Conservation and management of genetic diversity: a domestic animal perspective

2001 ◽  
Vol 31 (4) ◽  
pp. 588-595 ◽  
Author(s):  
J SF Barker

In the context of domestic animal diversity, the term "breed" is conventionally used for all recognized populations. There are in total about 5000 breeds, a small proportion of which are in planned programs for genetic improvement, while about 30% are at risk of extinction. The primary focus is on the conservation of breeds, including management for better utilization (breeding programs) and conserving those at risk, with the aim of minimizing the loss of among breed diversity. The majority of the world's breeds are in the developing countries, with production environments that are low to medium input and high stress, and each may be expected to have adapted to its specific environment. Empirical evidence strongly supports the expectation that the genetic basis of population differentiation for fitness traits will be nonadditive, with different adaptive gene complexes evolved in each breed. Genetic improvement programs therefore should start with an adapted population, with selection then for production traits. As not all breeds can be conserved, priorities must be determined. Suggested criteria (breed divergence, risk of breed extinction, breed "merit," and within-breed variation) are presented and evaluated. Similar approaches may be appropriate for the conservation of genetic diversity of forest trees.

2003 ◽  
Vol 54 (5) ◽  
pp. 429 ◽  
Author(s):  
J. S. Croser ◽  
F. Ahmad ◽  
H. J. Clarke ◽  
K. H. M. Siddique

Efforts to improve the yield and quality of cultivated chickpea (Cicer arietinum L.) are constrained by a low level of intraspecific genetic diversity. Increased genetic diversity can be achieved via the hybridisation of the cultivated species with the unimproved 'wild' relatives from within the 43 species of the Cicer genus. To date, the 8 species sharing an annual growth habit and chromosome number with C. arietinum have been the primary focus of screening and introgression efforts. Screening of these species has uncovered morphological characteristics and resistance to a number of abiotic and biotic stresses that are of potential value to chickpea improvement programs. Detailed analysis of protein and DNA, karyotyping, and crossability studies have begun to elucidate the relationships between the annual Cicer species. In comparison, perennial species have received little attention due to difficulties in collection, propagation, and evaluation. This review discusses the progress towards an understanding of genetic relationships between the Cicer species, and the introgression of genes from the wild Cicer species into the cultivated species.


2021 ◽  
Vol 58 (2) ◽  
pp. 279-286
Author(s):  
Sandhani Saikia ◽  
Pratap Jyoti Handique ◽  
Mahendra K Modi

Genetic diversity is the source of novel allelic combinations that can be efficiently utilized in any crop improvement program. To facilitate future crop improvement programs in rice, a study was designed to identify the underlying genetic variations in the Sali rice germplasms of Assam using SSR markers. The 129 SSR markers that were used in the study amplified a total of 765 fragments with an average of 5.93 alleles per locus. The Shannon's Information Index was found to be in the range from 0.533 to 1.786. The Polymorphism Information Content (PIC) fell into the range from 0.304 to 0.691 with a mean value of 0.55. The overall FST value was found to be 0.519 that indicated the presence of genetic differentiation amongst the genotypes used in the study. The Sali population was divided into two clusters. The information obtained from the present study will facilitate the genetic improvement of Sali rice cultivars.


1994 ◽  
Vol 13 ◽  
pp. 3-10
Author(s):  
Ronan I. oftus

SUMMARYThe recently published World Watch List for Domestic Animal Diversity (WWL-DAD) provides the first comprehensive list of endangered livestock breeds worldwide (FAO/LTNEP 1993). This document will function as a global early warning system to help prevent the erosion of livestock genetic resources. Seven species are covered, namely ass, buffalo, cattle, goat, horse, pig and sheep. Within these species, breeds at risk are defined as critical (The Critical Breeds List) or endangered (The Endangered Breeds List) based on the number of breeding females. Although the statistics for these seven species are still incomplete at the time of going to press, over 390 breeds are already known to be at risk.


