scholarly journals Evolution under domestication of correlated characters in populations of Stenocereus stellatus (Pfeiff.) Riccob., under different forms of management in central Mexico: genetic diversity, damage, and defense mechanisms

2021 ◽  
Author(s):  
Verónica Patiño-López ◽  
David Bravo-Avilez ◽  
Carlos F. Vargas-Mendoza ◽  
José Blancas ◽  
Beatriz Rendón-Aguilar
Keyword(s):  
Genetic Diversity ◽  
Defense Mechanisms ◽  
Central Mexico ◽  
Damage Level ◽  
Stenocereus Stellatus ◽  
Domestication Process ◽  
Cultivated Populations ◽  
Correlated Characters ◽  
Human Selection

AbstractAcross the process of domestication, human selection produces changes in target attributes as well as changes that are not necessarily desired by humans due to pleiotropic or linked genes. In this paper we addressed, correlated changes between genetic diversity, damage level, defense mechanisms (resistance and tolerance), and fitness due to the domestication process of Stenocereus pruinosus (Otto ex Pfeiff.) Buxbaum and Stenocereus stellatus (Pfeiff.) Riccobono, an endemic columnar cactus of south-central Mexico. One hundred eighty individuals of S. stellatus from wild, in situ managed, and cultivated populations of Valle de Tehuacán and Mixteca Baja, Puebla, were sampled, and attributes including damage level, defense mechanisms and fitness (number of fruits) were measured. The DNA of 176 individuals was extracted to amplify and analyze five microsatellites in order to estimate genetic diversity and structure. As expected, cultivated populations showed a significantly higher damage level, as well as lower resistance and genetic diversity. Depending on the form of management, correlations between genetic diversity and the rest of the attributes exhibited different patterns. In wild populations, genetic diversity was positively correlated with damage and negatively with resistance; in situ managed populations exhibited the opposite pattern, and in cultivated populations, no correlations were found between these attributes. We propose a hypothetic model of human selection to explain the variation in these correlations. No differences in genetic diversity and tolerance were detected between regions; however, the populations of Valle de Tehuacán exhibited more damage and more resistance. In both regions, populations showed a positive correlation between fitness and resistance and a negative correlation between damage and resistance, suggesting the existence of a defense mechanism to ensure fitness. Also, non-regional differentiation suggests an eventual gene flow due to pollinators, human movement of branches, or a common ancestry before the domestication process.

Indirect estimates reveal the potential of transgene flow in the crop–wild–weed Sorghum bicolor complex in its centre of origin, Ethiopia

2016 ◽  
Vol 15 (6) ◽  
pp. 496-505
Author(s):  
Asfaw Adugna ◽  
Endashaw Bekele
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Phenotypic Traits ◽  
Wild Populations ◽  
Centre Of Origin ◽  
Transgene Flow ◽  
Potential Risks ◽  
Cultivated Populations ◽  
Simple Sequence

AbstractA study was carried out between 2008 and 2011 to investigate the potential risks of gene flow and its consequences in the crop–wild–weed S. bicolor complex in Ethiopia to aid efforts to conserve genetic diversity. Morphological measurements and genomic DNA samples were taken in situ from 30 wild and eight cultivated populations representing a total of 760 samples from five regions. Genetic diversity, gene flow, population structure and outcrossing rates of wild populations were computed using phenotypic measurements and/or polymorphic simple sequence repeat (SSR) markers. Moreover, morphological analyses of fitness of crop–wild hybrids were studied. High diversity was observed among the wild/weedy sorghum populations for phenotypic traits and SSRs. SSR diversity was high in both wild and cultivated populations, but the magnitude was greater in the former. Gene flow between the wild and the cultivated sorghum was observed to be higher than that within either pool. Wild sorghums exhibited variation in the multilocus outcrossing rate (range = 0.31–0.65) and fitness was not compromised in most wild × crop hybrids. The study indicated that crop-to-wild gene flow is possible in Ethiopia. Thus, genes from transgenic sorghum are expected to enter into the wild and non-transgenic cultivated populations and may spread and persist, if transgenic sorghum is deployed in Ethiopia and in other countries of Africa, which may pose risk of introduction of unwanted effects, which in turn may lead to loss of genetic diversity.

