scholarly journals REPRODUCTIVE SYSTEM AND POLLEN FLOW IN PROGENIES OF Qualea grandiflora Mart., A TYPICAL SPECIES OF THE BRAZILIAN CERRADO

2015 ◽  
Vol 39 (2) ◽  
pp. 337-344 ◽  
Author(s):  
Lia Maris Orth Ritter Antiqueira ◽  
Paulo Yoshio Kageyama
Keyword(s):  
Reproductive System ◽  
Random Mating ◽  
Point Of View ◽  
Dispersion Pattern ◽  
Brazilian Cerrado ◽  
Fixation Rate ◽  
Pollen Dispersion ◽  
Typical Species ◽  
Environmental Recovery ◽  
Self Fertilization

This study analyzed the reproductive system and the pollen dispersion pattern of Qualea grandiflora progenies. This is a typical species from the Brazilian Cerrado about which there are not too many studies from the genetics point of view. The study was conducted in an area of 2.2 hectares located in the Conservation Unit managed by the Forest Institute of the state of São Paulo, Brazil (Assis State Forest). Total genomic DNA of 300 seeds from 25 plants (12 seeds from each plant) was extracted and amplified using specific primers to obtain microsatellite markers. Results showed that selfing is frequent among adults and progenies, and the species reproduces by outcrossing between related and unrelated individuals (0.913). The single-locus outcrossing rate was 0.632, which indicates that mating between unrelated individuals is more frequent than between related plants. The selfing rate was low (0.087), that is, the species is allogamous and self-fertilization is reduced. About 35% of the plants in the progenies were full-sibs, and about 57%, half-sibs. Besides, about 8% of the progenies were selfing siblings. The genetic differentiation coefficient within progenies was 0.139, whereas the fixation rate was about 27%. The estimate of the effective size revealed that the genetic representativeness of descent was lower than expected in random mating progenies: The analyzed samples corresponded to only 13.2 individuals of an ideal panmictic population. In environmental recovery programs, seeds, preferably from different fruits, should be collected from 95 trees to preserve the genetic diversity of the species.

Styrax camporum, a typical species of the Brazilian cerrado, attenuates DNA damage, preneoplastic lesions and oxidative stress in experimental rat colon carcinogenesis

2021 ◽  
pp. 1-11
Author(s):  
Pollyanna Francielli De Oliveira ◽  
Luis Fernando Leandro ◽  
Ricardo Andrade Furtado ◽  
Natália Helen Ferreira ◽  
Patrícia Mendonça Pauletti ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Colon Carcinogenesis ◽  
Rat Colon ◽  
Brazilian Cerrado ◽  
Preneoplastic Lesions ◽  
Typical Species ◽  
And Oxidative Stress

scholarly journals The distribution of mutational effects on fitness in Caenorhabditis elegans inferred from standing genetic variation

2020 ◽  
Author(s):  
Kimberly J. Gilbert ◽  
Stefan Zdraljevic ◽  
Daniel E. Cook ◽  
Asher D. Cutter ◽  
Erik C. Andersen ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Caenorhabditis Elegans ◽  
Population Size ◽  
Genomic Structure ◽  
Random Mating ◽  
Population Substructure ◽  
C Elegans ◽  
Fitness Effects ◽  
Self Fertilization ◽  
New Mutations

ABSTRACTThe distribution of fitness effects for new mutations is one of the most theoretically important but difficult to estimate properties in population genetics. A crucial challenge to inferring the distribution of fitness effects (DFE) from natural genetic variation is the sensitivity of the site frequency spectrum to factors like population size change, population substructure, and non-random mating. Although inference methods aim to control for population size changes, the influence of non-random mating remains incompletely understood, despite being a common feature of many species. We report the distribution of fitness effects estimated from 326 genomes of Caenorhabditis elegans, a nematode roundworm with a high rate of self-fertilization. We evaluate the robustness of DFE inferences using simulated data that mimics the genomic structure and reproductive life history of C. elegans. Our observations demonstrate how the combined influence of self-fertilization, genome structure, and natural selection can conspire to compromise estimates of the DFE from extant polymorphisms. These factors together tend to bias inferences towards weakly deleterious mutations, making it challenging to have full confidence in the inferred DFE of new mutations as deduced from standing genetic variation in species like C. elegans. Improved methods for inferring the distribution of fitness effects are needed to appropriately handle strong linked selection and selfing. These results highlight the importance of understanding the combined effects of processes that can bias our interpretations of evolution in natural populations.

