Cyanogenic polymorphism as an indicator of genetic diversity in the rarespecies Eucalyptus yarraensis (Myrtaceae)

2002 ◽  
Vol 29 (12) ◽  
pp. 1445 ◽  
Author(s):  
Jason Q. D. Goodger ◽  
Ian E. Woodrow
Keyword(s):  
Genetic Diversity ◽  
Effective Means ◽  
Natural Populations ◽  
Population Variation ◽  
Conservation Strategy ◽  
Narrow Sense Heritability ◽  
Specialist Herbivores ◽  
Cyanogenic Plants ◽  
Physical And Chemical ◽  
First Time

The rare Australian tree Eucalyptus yarraensis Maiden & Cambage is cyanogenic, a quantitative trait potentially indicative of genetic diversity. Cyanogenic plants are capable of releasing cyanide from endogenous cyanide-containing compounds. Cyanide is toxic or deterrent to generalist or non-adapted specialist herbivores. Consequently, cyanogenic plants are afforded an effective means of chemical defense. In this paper we characterize quantitative variation in cyanogenic capability, known as cyanogenic polymorphism, in E. yarraensis for the first time. We show that the cyanogenic glucoside prunasin (R-mandelonitrile-β-D-glucoside) is the only cyanogenic compound in E. yarraensis foliage. We also show that two natural populations of E. yarraensis display extensive intra- and inter-population variation in foliar prunasin concentration. The high prunasin concentrations reported in this paper represent the highest yet recorded for mature eucalypt leaves. The cyanogenic variation could not be attributed to measured physical and chemical parameters, supporting the hypothesis that the variation is genetically based. A preliminary progeny trial also supports this hypothesis, with narrow sense heritability estimated at 1.17 from three half-sibling families. The variation in cyanogenic capability may be a useful tool in the development of a conservation strategy for the species.

Morpho-phenological diversity among Tunisian natural populations of Brachypodium hybridum

2014 ◽  
Vol 153 (6) ◽  
pp. 1006-1016 ◽  
Author(s):  
M. NEJI ◽  
F. GEUNA ◽  
W. TAAMALLI ◽  
Y. IBRAHIM ◽  
M. SMIDA ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Geographic Distribution ◽  
Phenotypic Diversity ◽  
Average Length ◽  
Natural Populations ◽  
Negative Relationship ◽  
Mantel Test ◽  
Population Variation ◽  
Long Distance ◽  
Temperate Cereal

SUMMARYBrachypodium hybridum belongs to the Poaceae grass subfamily. It has a close genetic relationship with temperate cereal crops, which means that it can be used as a model for temperate cereal and grass crops. In order to improve knowledge on the genetic diversity of this species, 145 lines of B. hybridum representative of nine populations and all the ecoregions of Tunisia were characterized on the basis of 18 morpho-phenologic features. The results show a considerable variation between populations and ecoregions in all traits studied. Variation was relatively higher for reproductive than vegetative traits. The majority of traits showed very low to high heritability with low border value for average length of spikelet (ALS) and an average value of 0·64. It is noticeable that high values of heritability were observed for most vegetative descriptors, with low values for reproductive ones. Differentiation between populations (QST) varied from 0·02 for ALS to 0·78 for average length of leaves with a mean value across traits of 0·4, which confirms the wide intra-population variation in Tunisian natural population of B. hybridum. Pairwise QST showed that the greatest differentiation among populations was registered between Ain Drahem and Jbel Zaghouan and the smallest between Haouria and Raoued. Overall, the Ain Draham population showed the largest differentiation from the rest of the populations. To infer the effect of geographic distribution of the species, a Mantel test was applied between observed pairwise differentiation and geographic distance between populations and between ecoregions: the results show a positive, but not significant, relationship. In addition a significant negative relationship was found between phenotypic diversity and altitude, indicating that genetic diversity decreased with increasing altitude. Taken together, the high levels of intra-population variation and the lack of correlation between genetic differentiation and geographic distribution suggest a potentially important rate of long-distance seed dispersal and confirm the role played by natural selection in the population structure of Tunisian natural populations of B. hybridum.

scholarly journals DNA profiling and assessment of genetic diversity of relict species Allium altaicum Pall. on the territory of Altai