scholarly journals Evolutionary dynamics of Cucurbita argyrosperma from the Mesoamerican domestication center using SSR molecular markers

2018 ◽  
Vol 53 (3) ◽  
pp. 287-297
Author(s):  
Daniela Priori ◽  
Daniel Zizumbo Villarreal ◽  
Víctor Manuel de Jesús Canché Ek ◽  
Verónica Limones-Briones ◽  
Rosa Lía Barbieri
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Gene Flow ◽  
Evolutionary Dynamics ◽  
High Gene Flow ◽  
Ssr Primers ◽  
Young Leaves ◽  
High Gene ◽  
Cultivated Populations ◽  
Human Selection

Abstract: The objective of this work was to evaluate the evolutionary dynamics of the wild-weedy-domestic gene pool of Cucurbita argyrosperma squash by estimating the levels of genetic diversity and gene flow in the putative area of its domestication. Nine populations were collected, and DNA was extracted from young leaves harvested separately from approximately 20 individuals in each population. The DNA fragments were amplified with eight pairs of SSR primers and separated by electrophoresis in 5% denaturing polyacrylamide gels. Genetic diversity and the amount of gene flow were estimated in the populations, and Bayesian grouping was used to determine the levels of gene infiltration and probability of ancestry. The ethnobotanical exploration indicated that the evolutionary dynamics in the area occurred under five different ecological scenarios. Eighty-seven alleles with 75% to 100% polymorphic loci were identified. The greater genetic diversity in the weedy-domestic populations may have been the product of recombination due to the high gene flow between these populations promoted by pollinators and human selection. There is high gene flow between the wild and cultivated populations of C. argyrosperma in its domestication centre, highlighting the importance of conserving and maintaining these genetic resources.

scholarly journals La domesticación de Stenocereus stellatus (Pfeiffer) Riccobono (Cactaceae)

2017 ◽  
pp. 129
Author(s):  
Alejandro Casas ◽  
Alfonso Valiente-Banuet ◽  
Javier Caballero
Keyword(s):  
Natural Selection ◽  
Artificial Selection ◽  
Reproductive System ◽  
Home Gardens ◽  
Morphological Divergence ◽  
Wild Populations ◽  
Silvicultural Management ◽  
Stenocereus Stellatus ◽  
Cultivated Populations

This study aimed at analyzing processes of domestication by silvicultural forms of management. The effects of artificial selection on morphology and reproductive biology of Stenocereus stellatus are analyzed in wild; wild-managed in situ (silvicultural management) and cultivated populations from the Tehuacan Valley and La Mixteca Baja. People select the phenotypes of this columnar cactus species with relatively larger and sweeter fruits with thinner peel and fewer spines, favoring their numbers in wild populations managed in situ as well as in home gardens. Favorable phenotypes prevail in wild populations managed in situ, indicating that artificial selection has had significant effects under this form of management. These phenotypes are especially abundant in home gardens, which suggests that artificial selection is even stronger under cultivation. Favorable phenotypes are scarce or absent in non-manipulated wild populations. Such morphological divergence is maintained despite the reproductive system of S. stellatus, is self-incompatible in all populations, and even when there were not found spatial and temporal barriers for pollen flow between wild and cultivated populations. Abundance of favorable phenotypes in areas managed by people may be explained by action of artificial selection, while absence of some domesticated phenotypes in wild populations seems to be due to pollen incompatibility between some cultivated phenotypes and wild populations, but it could also be due to pressures of natural selection against cultivated phenotypes.

scholarly journals Validating South Sudan as a Center of Origin for Coffea arabica: Implications for Conservation and Coffee Crop Improvement

