scholarly journals Application of molecular markers in livestock improvement

2010 ◽  
Vol 26 (3-4) ◽  
pp. 135-154 ◽  
Author(s):  
A. Teneva ◽  
M.P. Petrovic

With recent developments in DNA technologies, a large number of genetic polymorphisms at DNA sequence level has been introduced over the last decades as named DNA-based markers. The discovery of new class of DNA profiling markers has facilitated the development of marker-based gene tags, mapbased cloning of livestock important genes, variability studies, phylogenetic analysis, synteny mapping, marker-assisted selection of favourable genotypes, etc. The most commonly used DNA-based markers have advantages over the traditional phenotypic and biochemical markers since they provide data that can be analyzed objectively. In this article the main applications of molecular markers in present-day breeding strategies for livestock improvement - parentage determination, genetic distance estimation, genetic diversity, gene mapping and marker-assisted selection have been reviewed.

2020 ◽  
Author(s):  
Yusen Shen ◽  
Jiansheng Wang ◽  
Huifang Yu ◽  
Xiaoguang Sheng ◽  
Zhenqing Zhao ◽  
...  

Abstract Background: Broccoli (Brassica oleracea var. italica) is a vegetable widely cultivated in China. Many new-type broccoli cultivars were bred and developed by Chinese breeders during the recent three decades. However, the broccoli cultivar nomenclature and detailed information of genetic relationships among broccoli germplasms are unclear. Results: The present study identified millions of SNPs by next-generation sequencing of 23 representative broccoli lines. Through several steps of selection, 100 SNPs were successfully converted into KASP markers, and used to evaluate the genetic diversity, genetic relationship, and population structure of 392 broccoli accessions, which represent the mainly broccoli breeding materials in China. The initial, introduced and improved accessions were well clustered, though some accessions were overlapped between groups, probably reflecting the fact that breeding activities led to genetic similarities. To make the KASP genotyping more efficient and cost-effective, 25 of the 100 KASPs were selected for fingerprinting of all accessions, and the 2D barcode contained fingerprinting information were generated for elite varieties. Conclusion: The KASP markers developed in this study provided an efficient way for germplasm characterization, DNA fingerprinting, seed purity identification, and marker-assisted selection of broccoli in China.


2007 ◽  
pp. 117-122 ◽  
Author(s):  
A. Peil ◽  
M.-V. Hanke ◽  
H. Flachowsky ◽  
K. Richter ◽  
T. Garcia ◽  
...  

Author(s):  
Luiz Sergio Costa Duarte Filho ◽  
Danielson Ramos Ribeiro ◽  
Allison Vieira da Silva

The species Myrciaria floridunda O. Berg, popularly known as cambuí, belongs to the Myrtaceae family. Cambui is a native, non-endemic species that occur in diverse environments in Central America and South America. They are slow-growing plants with a shrub or sub-shrub habit. The fruits, the product of interest of the species, are small, spherical berries orange or red in colorturning to wine colorwhen they are ripe. The exploitation of the species is still mostly extractivist, carried out by traditional local families who, in times of fruiting of the species, leverage their income by selling fruits at fairs. The fruits can be eaten fresh, in the form of jellies, liquor or wine. To study the genetic diversity of the species using ISSR-type molecular markers, it is necessary to first isolate DNA in sufficient quality and quantity. Here, leaves for DNA extraction were collected from the active germplasm bank of the Federal University of Alagoas, Brazil. The DNA of the species was extracted using CTAB detergent methodology with modifications adapted to the species. Twelve ISSR primers were tested on DNA from two cambui genotypes. Of the twelve primers, eight were selected due to their polymorphism index above 50%, namely: UFAL-2, UFAL-3, UFAL-5, UFAL-6, UFAL-7, UFAL-8, UFAL-9 and UFAL-10.


2007 ◽  
pp. 100-104
Author(s):  
Stella Molnár ◽  
Zsuzsanna Galbács ◽  
Gábor Halász ◽  
Sarolta Hoffmann ◽  
Anikó Veres ◽  
...  

