-offs must be considered for delineating management actions, since they could favor the regeneration of Q. suber, but, at the same time, negatively affect the regeneration of Q. faginea. 相似文献
7.
To clarify the effects of asynchronous seed production among tree species on the population of seed predators, we investigated
the relationship between the annual variation in production of mature acorns and the insect damage in those acorns of two
sympatric oak species, Quercus variabilis Blume and Quercus serrata Thunb. ex Murray, over 4 years at two study sites. The annual variation in acorn production was noticeable, with a coefficient
of variation (CV) at the two sites of 1.05 and 0.80 for Q. variabilis and 0.87 and 0.73 for Q. serrata. Annual fluctuation in acorn production by Q. serrata was synchronized between the two sites. Since annual fluctuation in acorn production was not synchronized between the two
species, the CVs for the total acorn production by both oak species (0.83 and 0.62 at the two sites) were lower than those
for Q. variabilis and Q. serrata alone. The rate of predation by the specialist predators (Curculio weevils) on the acorns of both species was not related to the annual acorn crop size. Prolonged diapause of Curculio weevils might stabilize their populations. The rate of acorn predation by the generalist predators (tortricid moths) was
also not related to the annual crop size. Asynchronous acorn production by the two oak species would help to stabilize the
population. 相似文献
8.
E. Tovar-Sánchez L. Valencia-Cuevas E. Castillo-Mendoza P. Mussali-Galante R. V. Pérez-Ruiz A. Mendoza 《European Journal of Forest Research》2013,132(1):165-179
Numerous oak species have wide geographical distribution and canopy dominance and they may influence the structure and functioning of the community. Therefore, they can be considered as foundation species. In the present study, we tested the potential association between individual genetic diversity of the host plant (microsatellites), host tree species (Quercus castanea and Q. crassipes), and seasonality (dry vs. rainy) with their arthropod community structure [diversity (H′), density, biomass and composition]. Forty individual oak canopies were fogged (10 individuals per species per season) in the Parque Ecológico Ciudad de México. We identified 338 arthropod morphospecies belonging to 21 orders. NMDS showed a separation of host tree species during both seasons, suggesting a different community structure between host tree species. Q. crassipes showed the highest values for H′, richness, and density in comparison with Q. castanea. In contrast, Q. castanea showed the highest values for arthropod biomass. Homozygosity by locus index (HL), a measure of individual diversity, showed that the more genetically diverse host individuals registered more H′ and density of arthropods, independently of the season. On the contrary, arthropod biomass registered an inverse pattern. This study suggests that genetic diversity of foundation species is an important element in the structuring of the canopy arthropod community. 相似文献
9.
A survey on the occurrence of Phytophthora species in oak ecosystems in Austria was conducted from April to May 1999 and in June 2000. The investigations were carried out at 35 study sites distributed throughout the zone of oak forests in eastern Austria. Four oak species, including Quercus robur, Q. petraea, Q. cerris and Q. pubescens were considered in the survey. Rhizosphere soil samples were taken from sample trees, which consisted of healthy and declining trees as indicated by their crown transparency. Young oak leaflets were used as baits to recover Phytophthora species. The assemblage of Phytophthora spp. detected in Austrian oak forests consisted of five species, including Phytophthora quercina, P. citricola, P. gonapodyides, P. europaea and P. syringae. P. quercina and P. citricola were isolated from 11 and seven sites, respectively, and were thus the most common and most widely distributed species. The three other species were recovered only sporadically. P. citricola could be separated into two morphologically and genetically well‐characterized types (A and B). Phytophthora species, in particular the common P. quercina and P. citricola occurred on sites showing a wide variety of soil types, soil textures and moisture classes. There was mild evidence for connection between deteriorating crown status and the presence of Phytophthora spp. Furthermore, significant differences in contents of magnesium, as well as calcium, aluminium, nitrogen and carbon at different soil depths (0–10, 10–20 and 20–40 cm) were detected between Phytophthora‐infested and Phytophthora‐free sites. The results of the present study provide circumstantial evidence that Phytophthora species are involved in oak decline at certain sites in Austria. 相似文献
10.
Sakina Elshibli Juha Raisio Saila Varis Pekka Vakkari Pertti Pulkkinen 《Scandinavian Journal of Forest Research》2016,31(2):140-147
We present a genetic profile of pedunculate oak (Quercus robur L.) in three woodlands of the Helsinki region. We genotyped all mature trees and samples of seedlings to evaluate patterns of genetic variation and gene flow, and evaluate the long-term stability and natural regeneration of these stands. Although five microsatellite loci showed no significant differences in heterozygosity between generations in most locations, significant (p?.05) pairwise differences were observed between mature trees and seedlings at Seurasaari, with higher diversity within seedlings. Ninety-four percent of the genetic variation occurred within sample sites. Background pollination contributed up to 61% of the diversity among seedlings, and thereby plays an important role in shaping the genetic variation and structure of future generations. Results indicate that pedunculate oak trees in the surveyed parks of Helsinki belong to the same population and that the urban environment per se does not interfere with gene flow over the distances represented here. Based on our findings, a minimal-maintenance program reliant upon natural regeneration of oak in the public parks of Helsinki seems plausible. 相似文献
11.