2021 ◽  
Vol 5 ◽  
Author(s):  
Sarada Krishnan ◽  
Solene Pruvot-Woehl ◽  
Aaron P. Davis ◽  
Tim Schilling ◽  
Justin Moat ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Crop Improvement ◽  
South Sudan ◽  
Ex Situ ◽  
Breeding Programs ◽  
Center Of Origin ◽  
Arabica Coffee ◽  
Low Genetic Diversity ◽  
Cultivated Populations

Cultivated Arabica coffee outside Ethiopia is plagued by low genetic diversity, compromising disease resistance, climate resiliency and sensory potential. Access to the wider genetic diversity of this species may circumvent some of these problems. In addition to Ethiopia, South Sudan has been postulated as a center of origin for Arabica coffee, but this has never been genetically confirmed. We used simple sequence repeat (SSR) markers to assess the genetic diversity of wild and cultivated populations of Arabica coffee from the Boma Plateau in South Sudan, against farmed accessions (of wild origin) from Ethiopia, Yemen, and global cultivars. Our results not only validate Boma Plateau as part of the natural distribution and as a center of origin for Arabica coffee but also indicate that wild populations in South Sudan are genetically distinct from Ethiopian Arabica. This newly identified genetic diversity within Arabica could have the potential for crop improvement through selection and use in breeding programs. Observations and analyses show that the extent and health of the wild population of Arabica in South Sudan have declined. Urgent action should be taken to conserve (in situ and ex situ) the unique, remaining genetic diversity of wild Arabica populations in South Sudan.

Assessment of genetic variability amongst cultivated populations of Khasi mandarin (Citrus reticulata Blanco) detected by ISSR

2021 ◽  
pp. 1-11
Author(s):  
Karishma Kashyap ◽  
Rasika M. Bhagwat ◽  
Sofia Banu
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Inter Simple Sequence Repeat ◽  
Northeast India ◽  
Issr Markers ◽  
Citrus Reticulata ◽  
Brahmaputra Valley ◽  
Indian Food ◽  
Cultivated Populations ◽  
High Level

Abstract Khasi mandarin (Citrus reticulata Blanco) is a commercial mandarin variety grown in northeast India and one of the 175 Indian food items included in the global first food atlas. The cultivated plantations of Khasi mandarin grown prominently in the lower Brahmaputra valley of Assam, northeast India, have been genetically eroded. The lack in the efforts for conservation of genetic variability in this mandarin variety prompted diversity analysis of Khasi mandarin germplasm across the region. Thus, the study aimed to investigate genetic diversity and partitioning of the genetic variations within and among 92 populations of Khasi mandarin collected from 10 cultivated sites in Kamrup and Kamrup (M) districts of Assam, India, using Inter-Simple Sequence Repeat (ISSR) markers. The amplification of genomic DNA with 17 ISSR primers yielded 216 scorable DNA amplicons of which 177 (81.94%) were polymorphic. The average polymorphism information content was 0.39 per primer. The total genetic diversity (HT = 0.28 ± 0.03) was close to the diversity within the population (HS = 0.20 ± 0.01). A high mean coefficient of gene differentiation (GST = 0.29) reflected a high level of gene flow (Nm = 1.22), indicating high genetic differentiation among the populations. Analysis of Molecular Variance (AMOVA) showed 78% of intra-population differentiation, 21% among the population and 1% among the districts. The obtained results indicate the existence of a high level of genetic diversity in the cultivated Khasi mandarin populations, indicating the need for preservation of each existing population to revive the dying out orchards in northeast India.

scholarly journals Unveiling a unique genetic diversity of cultivated Coffea arabica L. in its main domestication center: Yemen

2021 ◽  
Author(s):  
C. Montagnon ◽  
A. Mahyoub ◽  
W. Solano ◽  
F. Sheibani
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Coffea Arabica ◽  
Genetic Improvement ◽  
The World ◽  
Genetic Clusters ◽  
Domestication Process ◽  
Almost All ◽  
Coffea Arabica L ◽  
Cup Quality