2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 169-170 ◽  
Author(s):  
Nayan Bhowmik ◽  
Kris A Ringwall ◽  
Carl R Dahlen ◽  
Kendall C Swanson ◽  
Lauren L Hulsman Hanna

Abstract Commercial beef cattle populations are rarely purebred. Understanding genetic diversity and population structure of crossbreds is important for future genetic improvement programs. Currently, an admixed beef cattle population comprised of British, Continental and Australian origin is being used for long-term research goals in understanding longevity, efficiency (reproductive and nutritional), and their interaction. This experiment aimed to assess the levels of genetic diversity and population structure among purebred (n = 6) and admixed (n = 3) sub-populations. A total of 727 animals were genotyped using the GeneSeek Genomic Profiler 150K. After quality checking, expected heterozygosity (HE) and polymorphism were calculated using 108,249 markers by sub-population. After LD-pruning, the remaining 19,316 SNP were used for pairwise fixation index (FST), analysis of molecular variance (AMOVA), and principle component analysis. The call rate for each sub-population ranged from 0.9866 ± 0.0351 to 0.9994 ± 0.0006. The lowest proportion (0.8527) of polymorphism was in the American Aberdeen (AA) and the highest proportion (1) was in the admixed populations. By sub-population, HE ranged from 0.3490 ± 0.1482 in AA to 0.3935 ± 0.1315 in Angus. The average nucleotide diversity over loci varied from 0.2976 ± 0.1444 in AA to 0.3872 ± 0.1879 in unknown parentage sub-population. The highest genetic differentiation was observed between AA and Continental breeds (Gelbvieh and Simmental) as FST estimates ranged from 0.1757 to 0.1789, respectively. Differences within individuals explained 98.15% of the total variance, whereas only -2.33% was due to differences among individuals within sub-populations. The first and second principal components (PC) explained 37.77% and 24.29% of the total variance, respectively. These PC show that admixed individuals clustered with animals of their primary breed. Therefore, this study suggests that clustering individuals according to their primary breed will assist in future genetic studies with this population and potentially future commercial genetic improvement programs.


2018 ◽  
Vol 51 ◽  
pp. 185-192
Author(s):  
S. Kruhlyk ◽  
V. Dzitsiuk ◽  
V. Spyrydonov

Genetic variability of domestic dogs is a source for effective process of breed formation and creating unique gene complexes. In the world, for preservation of genetic resources of dogs, there are dog training associations which have great confidence: American Club Dog Breeders (AKC), the British Kennel Club (KC) and the Federation Cynologique Internationale (FCI), aimed at protecting breeding dogs, standards creation, registration of a breed, and issuance of accurate pedigrees. Evaluation of the genetic diversity of dog breeds is able to significantly complement and improve their breeding programs. Since breeds of dog differ in morphological and economic characteristics, the problem of finding of the breed features in the genome of animals is becoming more topical. From this point of view, French Bulldog is an interesting breed of dog (FRANC.BULLDOGGE, FCI standard number 101) which belongs by the classification of breeds, adopted in FCI, to the group IX – a dog-companion for health and fun, but to a subgroup of fighting dogs of a small format. French Bulldog breed has been researched slightly not only in Ukraine and also abroad, as the main work of all dog association is focused on solving theoretical and practical issues of breeding, keeping, feeding, veterinary protection and others. The study was conducted at Research Department of Molecular Diagnostic Tests of Ukrainian Laboratory of Quality and Safety of Agricultural Products. 33 animals of French Bulldog breed, admitted to use in dog breeding of Ukrainian Kennel Union (UKU), were involved for the genetic analysis using DNA markers. The materials of the research were buccal epithelial cells, selected before the morning feeding of animals by scraping mucous membrane of oral cavity with disposable, dry, sterile cotton swab. Genomic DNA was extracted using KIT-set of reagents for DNA isolation according to the manufacturer's instructions. PEZ1, PEZ3, PEZ6, PEZ8, FHC 2010, FHC 2054 markers, recommended by International Society for Animal Genetics (ISAG), ACN, КC and FCI, were used for research. As a result of research 25 alleles for all the loci were detected in the experimental sample of dogs. The average number of alleles at the locus Na, obtained by direct counting, was 4.16. The most polymorphic loci for this breed were PEZ6 and PEZ3 with 8 and 6 allelic variants. Monomorphic loci were PEZ8 and FHC 2054 which had 4 and 3 alleles and the lowest level of polymorphism was observed for PEZ 1 and FHC 2010 loci in which only 2 alleles were identified. On analyzing the molecular genetic characteristics of dogs of French Bulldog breed, we found a high variability of genotype on rare alleles, which included alleles: M, C, D, E, J, K, L, O, N and representing 60% of the total number of the identified alleles. C, D, E alleles for PEZ3 locus and O allele at PEZ6 locus are unique to the sampling of dogs because they are not repeated in other loci. Typical alleles: N, F, R, I, P, K, M are 40% of the total. But F, R alleles for PEZ3 locus and P allele for locus PEZ6 are not repeated either in standard allelic variants or in rare one, indicating a high information content of these alleles and loci to be used for further monitoring of allele pool, genetic certification and identification of dogs. Microsatellite DNA loci were analyzed as a result of investigations of French Bulldogs and the most informative: PEZ3, PEZ6 and PEZ8 were found, which have high efficiency in individual and breed certification of dogs due to high variability. These data allow further monitoring of the state of genetic diversity of the breed and the development of measures for improvement of breeding to preserve the structure of breeding material. The study of individual and population genetic variability is advisable to continue for breeding of French Bulldogs "in purity" and preserving valuable gene complexes. The results are the basis for further monitoring of the proposed informative panels of microsatellite DNA markers for genotyping dog of French Bulldog breed and their complex evaluation.


Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 694
Author(s):  
Faith M. Walker ◽  
Rachel Durben ◽  
Stephen M. Shuster ◽  
Richard L. Lindroth ◽  
Thomas G. Whitham

Although genetic diversity within stands of trees is known to have community-level consequences, whether such effects are present at an even finer genetic scale is unknown. We examined the hypothesis that genetic variability (heterozygosity) within an individual plant would affect its dependent community, which adds a new dimension to the importance of genetic diversity. Our study contrasted foliar arthropod community diversity and microsatellite marker-derived measures of genetic diversity of cottonwood (Populus fremontii) trees that had been felled by beavers (Castor canadensis) and were resprouting, relative to adjacent standing, unfelled trees. Three patterns emerged: 1. Productivity (specific leaf area), phytochemical defenses (salicortin), and arthropod community richness, abundance, and diversity were positively correlated with the heterozygosity of individual felled trees, but not with that of unfelled trees; 2. These relationships were not explained by population substructure, genetic relatedness of the trees, or hybridization; 3. The underlying mechanism appears to be that beaver herbivory stimulates increased productivity (i.e., 2× increase from the most homozygous to the most heterozygous tree) that is the greatest in more heterozygous trees. Salicortin defenses in twigs were also expressed at higher concentrations in more heterozygous trees (i.e., 3× increase from the most homozygous to the most heterozygous tree), which suggests that this compound may dissuade further herbivory by beavers, as has been found for other mammalian herbivores. We suggest that high stress to trees as a consequence of felling reveals a heterozygosity–productivity linkage, which in turn is attractive to arthropods. Although experiments are required to demonstrate causality, these results link the genetic diversity of individual trees to community diversity, supporting the hypothesis that interactions among foundation species (beavers and trees) have community-level effects, and underscores the importance of genetic diversity for biodiversity, conservation, and restoration.


Author(s):  
C. Montagnon ◽  
A. Mahyoub ◽  
W. Solano ◽  
F. Sheibani

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.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 671
Author(s):  
Nagaraju Shilpashree ◽  
Sarojinikunjamma Nirmala Devi ◽  
Dalasanuru Chandregowda Manjunathagowda ◽  
Anjanappa Muddappa ◽  
Shaimaa A. M. Abdelmohsen ◽  
...  

Vegetable soybean production is dependent on the development of vegetable type varieties that would be achieved by the use of germplasm to evolve new agronomically superior yielding vegetable type with beneficial biochemical traits. This can be accomplished by a better understanding of genetics, which is why the research was conducted to reveal the quantitative genetics of vegetable soybean genotypes. Genetic variability of main morphological traits in vegetable soybean genotypes and their divergence was estimated, as a result of the magnitude of genotypic variation (GV), and phenotypic variation (PV) of traits varied among the genotypes. All traits showed high heritability (h2) associated with high genetic advance percentage mean (GAM). Therefore, these variable traits are potential for genetic improvement of vegetable type soybean. Genetic diversity is the prime need for breeding, and the magnitude of genetic diversity values were maximized among specific genotypes. Eight clusters were found for all genotypes; cluster VIII and cluster I were considered to have the most diversity. Cluster VIII consisted of two genotypes (GM-6 and GM-27), based on the mean outcomes of the high yield attributing traits. Hence, these two (GM-6, GM-27) genotypes can be advanced for commercial cultivation; furthermore, other genotypes can be used as source of breeding lines for genetic improvement of vegetable soybean.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 342
Author(s):  
Elena Corredoira ◽  
Rita L. Costa

The increasing degradation of forests, together with a higher demand for wood and fruit, has led to the need for more efficient trees adapted to the current climatic conditions and, thus, to the need for genetic improvement programs [...]


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