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10674
Author(s):  
Oxana Khapilina ◽  
Olesya Raiser ◽  
Alevtina Danilova ◽  
Vladislav Shevtsov ◽  
Ainur Turzhanova ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Endangered Species ◽  
Biological Diversity ◽  
Vegetative Reproduction ◽  
Natural Populations ◽  
Mobile Genetic Elements ◽  
Ice Age ◽  
Conservation Strategy ◽  
Relict Species ◽  
Genetic Elements

Analysis of the genetic diversity of natural populations of threatened and endangered species of plants is a main aspect of conservation strategy. The endangered species Allium altaicum is a relict plant of the Ice Age and natural populations are located in extreme climatic conditions of Kazakstan’s Altai Mountains. Mobile genetic elements and other interspersed repeats are basic components of a eukaryote genome, which can activate under stress conditions and indirectly promote the survival of an organism against environmental stresses. Detections of chromosomal changes related to recombination processes of mobile genetic elements are performed by various PCR methods. These methods are based on interspersed repeat sequences and are an effective tool for research of biological diversity of plants and their variability. In our research, we used conservative sequences of tRNA primer binding sites (PBS) when initializing the retrotransposon replication as PCR primers to research the genetic diversity of 12 natural populations of A. altaicum found in various ecogeographic conditions of the Kazakhstani Altai. High efficiency of the PBS amplification method used was observed already at the intrapopulation level. Unique amplicons representative of a certain population were found at the intrapopulation level. Analysis of molecular dispersion revealed that the biodiversity of populations of mountainous and lowland A. altaicum is due to intrapopulation differences for climatic zones of habitation. This is likely conditional upon predominance of vegetative reproduction over seed reproduction in some populations. In the case of vegetative reproduction, somatic recombination related to the activity of mobile genetic elements are preserved in subsequent generations. This leads to an increase of intrapopulation genetic diversity. Thus, high genetic diversity was observed in populations such as A. altaicum located in the territory of the Kalbinskii Altai, whereas the minimum diversity was observed in the populations of the Leninororsk ecogeographic group. Distinctions between these populations were also identified depending on the areas of their distribution. Low-land and mid-mountain living environments are characterized by a great variety of shapes and plasticity. This work allowed us to obtain new genetic data on the structure of A. altaicum populations on the territory of the Kazakhstan Altai for the subsequent development of preservation and reproduction strategies for this relict species.

scholarly journals Regional genetic diversity in circadian period in Boechera stricta populations is high relative to the global range of diversity in Arabidopsis

2021 ◽  
Author(s):  
Robby McMinn ◽  
Matti Salmela ◽  
Cynthia Weinig
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Significant Proportion ◽  
Natural Populations ◽  
Elevational Gradient ◽  
Environmental Data ◽  
Population Variation ◽  
Circadian Period ◽  
In The Wild ◽  
Boechera Stricta

Circadian clocks manifest adaptations to predictable 24-h fluctuations in the exogenous environment, but it has yet to be determined why the endogenous circadian period length in the wild varies genetically around the hypothesized optimum of 24 h. We quantified genetic variation in circadian period in leaf movement in 30 natural populations of the Arabidopsis relative Boechera stricta sampled within only 1° of latitude but across an elevational gradient spanning 2460−3300 m in the Rocky Mountains. Measuring over 3800 plants from 473 maternal families (7−20 per population), we found genetic variation that was of similar magnitude among vs. within populations, with population means varying between 21.9−24.9 h and maternal family means within populations varying by up to ~6 h. After statistically factoring out spatial autocorrelation at the habitat extremes, we found that elevation explained a significant proportion of genetic variation in circadian period such that higher-elevation populations had shorter mean period lengths and less within-population variation. Environmental data indicate that these spatial trends could be related to steep regional climatic gradients in temperature, precipitation, and their intra-annual variability. Our findings provide evidence that spatially fine-grained environmental heterogeneity contributes to naturally occurring genetic diversity in circadian traits in wild populations.

