Allelic diversity in a novel gene pool of canola-quality Brassica napus enriched with alleles from B. rapa and B. carinata

2010 ◽  
Vol 61 (6) ◽  
pp. 483 ◽  
Author(s):  
S. Chen ◽  
J. Zou ◽  
W. A. Cowling ◽  
J. Meng
Keyword(s):  
Genetic Diversity ◽  
Brassica Napus ◽  
Gene Pool ◽  
First Generation ◽  
Second Generation ◽  
Allelic Diversity ◽  
Type B ◽  
Novel Gene ◽  
New Type ◽  
Canola Quality

Brassica napus is an amphidiploid with genome AACC and is relatively deficient in genetic diversity. The abundant genetic diversity in other A- and C-genome Brassica species is a valuable resource to expand the narrow gene pool of B. napus. Recently the Ar genomic components from Chinese B. rapa (ArAr) and Cc genomic components from Ethiopian mustard B. carinata (BBCcCc) were introgressed into B. napus through interspecific hybridisation, and the Ar/Cc components were enriched through two generations of molecular marker-assisted selection. In this study, the simple sequence repeat (SSR) allelic diversity of 29 of these new-type B. napus lines, 12 from the first generation and 17 from the second generation, was compared with 66 international B. napus varieties from Australia, China and other countries. Hierarchical clustering and two-dimensional multidimensional scaling revealed that second generation lines and a few first generation lines, all selected for high Ar/Cc components, formed a unique population that was distantly separated from international B. napus. This novel gene pool had significantly higher richness of private SSR alleles and more alleles per SSR marker than the international B. napus varieties. The new-type B. napus lines showed variation in agronomic traits beyond the canola-quality B. napus parent. Many of the lines had low erucic acid and low glucosinolates in the seed (canola quality), indicating that they could be utilised immediately in canola breeding programs.

Association mapping of seed oil content in Brassica napus and comparison with quantitative trait loci identified from linkage mappingThis article is one of a selection of papers from the conference “Exploiting Genome-wide Association in Oilseed Brassicas: a model for genetic improvement of major OECD crops for sustainable farming”.

Genome ◽  
2010 ◽  
Vol 53 (11) ◽  
pp. 908-916 ◽  
Author(s):  
Jun Zou ◽  
Congcong Jiang ◽  
Zhengying Cao ◽  
Ruiyuan Li ◽  
Yan Long ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Brassica Napus ◽  
Association Mapping ◽  
Quantitative Trait ◽  
Linkage Mapping ◽  
Oil Content ◽  
Seed Oil ◽  
Type B ◽  
Seed Oil Content ◽  
New Type

Association mapping has been used increasingly in natural populations with rich genetic diversity to detect DNA-based markers that are associated with important agronomic traits. Brassica napus is an important oil crop with limited genetic diversity. “New-type” B. napus that is introgressed with subgenomic components from related species has been developed to broaden the genetic basis of “traditional” B. napus . In this study, new-type B. napus lines and a collection of traditional B. napus varieties from different countries were used as two different populations to evaluate seed oil content and to determine the efficacy of association mapping by comparison with previous study of linkage mapping. Relatively rich genetic diversity, but a higher level of linkage disequilibrium was observed in the new-type B. napus as compared with the traditional B. napus . Similarly, a larger variation in oil content and a greater number of associated markers were detected in the population of new-type B. napus . Meanwhile, more than half of the genetic loci, to which the associated markers corresponded, were located within the quantitative trait loci intervals identified previously in linkage mapping experiments, which demonstrated the power of association mapping in B. napus .

Broadening genetic diversity inBrassica napuscanola: Development of canola-quality springB. napusfromB. napus×B. oleraceavar.alboglabrainterspecific crosses

2015 ◽  
Vol 95 (1) ◽  
pp. 29-41 ◽  
Author(s):  
Habibur Rahman ◽  
Rick A. Bennett ◽  
Ginette Séguin-Swartz
Keyword(s):  
Genetic Diversity ◽  
Brassica Napus ◽  
Erucic Acid ◽  
Allelic Diversity ◽  
Interspecific Crosses ◽  
Glucosinolate Content ◽  
Spring Canola ◽  
Significant Difference ◽  
C Genome ◽  
Canola Quality