Charalambos Neophytou Filippos A. Aravanopoulos Siegfried Fink Aikaterini Dounavi 《European Journal of Forest Research》2011,130(4):623-635
Hybridization and introgression between Quercus alnifolia Poech and Q. coccifera L. is studied by analyzing morphological traits, nuclear and chloroplast DNA markers. The study site is a mixed stand on
Troodos Mountains (Cyprus), and the analyzed material includes both adult trees and progenies of specific mother trees. Multivariate
analysis of morphological traits shows that the two species can be well distinguished using simple leaf morphometric parameters.
A lower genetic diversity in Q. alnifolia than in Q. coccifera and a high interspecific differentiation between the two species are supported by an analysis of nuclear and chloroplast
microsatellites. The intermediacy of the four designated hybrids is verified by both leaf morphometric and genetic data. Analysis
of progeny arrays provides evidence that interspecific crossings are rare. This finding is further supported by limited introgression
of chloroplast genomes. Reproductive barriers (e.g. asynchronous phenology, postzygotic incompatibilities) might account for
this result. A directionality of interspecific gene flow is indicated by a genetic assignment analysis of effective pollen
clouds with Q. alnifolia acting as pollen donor. Differences in flowering phenology and species distribution in the stand may have influenced the
direction of gene flow and the genetic differentiation among effective pollen clouds of different mother trees within species. 相似文献
12.
The composition of the endophytic fungal assemblages in Quercus cerris, Q. pubescens and Q. robur, three oak species most susceptible to decline, was investigated in Fagarè (Padova), Ulignano (Pisa), and Radda in Chianti (Firenze). The endophytic assemblages were studied as a function of health status of the whole tree and of twigs and leaves. The effect of station altitude was tested on Q. cerris. Samples were gathered from healthy and declining trees. In April (bud opening time) 20 twigs and 10 leaves were collected from each tree. Fungi were isolated from twig segments and leaf portions. A total of 23 fungal genera with 27 different species were isolated, in addition to a few sterile mycelia. Eleven species were found to be common to all three oak species, while other species were found only on one oak species, suggesting host specificity. Among the fungal species isolated, some were known to be pathogenic (Apiognomonia quercina, Colpoma quercinum, Diplodia mutila, Phomopsis quercina). The colonization frequency (CF) of pathogenic species varied between 0.9% for A. quercina in Q. cerris and 60.2% for P. quercina in Q. robur. Analysis of variance showed a statistically significant difference among the oak species tested. The CF was higher in declining trees in comparison with healthy trees, and also in twigs vs. leaves. The CF was found to be higher for Q. cerris trees growing at sea level as compared with those situated at an elevation of 350–400 m. In stands where, on account of particular ecological conditions, pathogenic behaviour is displayed simultaneously by more than one endophytic fungal species, trees accentuate their decline. 相似文献
13.
《Scandinavian Journal of Forest Research》2012,27(2):103-116
Native Danish oak stands are fragmented and decreasing because of the extensive use of foreign seed sources. Therefore, the population structure of natural Danish oak stands was analysed by means of six polymorphic enzyme loci. A total of 17 stands of Quercus robur L. (including an ''outgroup'' sample from The Netherlands), seven Quercus petraea [Matt.] Liebl. and two putative hybrid stands were included in the study. The average genetic diversity was similar for the two species as well as for the putative hybrid stands: 0.25 for Q. robur, 0.27 for Q. petraea and 0.26 for the hybrid stands. The genotypic proportions at two (Pgm and Mnr) of the six loci showed many significant deviations from Hardy-Weinberg expectations, always with an excess of homozygotes, whereas the remaining four loci accorded to Hardy-Weinberg proportions, suggesting a low level of inbreeding. The differentiation of the Q. petraea and Q. robur populations was quantified with Wright's F-statistics. The within-species component was low, 0.022, reflecting the wind-pollinated reproductive mode of the two species. The betweenspecies component was 10-fold higher, 0.235, indicating two separate groups. A phylogenetic tree estimated from allele frequencies also supported the presence of these two groups. Despite the two well-separated groups in the tree, it was not possible to assign all individuals to the species to which they supposedly belonged. In total, 10% of the Q. robur individuals and 14% of the Q. petraea individuals were assigned to the other species, suggesting a limited amount of introgression between the two species. 相似文献
14.