Incorporation of competitive quality and resistance against the most important fungal diseases (powdery and downy mildew) in a cultivar is one of the most important aims of grapevine breeding. In the 20th century, the most advanced results in grapevine resistance breeding were achieved by French researchers. They used resistant cultivars in more than 30% of their growing areas. In these varieties, North American wild Vitisspecies were the resistance gene sources. The discovery of immunity-like resistance of Muscadinia rotundifolia opened new perspectives in resistance breeding. M. rotundifolia harbours a dominant powdery mildew gene, providing resistance in highquality cultivars after back-crosses with V. vinifera varieties. M. rotundifolia has been involved in the Hungarian grape breeding programs since 1996, thanks to a French-Hungarian variety exchange. In addition to traditional selection methods, application of MAS (Marker Assisted Selection) based on various types ofmolecular markers, can provide additional tools for these efforts. Run1 locus, responsible for powdery mildew resistance, was identified in Muscadinia rotundifolia. Molecular markers closely linked to this locus are very significant in screening progenies deriving from M. rotundifolia and V. vinifera crosses, making possible the discrimination between resistant and susceptible genotypes at DNA level. In our analyses BC5 progeny of {(M. rotundifola×V. vinifera) BC4}×Cardinal (V. vinifera) tested for powdery symptoms were analysed with PCR-RFLP (GLP1- 12P1P3) and microsatellite markers (VMC4f3.1, VMC8g9). Our results proved the applicability of the linked markers and reliability of marker assisted selection.


2021 ◽  
Author(s):  
Rajitha Jayakumar Nair ◽  
Manoj Kumar Pandey

Molecular markers are effective tools used to ‘flag’ the location of a specific gene or the inheritance of a definite trait. Markers are unique DNA fragments that can be identified inside the entire genome. The development of molecular markers combined with high throughput technologies have paved the way for achieving the desirable traits as well as induced biotic and abiotic stress tolerance in plant, which enhanced the crop breeding. Highly polymorphic molecular markers are developed for gene mapping, estimation of genetic diversity, finding out the evolution and phylogeny of crop, analysis of heterosis, assessment of diploid/haploid crops and genotyping of cultivars along with Marker Assisted Breeding (MAB)/Marker Assisted Selection (MAS). These are the most significant objectives for crop breeding. This review reveals about the role of various recently developed molecular markers in the improvement of crop. Molecular markers act as a “milestone” for the researchers who aim to enhance crop breeding.


2022 ◽  
pp. 1-6
Author(s):  
Susheel Sharma ◽  
Aejaz Ahmad Dar ◽  
Sachin Gupta ◽  
Ravinder Singh

Abstract Powdery mildew (PM) is one of the most severe fungal diseases of cucumber that limits its production worldwide. In this study, 140 genotypes of cucumber were screened for disease resistance under field and artificial conditions, and then validated with eight known SSR markers linked to PM resistance. Among these genotypes, genotype GS140 was found resistant (R), whereas GS148, GS16 and GS70 were moderately resistant, and GS169 was found to be tolerant. Of all the eight markers, only C31, C80, C162, SSR16472 and SSR16881 amplified the reported linked allele. The 127 bp allele of SSR16881 was found to be associated with the lowest disease severity of 37.65%. The associated markers could further be verified for their usability using linkage studies and the contrast genotypes in the present study could serve as a tool for selection in future marker-assisted selection breeding strategies for PM resistance.