AbstractWhilst it is established that almost all cultivated coffee (Coffea arabica L.) varieties originated in Yemen after some coffee seeds were introduced into Yemen from neighboring Ethiopia, the actual coffee genetic diversity in Yemen and its significance to the coffee world had never been explored. We observed five genetic clusters. The first cluster, which we named the Ethiopian-Only (EO) cluster, was made up exclusively of the Ethiopian accessions. This cluster was clearly separated from the Yemen and cultivated varieties clusters, hence confirming the genetic distance between wild Ethiopian accessions and coffee cultivated varieties around the world. The second cluster, which we named the SL-17 cluster, was a small cluster of cultivated worldwide varieties and included no Yemen samples. Two other clusters were made up of worldwide varieties and Yemen samples. We named these the Yemen Typica-Bourbon cluster and the Yemen SL-34 cluster. Finally, we observed one cluster that was unique to Yemen and was not related to any known cultivated varieties and not even to any known Ethiopian accession: we name this cluster the New-Yemen cluster. We discuss the consequences of these findings and their potential to pave the way for further comprehensive genetic improvement projects for the identification of major resilience/adaptation and cup quality genes that have been shaped through the domestication process of C. arabica.

Genetic diversity of the extremely rare Habenaria dentata and the rare Habenaria linearifolia (Orchidaceae) in South Korea: implications for population history and conservation

2018 ◽  
Vol 151 (1) ◽  
pp. 48-60
Author(s):  
Mi Yoon Chung ◽  
Hoa Thi Quynh Le ◽  
Sungwon Son ◽  
Huai Zhen Tian ◽  
Myong Gi Chung
Keyword(s):  
Genetic Diversity ◽  
Southern China ◽  
Geographic Location ◽  
Population History ◽  
Population Variation ◽  
Conservation Strategies ◽  
Ancestral Population ◽  
Allozyme Diversity ◽  
Glacial Origin

Background and aims – Since historical events often leave an indelible mark on levels of genetic diversity of plant populations, one may indirectly infer their evolutionary history with the help of current patterns of genetic diversity. The terrestrial orchid Habenaria dentata, an element of warm-temperate/subtropical vegetation, reaches its northernmost limits in the Korean Peninsula, and thus it is extremely rare there. As H. dentata was absent from the Peninsula during the Last Glacial Maximum (LGM), it is likely to be of post-glacial origin having arrived from either a single refugium or multiple refugia. However, its rare, temperate/boreal congener H. linearifolia might have persisted in situ in either macrorefugia or microrefugia on the Peninsula during the LGM.Methods – To test which hypothesis is most appropriate for each species, we investigated levels of allozyme-based (17 loci) genetic diversity and population genetic structure in the two only known populations of H. dentata and in 12 populations of H. linearifolia.Key results – No allozyme diversity was found in H. dentata (He = 0.000), whereas H. linearifolia exhibited low within-population variation (He = 0.060) and high among-population differentiation (FST = 0.237). We found little association between populations in relation to their geographic location; several populations presented individuals belonging to different clusters.Conclusions – Our results suggest that H. dentata likely originated from a single ancestral population (perhaps from southern Japan or southern China) through post-glacial dispersal, whereas H. linearifolia probably survived the LGM in situ in microrefugia situated at low to mid-elevated regions. We further suggest that separate conservation strategies for each species should be employed, given that the two taxa have different ecological and demographic traits and harbour different levels of genetic diversity.

scholarly journals Ophthalmic Drug Dosage Forms: Characterisation and Research Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Przemysław Baranowski ◽  
Bożena Karolewicz ◽  
Maciej Gajda ◽  
Janusz Pluta
Keyword(s):  
Defense Mechanisms ◽  
Drug Application ◽  
Drug Dosage ◽  
Eye Drops ◽  
Eye Tissues ◽  
Ophthalmic Drug ◽  
Application Frequency

This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments,in situgels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to defense mechanisms of the human eye, extending contact time of drug with the cornea, increasing the penetration through the complex anatomical structure of the eye, and providing controlled release of drugs into the eye tissues, which allows reducing the drug application frequency. The rest of the paper describes recommendedin vitroandin vivostudies to be performed for various ophthalmic drugs forms in order to assess whether the form is acceptable from the perspective of desired properties and patient’s compliance.

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