scholarly journals Investigation of Effective Factors on Calving Interval of Cows in Faryab Province

2021 ◽  
Vol 8 (2) ◽  
pp. 63-68
Author(s):  
Saifullah Saadat
Keyword(s):  
Dairy Cows ◽  
Reproductive System ◽  
Research Area ◽  
General Purpose ◽  
Point Of View ◽  
Economic Losses ◽  
Meat Production ◽  
Calving Interval ◽  
Effective Factors ◽  
Inadequate Nutrition

This research was conducted to investigate the effects of factors (Identification of female cows, timely insemination of identified begging cows, diseases related to the reproductive system and nutrition) on the calving interval of dairy cows in Faryab province. Whereas, the long interval between two deliveries due to the identification of female cows, the increase in the number of inseminations (due to the failure of previous insemination), poor nutritional management and genital infections cause a long interval between calving to retrieval of cows. In that case, it will significantly reduce milk production and livestock income, because calving interval is one of the most important indicators of reproduction and economic characteristics of dairy cows, which is the interval between two calving intervals. Under the best of circumstances, one cow gives birth to only one calf per year. Calves born are important from both the point of view of meat production and replacement of old and low-producing cows. Identifying the effective factors and their effects on the calving interval between dairy cows and preventing the economic losses of dairy farmers due to increasing the calving interval between calves are the general purpose of this research. In this research, Andkhoy, Qurghan and other Faryab districts were randomly selected from three villages in each district and 10 owners from each village, which included three districts, 9 villages and nine livestock, respectively. The results of the present research showed that the interval between calving of dairy cows in the research area was due to the untimely identification of female cows by herders, increasing the number of inseminations due to the failure of previous inseminations of diseases related to the reproductive system and inadequate nutrition. The average time after delivery for the uterus to return to its previous state was 465 days.

Mating system and genetic polymorphism in populations of Secale cereale and S. vavilovii

1984 ◽  
Vol 26 (3) ◽  
pp. 308-317 ◽  
Author(s):  
M. Pérez De La Vega ◽  
R. W. Allard
Keyword(s):  
Mating System ◽  
Secale Cereale ◽  
Random Mating ◽  
Genetic Studies ◽  
Banding Patterns ◽  
Enzyme Systems ◽  
Incompatibility System ◽  
Secale Cereale L ◽  
Isozyme Polymorphism ◽  
Self Fertilization

Electrophoretic banding patterns were determined for nine enzyme systems (IPO, PGM, PGI, LAP, GOT, EST, PHOS, MDH, CPX) in four populations of Secale cereale L. from widely different geographical areas, and in one population of S. vavilovii Grossh. Secale cereale was found to be extensively variable and S. vavilovii invariant for these enzyme systems. Formal genetic studies of nine polymorphic banding zones in S. cereale revealed that each zone was under single locus control. Mating system studies based on these loci indicated that 8% of self-fertilization occurred under field conditions in a population of S. cereale, a species with a highly developed self-incompatibility system. Each population was characterized by fewer heterozygotes than expected in random mating populations. Genotypic and allelic frequencies were nearly identical in four populations of S. cereale, despite their diverse origins and different cytological characteristics.Key words: mating system, Secale, rye, isozyme polymorphism.

scholarly journals NEW PROPERTIES OF THE TWO-LOCUS PARTIAL SELFING MODEL WITH SELECTION

Genetics ◽  
1979 ◽  
Vol 93 (1) ◽  
pp. 217-236
Author(s):  
L R Holden
Keyword(s):  
Random Mating ◽  
Analytic Solutions ◽  
Selection Model ◽  
Equilibrium Potential ◽  
Gametic Disequilibrium ◽  
Self Fertilization ◽  
Mean Fitness ◽  
Mixed Selfing