Genetic structure and proposed conservation strategy for natural populations of Calycanthus chinensis Cheng et S.Y. Chang (Calycanthaceae)

2008 ◽  
Vol 88 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Chu-Chuan Fan ◽  
Nicola Pecchioni ◽  
Long-Qing Chen
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Genetic Distance ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
Natural Populations ◽  
Population Level ◽  
Conservation Strategy ◽  
Information Index

Calycanthus chinensis Cheng et S.Y. Chang, a tertiary relic species in China, is a shade-loving and deciduous bush withan elegant shape and beautiful flower of high ornamental value. It was widely planted in gardens and miniature scapes in China.The objective of this study was to characterize the genetic variation and structure in the three extant populations of the species, in order to provide useful information for a future conservation strategy. Twenty-two of 120 RAPD primers were selected and a total of 257 stable and clear DNA fragments were scored. Calycanthus chinensis showed a lower level of genetic diversity. At the population level, the percentage of polymorphic loci, Nei's gene diversity and Shannon’s information index were 40.9%, 0.1641 and 0.2386, respectively; while at the species level, the corresponding values were 59.1%, 0.2097 and 0.3123, respectively. The estimates of genetic differentiation based on Shannon’s information index (0.2360), Nei’s gene diversity (0.2175) and AMOVA (24.94%) were very similar, and significantly higher than the average genetic differentiation reported in outcrossed spermatophyte. So it suggested high genetic differentiation emerged among populations of C. chinensis. Genetic relationships among populations were assessed by Nei’s standard genetic distance, which suggested that the Tiantai population was genetically distinct from the other two populations. Moreover, the genetic distance was significantly correlated with geographical distance among populations (r = 0.997, t > t0.05). The gene flow (Nm) was 0.8994, indicating that gene exchange among populations was restricted. A conservation strategy was proposed based on the low gene flow and habitat deterioration, which are contributing to the endangered status of this species. Key words: Genetic diversity, endangered plant, population genetics, RAPD

Genetic diversity among natural populations of Agathis borneensis (Araucariaceae), a tropical rain forest conifer from Brunei Darussalam, Borneo, Southeast Asia

1992 ◽  
Vol 70 (10) ◽  
pp. 1945-1949 ◽  
Author(s):  
Keiko Kitamura ◽  
Mohamad Yusof Bin Abdul Rahman
Keyword(s):  
Genetic Diversity ◽  
Southeast Asia ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Natural Populations ◽  
Conservation Strategy ◽  
Restricted Gene Flow ◽  
Isozyme Electrophoresis ◽  
Brunei Darussalam ◽  
Population Component

Agathis is a genus of tropical conifers that occurs mainly in Southeast Asia. Because of its production of good softwood, many stands of Agathis have been harvested. We provide an estimate of genetic variation within and among populations of Agathis borneensis in Brunei Darussalam, Southeast Asia. Five populations were investigated using isozyme electrophoresis. We investigated a total of 17 putative loci, five of which were polymorphic. Estimated total heterozygosity was 0.122. Heterozygosity within populations was 0.106. The population structure did not deviate significantly from Hardy–Weinberg expectations. Nei's coefficient of gene differentiation indicated that the among-population component of genetic diversity represents 14% of the total population component. The low level of genetic diversity and the large diversity among populations were the opposite of that for conifers in the temperate zone, because of the small size of each population. The large diversity among populations indicated the restricted gene flow resulting from the asynchronous flowering of this species. The genetic distance indicated that A. borneensis in Brunei could be classified in two groups, with one isolated population considerably different from the others both genetically and ecologically. The conservation strategy is discussed from the viewpoint of genetic resources. Key words: Agathis borneensis, Araucariaceae, Brunei Darussalam, genetic diversity, isozyme, tropical rain forest.

scholarly journals Genetic variation in phenology and growth among and within Norway spruce populations from two altitudinal transects in Mid-Norway

Silva Fennica ◽  
2019 ◽  
Vol 53 (1) ◽  
Author(s):  
Tore Skrøppa ◽  
Arne Steffenrem
Keyword(s):  
High Altitude ◽  
Norway Spruce ◽  
Genetic Correlations ◽  
Natural Populations ◽  
Height Growth ◽  
Population Variation ◽  
Clinal Variation ◽  
Short Term ◽  
Narrow Sense Heritability