从美国东南部引进属于红栎组的纳塔栎、舒玛栎、水栎、柳叶栎和属于白栎组的弗栎,在我国长江三角洲平原地区多个地点和不同土壤类型条件下进行造林研究.采用1~2年生裸根苗经长途运输后进行栽种,纳塔栎、舒玛栎和水栎成活率达94%以上,柳叶栎为76%~81%,弗栎仅42%~50%.不同树种之间,幼年阶段的根系发育、枝梢生长习性、秋冬叶色变化和虫害状况存在明显差异.在3~6个地点水稻土上建立的前4种栎树人工林,8~10a后在保留密度900~1 500株·hm-2条件下,其年均径生长量和年均高生长量达到0.96~1.76 cm和0.8~1.33 m.在山坡红黄壤地上栽种的纳塔栎、舒玛栎和柳叶栎,其年均径生长量和年均高生长量分别为0.64~1.01cm和0.57~0.78 m.采用2~4年生带土弗栎苗在6个地点滨海盐土上造林的成活率达87%以上,在保留密度1 110~3 900株·hm-2条件下,其7~9 a林木年均径生长量和年均高生长量分别为0.78~1.13 cm和0.59~0.75 m.当树龄达6~9 a时,5种栎树均开始结实.研究表明,5种北美栎树在长江三角洲地区有较强的适应性,水栎、纳塔栎、舒玛栎、柳叶栎可以应用于平原地区生态景观林和城镇园林绿化建设,而弗栎在沿海防护林建设中具有推广前景. 相似文献
15.
Francisco J. Baquedano Fernando Valladares Federico J. Castillo 《European Journal of Forest Research》2008,127(6):495-506
The Mediterranean evergreen woody plants Quercus coccifera and Pinus halepensis grow in a range of environments where selection by drought, heat and high irradiance can drive genetic and phenotypic differentiation
of populations. However, the role of these stresses in filtering out maladaptive genotypes remains unknown. We hypothesize
that this filtering is an important process for woody Mediterranean species due to their low phenotypic plasticity reported
in previous studies. We have studied the response of saplings of Q. coccifera and P. halepensis, originating from two contrasting populations (a rock outcrop and a garrigue formation), to water stress. Isozyme characterization
of genetic diversity was done to determine whether populations were genetically distinct. Water response analysis was based
on water relations, gas exchange, chlorophyll a fluorescence, pigment content, antioxidant status and morphological and structural parameters. Ecotypic differentiation was
found for both Q. coccifera and P. halepensis populations, with a higher population isozyme similarity and a higher frequency of dominance of a few genotypes at the rock
outcrop in both the species. P. halepensis exhibited small but significant differences between populations for plastic responses to water, with lower phenotypic plasticity
in saplings from the rock outcrop. Although it was not found in Q. coccifera, this pattern suggests that ecotypic differentiation rendering stress-tolerant ecotypes involves a decreased plasticity. Phenotypic
plasticity was not high but it explained over 75% of the total variability among individual plants. Thus, and although evidence
for ecotypic divergence was found in both the species, saplings were plastic enough to blur ecotypic differentiation.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
16.
[目的]利用表型性状和分子标记,对我国油橄榄品种进行鉴定和遗传多样性研究,有利于种质资源保存和利用,对了解油橄榄品种的组成结构及未来的引种和育种工作都具有重要意义。[方法]以甘肃省陇南市17个油橄榄品种为研究材料,利用表型上15个数量性状、18个质量性状和8个SSR荧光标记分别进行多样性和聚类分析。[结果]各性状在品种间存在显著差异,数量性状和质量性状的表型多样性指数分别介于1.579 2.089和0.3621.091,8个SSR位点共检测到51个等位基因变异,平均每个位点等位基因数为6.375个,利用表型性状和SSR标记可以将17个品种完全区分开。[结论]17个油橄榄品种具有较丰富的表型和遗传多样性,基于表型数量性状、质量性状和SSR标记的聚类分析结果,判别品种间遗传关系的结果有一致的,也存在一定差异。对于表型性状相似的品种,需结合SSR标记进行品种鉴定。 相似文献
17.
In the United States, diseased oaks (Quercus species) exhibit tip blight, branch and stem cankers, and dieback often attributed to Diplodia species or related fungi. Emergence of Diplodia corticola as a pathogen of European oaks, and reports of this fungus in the eastern and western United States, prompted re‐examination of strains from Wisconsin. These had been obtained in the late 1990s and early 2000s and previously identified only as Diplodia species. Nuclear ribosomal ITS sequences were obtained from the Wisconsin strains and analysed with other sequences from GenBank. Wisconsin strains confirmed as D. corticola were from northern red oak (Q. rubra), black oak (Q. velutina), white oak (Q. alba) and bur oak (Q. macrocarpa). Other strains from oaks in Wisconsin were D. mutila and D. seriata. Wound inoculation of northern red, white and bur oak seedlings with D. corticola in a greenhouse resulted in shoot death and stem lesions, from which the pathogen was reisolated. We conclude that D. corticola has been present in the northcentral United States for at least two decades and report two previously unrecognized hosts of this pathogen: white oak and bur oak. The roles of D. corticola, related fungi and influences of other environmental factors in deterioration of oak health in North America merit additional investigation. 相似文献
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20.
Christopher Baraloto Eric Marcon François Morneau Sandrine Pavoine Jean-Christophe Roggy 《Annals of Forest Science》2010,67(3):303-303