ABSTRACT Analytic solutions are obtained for the equilibria of a simple two-locus, heterotic selection model with mixed selfing and random outcrossing. T W O general phenomena are possible, depending upon the viabilities and the degree of selfing: (1) Negative disequilibrium potential, under which only gametic disequilibrium is possible; and (2) positive disequilibrium potential, which can result in permanent gametic disequilibrium provided that linkage is sufficiently tight. Under random mating (s = O), these two situations correspond to negative and positive additive epistasis, respectively. With partial self-fertilization, however, this is no longer true, and a more appropriate measure of gametc dis-equilibrium potential, ∆ (s), is introduced. A numerically aided examination of the model results in the discovery of two new properties of partial selfing with selection: (1) With negative disequilibrium potential (∆(s) < 0), the equilibrium mean fitness increases with increasing recombination. With positive disequilibrium potential (∆(s) > 0), the opposite is true. (2) Gametic disequilibrium can increase or decrease as the degree of selfing is increased. Therefore, it is apparent that partial selfing and linkage are not analogous as regards the maintenance of disequilibrium.

Strategies for the environmental recovery of abandoned mining areas

2021 ◽  
Author(s):  
Manuel Hernández-Córdoba ◽  
Maria Jose Martinez-Sánchez ◽  
Salvadora Martinez López ◽  
Lucia Belén Martinez-Martinez ◽  
Carmen Hernández-Pérez ◽  
...  
Keyword(s):  
Natural Attenuation ◽  
Aerial Part ◽  
Environmental Problems ◽  
Point Of View ◽  
Mining Areas ◽  
Geological Processes ◽  
Environmental Recovery ◽  
Low Concentrations ◽  
Clear Vision ◽  
Particulate Dispersion

<p>Abandoned mining areas are a clear example of the failure of the different administrations to solve the environmental problems they pose, due to the lack of unified legislation and management and the activity of geological processes. It is therefore important to have a clear vision of the environmental problems that occur and the possible actions to solve them.</p><p>The Sierra Minera (Cartagena, SE Spain) presents situations of risk of soil contamination that coincide with those areas with the highest content of soluble and/or bioavailable PTEs (potentially toxic elements) for the health of people and ecosystems, especially in those sites of concentration of polluting sources (flotation mud pools and heterogeneous dumps), with a very fine texture. These areas present numerous points with an urgent need for risk management due to the possible mobilization in different environmental conditions of arsenic and heavy metals, with a control of both soluble and particulate dispersion. Special interest presents arsenic mobilisation in an acidic environment together with reducing situations and the presence of organic matter (waterlogged marshes).</p><p>The recovery technologies to be applied in the Sierra Minera require a great diversity of techniques, depending on the uses of the land. In the contamination foci it is necessary to carry out actions with containment, stabilisation and solidification technologies in situ. Phytoremediation techniques, given the high content of PTEs present, may not all be appropriate in the different situations. Phytoextraction should only be applied in areas with low concentrations of PTEs, and by plants that do not transfer to their aerial part, to avoid the risk of ingestion by animals. Phytostabilisation will be important in combined techniques, in order to ensure that contaminants are not transferred to the environment, and by non-accumulating plants in the aerial part. Wetlands can be a complementary solution to the projects developed at the heading of wadis, providing a double purpose, natural attenuation of contamination and lamination of turbulence and floods.</p><p>A generic overview is given of the most important regeneration approaches from a geochemical point of view, without going into structural solutions, selecting those technologies that are most suitable to the environment in which they are located, trying to imitate natural attenuation processes and using eco-efficient and sustainable materials.</p>

Structure and development of the reproductive system of some species of Nematocera (order Diptera: suborder Nematocera)

1950 ◽  
Vol 234 (614) ◽  
pp. 339-396 ◽  
Keyword(s):  
Reproductive System ◽  
Reproductive Systems ◽  
Male And Female ◽  
Typical Species ◽  
Accessory Glands ◽  
Efferent Ducts ◽  
The Common