2002 ◽  
Vol 53 (3) ◽  
pp. 239 ◽  
Author(s):  
M. Z. Z. Jahufer ◽  
M. Cooper ◽  
J. F. Ayres ◽  
R. A. Bray

A major challenge faced by today’s white clover breeder is how to manage resources within a breeding program. It is essential to utilise these resources with sufficient flexibility to build on past progress from conventional breeding strategies, but also take advantage of emerging opportunities from molecular breeding tools such as molecular markers and transformation. It is timely to review white clover breeding strategies. This background can then be used as a foundation for considering how to continue conventional plant improvement activities and complement them with molecular breeding opportunities. In this review, conventional white clover breeding strategies relevant to the Australian dryland target population environments are considered. Attention is given to: (i) availability of genetic variation, (ii) characterisation of germplasm collections, (iii) quantitative models for estimation of heritability, (iv) the role of multi-environment trials to accommodate genotype-by-environment interactions, (v) interdisciplinary research to understand adaptation to dryland environments, (vi) breeding and selection strategies, and (vii) cultivar structure. Current achievements in biotechnology with specific reference to white clover breeding in Australia are considered, and computer modelling of breeding programs is discussed as a useful integrative tool for the joint evaluation of conventional and molecular breeding strategies and optimisation of resource use in breeding programs. Four areas are identified as future research priorities: (i) capturing the potential genetic diversity among introduced accessions and ecotypes that are adapted to key constraints such as summer moisture stress and the use of molecular markers to assess the genetic diversity, (ii) understanding the underlying physiological/morphological root and shoot mechanisms involved in water use efficiency of white clover, with the objective of identifying appropriate selection criteria, (iii) estimation of quantitative genetic parameters of important morphological/physiological attributes to enable prediction of response to selection in target environments, and (iv) modelling white clover breeding strategies to evaluate the opportunities for integration of molecular breeding strategies with conventional breeding programs.


Genetika ◽  
2007 ◽  
Vol 39 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Dejana Saftic-Pankovic

The results of the application of molecular markers in sunflower breeding obtained in the Institute of Field and Vegetable Crops in the last decade are reviewed. Our results on genetic distance (GD=7-75%) between sunflower inbred lines obtained with RAPD and SSR markers, indicate large variability and provide important information for the selection of parental lines for future crosses. Interspecific hybridization is often used in sunflower breeding. As only some populations of H. giganteus and H. maximiliani are resistant to sunflower diseases, the investigation of genetic variability in/between two species is of interest. The results obtained with SSR markers are presented. The successful hybridization between H. rigidus and H. annuus was confirmed with RAPD markers, and the variability between F1 and BC1F1 plants is discussed. Desirable alleles and haplotypes can be detected with molecular markers both in early phases of plant development and in early phases of the production of improved lines, which reduces or completely eliminates the large number of testing cycles for desirable phenotypes. CAPS markers for resistance to downy mildew, that can be used in marker assisted selection are presented. .


2018 ◽  
Author(s):  
John Damien Platten ◽  
Joshua N. Cobb ◽  
Rochelle E. Zantua

AbstractDespite strong interest over many years, the usage of quantitative trait loci in plant breeding has often failed to live up to expectations. A key weak point in the utilisation of QTLs is the “quality” of markers used during marker-assisted selection (MAS): unreliable markers result in variable outcomes, leading to a perception that MAS products fail to achieve reliable improvement. Most reports of markers used for MAS focus on markers derived from the mapping population. There are very few studies that examine the reliability of these markers in other genetic backgrounds, and critically, no metrics exist to describe and quantify this reliability. To improve the MAS process, this work proposes five core metrics that fully describe the reliability of a marker. These metrics give a comprehensive and quantitative measure of the ability of a marker to correctly classify germplasm as QTL[+]/[-], particularly against a background of high allelic diversity. Markers that score well on these metrics will have far higher reliability in breeding, and deficiencies in specific metrics give information on circumstances under which a marker may not be reliable. The metrics are applicable across different marker types and platforms, allowing an objective comparison of the performance of different markers irrespective of the platform. Evaluating markers using these metrics demonstrates that trait-specific markers consistently out-perform markers designed for other purposes. These metrics also provide a superb set of criteria for designing superior marker systems for a target QTL, enabling the selection of an optimal marker set before committing to design.


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