Progenies from open pollinated cones collected in natural populations of Norway spruce ( (L. Karst.)) distributed along two altitudinal transects in Mid-Norway were tested in the nursery, in short term tests and in long-term field trials. The populations showed clinal variation related to the mean annual temperatures of the populations, with the earliest bud flush and cessation of shoot elongation and lowest height at age nine years for the high altitude populations. Within population variation was considerable as the narrow sense heritability for these traits was 0.67, 0.31 and 0.09 in one transect and 0.55, 0.18 and 0.14 in the other transect, respectively. Lammas shoots occurred in the short term trials with large variation in frequency between years. There was significant family variation for this trait, but also interactions between populations and year. The variance within populations was considerably larger in the populations from low altitude compared to the high-altitude populations. Significant genetic correlations between height and phenology traits and damage scores indicate that families flushing early and ceasing growth late were taller. Taller families also had higher frequencies of damages. Selection of the top 20% families for height growth in short term tests at age nine years gave a simulated gain of 11% increased height growth at age 18 years in long term trials at altitudes similar to those of origin of the populations. The gain was negative when high altitude populations were selected based on testing in the lowland.Picea abies

Genetic variation and productivity of Populustrichocarpa and its hybrids. III. Structure and pattern of variation in a 3-year field test

1989 ◽  
Vol 19 (3) ◽  
pp. 372-377 ◽  
Author(s):  
D. L. Rogers ◽  
R. F. Stettler ◽  
P. E. Heilmann
Keyword(s):  
Block Design ◽  
Natural Populations ◽  
Large Degree ◽  
Population Variation ◽  
Black Cottonwood ◽  
Narrow Sense Heritability ◽  
Ongoing Work ◽  
Pattern Of Variation ◽  
Significant Block ◽  
River Valleys

Growth and morphology of 308 black cottonwood (Populustrichocarpa Torr & Gray) clones were studied at one plantation site in northwestern Washington. The material was derived from both open-pollinated seed and branch cuttings from 10 natural populations in major river valleys west of the Cascade Range, between central Oregon (latitude 44°44′) and southern British Columbia (latitude 49°05′). Most of the clones (258) were derived from open-pollinated seedlings, with approximately six from each of two to five selected parents per population. Fifty of the clones were ramets from five field-selected ortets per population. Each clone was represented by two ramets in each of two blocks in a randomized complete block design. Three-year height and diameter growth displayed the largest amount of variation at the clonal level, followed by lesser amounts at the family and population levels. A significant block × clone interaction, combined with some responses contrasting with earlier studies on a different site, suggests that the interaction of genotype with environment is important for this species. Weak clinal trends were observed, despite a large degree of within-population variation. Narrow-sense heritability estimates and their standard errors were 0.10 ± 0.08 and 0.13 ± 0.09 for 3rd-year height and diameter, respectively. Significant trait correlations were obtained between volume and branch characteristics. The implications of these results and their relationship to other ongoing work in black cottonwood are discussed.

scholarly journals Clonal Reproduction and Low Genetic Diversity in Northern Australian Santalum lanceolatum (Santalaceae) Populations Highlights the Need for Genetic Rescue of This Commercially Significant Species

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 741
Author(s):  
Aaron Brunton ◽  
David J. Lee ◽  
Gabriel Conroy ◽  
Steven Ogbourne
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
Life History Strategy ◽  
Conservation Strategy ◽  
Regional Differentiation ◽  
Genetic Rescue ◽  
Environmental Pressures ◽  
Northern Margin ◽  
Low Genetic Diversity ◽  
Wild Harvesting

Genetic diversity and the extent of clonality in a plant species can significantly influence its reproductive success. Whilst clonality can be an effective life-history strategy, in harsh environments it can lead to low levels of diversity and sexual reproductive failure. Santalum lanceolatum (Santalaceae) is a hemi-parasitic shrub endemic to the monsoonal dry tropics of northern Australia, which was harvested for its oil-rich heartwood from natural populations in Cape York, Australia. Despite wild harvesting ending over 70 years ago, populations in the region are currently declining. The aims of this study were to examine genetic variation, population genetic structure, inbreeding and clonality of six S. lanceolatum populations from this northern margin of the species range. Analyses of twelve microsatellite markers showed S. lanceolatum had low genetic diversity (AR = 2.776, HE = 0.409), evidence of regional differentiation (FST = 0.307–0.424) and negligible inbreeding levels (F = −0.052). Clonality investigations revealed 135 genets among 200 samples, suggesting that the clonal structure of S. lanceolatum may be limiting the potential for sexual reproduction and natural recruitment. We recommend a conservation strategy involving genetic rescue to prevent the further decline and potential local extinction from a variety of environmental pressures and human activities.