The male and female reproductive systems in three typical species of Nematocera, order Diptera, representing the families of Chironomidae, Anisopidae and Mycetophilidae, have been studied and their development followed through the larva and pupa. A description has been given of the parts in each case in the imaginal fly, and as seen in development and a nomenclature of parts adopted in accordance with the homologies ascertained. In each case the basal plan is similar, but there is wide departure in the functional adaptations and form of the parts, so that without a study of the development the nature of some of the parts shown to be developmentally homologous would not be apparent. Briefly the reproductive system comprises in both sexes: ( a ) A primary reproductive system consisting of a pair of gonads in the sixth segment with mesodermal strands forming the primative mesodermal oviducts and vasa efferentia and linking the gonads with the ectodermal efferent ducts. ( b ) A secondary reproductive system of ectodermal origin which forms the greater part of both male and female efferent systems and which originates from hypodermal proliferative rudiments on the hypopygial segments and which may in various degrees replace by overgrowth the mesodermal ducts. ( c ) Appendicular parts forming in the male clasping organs (gonocoxites) and gonapophysial organs (paramere lobes) and also intersegmental inflexions and sclerotizations such as the atrium and vaginal apodeme in the female and the theca, penis sheath and, when present, an eversible sac or endotheca in the male. In the male recognizable homologous processes are the consecutive invaginations of the twin ejaculatory ducts and the median invagination of the penis tube, which later may be followed by a third intersegmental inflexion, that of the genital pouch excavating the penis and in Anisopus forming in its walls sclerotizations of the pompetta and piston apodeme. In the female are three recognizable invaginations, that taking origin from the eighth sternite rudiments, which conjointly by their peripodial cavity form the vagina with the spermathecal and later the common oviduct invaginations, and that from the conjoined hypodermal buds on the ninth sternite forming the caecus (the accessory glands).

scholarly journals Development of microsatellite markers forQualea grandiflora(Vochysiaceae), a typical species of the Brazilian cerrado

2012 ◽  
Vol 99 (3) ◽  
pp. e97-e98 ◽  
Author(s):  
Lia Maris Orth Ritter ◽  
Miklos Maximiliano Bajay ◽  
Mariza Monteiro ◽  
Renata G. V. C. Souza ◽  
Maria Andréia Moreno ◽  
...  
Keyword(s):  
Microsatellite Markers ◽  
Brazilian Cerrado ◽  
Typical Species

scholarly journals Comparative effects of pollen and seed migration on the cytonuclear structure of plant populations. I. Maternal cytoplasmic inheritance.

Genetics ◽  
1991 ◽  
Vol 128 (3) ◽  
pp. 639-654
Author(s):  
M A Asmussen ◽  
A Schnabel
Keyword(s):  
De Novo ◽  
Life Stage ◽  
Random Mating ◽  
Cytoplasmic Inheritance ◽  
Island Population ◽  
Mixed Mating ◽  
Seed Migration ◽  
Self Fertilization ◽  
Basic Behavior ◽  
Special Case

Abstract We explicitly solve and analyze a series of deterministic continent-island models to delimit the effects of pollen and seed migration on cytonuclear frequencies and disequilibria in random-mating, mixed-mating and self-fertilized populations. Given the critical assumption of maternal cytoplasmic inheritance, five major findings are (i) nonzero cytonuclear disequilibria will be maintained in the island population if and only if at least some migration occurs each generation through seeds with nonrandom cytonuclear associations; (ii) immigrant seeds with no cytonuclear disequilibria can strongly affect the genetic structure of the island population by generating significant and long-lasting transient associations; (iii) with all else being equal, substantially greater admixture disequilibria are generally found with higher rates of seed migration into, or higher levels of self-fertilization within, the island population (with the possible exception of the heterozygote disequilibrium); (iv) pollen migration can either enhance or reduce the cytonuclear disequilibria caused by seed migration, or that due to mixed-mating in the absence of seed migration, but the effect is usually small and appears primarily to make a noticeable difference in predominantly outcrossing populations; and (v) pollen migration alone cannot generate even transient disequilibria de novo in populations with completely random associations. This same basic behavior is exhibited as long as there is some random outcrossing in the island population. Self-fertilized populations represent a special case, however, in that they are necessarily closed to pollen migration, and nonzero disequilibria can be maintained even in the absence of seed migration. All of these general results hold whether the population is censused as adults or as seeds, but the ability to detect nonrandom cytonuclear associations can depend strongly on the life stage censused in populations with a significant level of random outcrossing. We suggest how these models might be used for the estimation of seed and pollen migration.

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