scholarly journals Genetic diversity of fragmented natural populations of Pyrenacantha volubilis Wight. in India

2021 ◽  
Author(s):  
Arjun Ramachandran ◽  
A. V. Santhoshkumar ◽  
Deepu Mathew ◽  
Manju Elizabeth ◽  
Jiji Joseph ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
Inter Simple Sequence Repeat ◽  
Morphological Data ◽  
Cancer Drug ◽  
Term Survival ◽  
Anti Cancer ◽  
Tree Algorithms ◽  
Nj Tree ◽  
First Time

Abstract Pyrenacantha volubilis Wight. is a dioecious liana occurring in small, clustered populations. The species had no documented use until the recent past, when it was identified to be a source of a highly traded anti-cancer drug – camptothecin. In the present study, we examine the genetic diversity of 12 fragmented natural populations of P. volubilis using morphological and molecular traits. Twelve polymorphic Inter Simple Sequence Repeat (ISSR) primers and 29 agromorphological traits were used to discriminate the populations using UPGMA and NJ tree algorithms respectively. The ISSR amplicon profile had 133 distinct bands. The maximum number of amplicons were produced by UBC 844 (20 bands) and the average polymorphism was 80.07 per cent. The dendrograms obtained based on molecular and agro-morphological data are in close congruence. The Thiruvananthapuram population stood apart in both the analyses as a discrete outgroup: perhaps a consequence of local adaptation. Substantial genetic diversity exists among populations. This could be tapped in domestication, which is the only way forward for the long-term survival of this species. We also report for the first time a standardized method for extraction of genomic DNA from the leaves of P. volubilis.

scholarly journals Combining modelling, field data and genetic variation to understand the post-reintroduction population genetics of the Marsh Fritillary butterfly (Euphydryas aurinia)

2021 ◽  
Author(s):  
Michelle L. Davis ◽  
Carl Barker ◽  
Ian Powell ◽  
Keith Porter ◽  
Paul Ashton
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Evolutionary Dynamics ◽  
Captive Breeding ◽  
Natural Populations ◽  
Population Variation ◽  
Past Century ◽  
Euphydryas Aurinia ◽  
Founder Populations ◽  
Marsh Fritillary

Abstract The Marsh Fritillary butterfly (Euphydryas aurinia) is a Eurasian species which has suffered significant reductions in occurrence and abundance over the past century, particularly across the western side of its range, due to agricultural intensification and habitat loss. This loss has been particularly severe in the UK with extensive localised extinctions. Following sympathetic management, reintroduction was undertaken at four Cumbria (northern UK) sites in 2007 with stock from a captive admixture population descended from Cumbrian and Scottish founders. Annual population monitoring of the reintroductions was undertaken. Nine years post-reintroduction, the level of population genetic variation was assessed using microsatellites. Variation in historical Cumbrian samples was determined using museum samples and Scottish samples from current populations were assayed to characterise natural population variation. Half of the Scottish sites also served as indicators of the alleles present in the founder populations. The genetic contribution of the founder populations allied to population size data allowed patterns of genetic variation to be modelled. Alleles from Cumbrian and Scottish founders are present in the reintroduced populations. The four sites have levels of variation akin to natural populations and exhibit differentiation as predicted by statistical modelling and comparable with natural populations. This suggests that reintroduction following captive breeding can produce self-sustaining populations with natural levels of genetic diversity. These populations appear to be undergoing the same evolutionary dynamics with bottlenecks and drift as natural populations. Implications for insect conservation Reintroduction of captive bred individuals is a viable strategy for producing populations with natural levels of genetic diversity and evolutionary dynamics. Hybridisation of populations on the brink of extinction with those thriving can preserve some of the genetic distinctiveness of the declining population.

Sign in / Sign up

Export Citation Format

Share Document