Rahman, H., Bennett, R. A. and Séguin-Swartz, G. 2015. Broadening genetic diversity in Brassica napus canola: Development of canola-quality spring B. napus from B. napus × B. oleracea var. alboglabra interspecific crosses. Can. J. Plant Sci. 95: 29–41. The narrow genetic base in spring Brassica napus (AACC) canola is a limitation for continued improvement of this crop. This research focused on broadening of genetic diversity in spring canola by using B. oleracea (CC). Seeds of B. oleracea contain high levels of erucic acid and glucosinolates, which are undesired in canola. Therefore, inheritance of these traits and the prospect of developing spring canola with allelic diversity introgressed from B. oleracea were investigated in B. napus×B. oleracea interspecific progenies. Zero-erucic plants in F2generation occurred at a lower frequency than expected based on segregation involving only the C-genome erucic acid alleles. Selection in F2to F3focused on zero erucic acid, while focus in later generation was for low glucosinolate and B. napus plants. In the F6, 31% zero-erucic families had low glucosinolate content. Flow cytometry analysis of the F8families showed no significant difference from the B. napus parent. Genetic diversity analysis by using simple sequence repeat markers from the C-genome chromosomes showed that the F8families received up to 54% alleles from B. oleracea. The results demonstrate the feasibility of enriching genetic diversity in B. napus canola by using B. oleracea.

Analysis of Genetic Diversity in the Brassica napus L. Gene Pool Using SSR Markers

2005 ◽  
Vol 53 (4) ◽  
pp. 793-802 ◽  
Author(s):  
M. Hasan ◽  
F. Seyis ◽  
A. G. Badani ◽  
J. Pons-Kühnemann ◽  
W. Friedt ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Brassica Napus ◽  
Ssr Markers ◽  
Gene Pool ◽  
Brassica Napus L

Genetic diversity of Canadian elite summer rape (Brassica napus L.) cultivars from the pre- to post-canola quality era

2010 ◽  
Vol 90 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Y -B. Fu ◽  
R K Gugel
Keyword(s):  
Genetic Diversity ◽  
Brassica Napus ◽  
Erucic Acid ◽  
Simple Sequence Repeat ◽  
Genetic Relationships ◽  
Gene Pools ◽  
Sequence Repeat ◽  
Low Erucic Acid ◽  
Simple Sequence ◽  
Canola Quality

The development of canola quality Brassica napus oilseed cultivars was a major achievement of Canadian public oilseed breeding programs. Simple sequence repeat (SSR) markers were applied to assess the genetic diversity of 300 plants representing one landrace introduced from Argentina in 1943, seven Canadian elite cultivars developed and released by Agriculture and Agri-Food Canada since 1954, and two European cultivars that were the source of the low erucic acid and low glucosinolate traits that define canola quality. Application of 22 SSR primer pairs from eight linkage groups detected 88 polymorphic alleles from 33 likely loci. The allelic frequencies in 300 samples ranged from 0.003 to 0.993 and averaged 0.388. The estimates of mean heterozygosity for these cultivars ranged from 0.055 to 0.203 and averaged 0.139. The most SSR variation was detected in the cultivars Argentine, Golden and Oro. A trend of decline in SSR variation was observed over the years of breeding effort. The proportion of total SSR variation residing among the cultivars was 51.4%; between high vs. low erucic acid cultivars 15% and between high vs. low glucosinolate cultivars 21.2%. Pairwise genetic differentiations among these cultivars ranged from 0.140 to 0.819 and averaged 0.500. Cluster analysis revealed that the genetic relationships of these cultivars were consistent with their known pedigrees. These findings are useful for broadening the genetic base of improved B. napus gene pools, selecting genetically diverse genotypes for hybrid combinations, and conserving summer rape germplasm.Key words: Simple sequence repeat, summer rape, Brassica napus, genetic diversity, genetic relationship, genetic structure

scholarly journals Enhancement of genetic diversity in canola-quality Brassica napus and B. juncea by interspecific hybridisation

2008 ◽  
Vol 59 (10) ◽  
pp. 918 ◽  
Author(s):  
C. J. Schelfhout ◽  
J. M. Wroth ◽  
G. Yan ◽  
W. A. Cowling
Keyword(s):  
Genetic Diversity ◽  
Brassica Napus ◽  
Seed Quality ◽  
Morphological Type ◽  
Transgressive Segregation ◽  
F1 Hybrids ◽  
Interspecific Hybridisation ◽  
Paternal Parent ◽  
Total Seed ◽  
Canola Quality

Reciprocal crosses were made between Brassica napus cv. Mystic (canola) and B. juncea JN29 (near canola quality). The F1 hybrids were selfed and backcrossed in all possible combinations to parent plants. The greatest number of selfed fertile progeny were obtained when Mystic was the maternal parent, and its F1 was most successful in backcrosses to Mystic or JN29 as maternal or paternal parent. The predominant morphological type of fertile progeny was B. napus, but several B. juncea morphological types occurred in F2 and BC1-derived lines. F2 : 3 and BC1S0 : 1 progeny showed transgressive segregation for agronomic and seed quality traits in two contrasting field environments. Several of the B. juncea-type progeny had improved seed quality (lower total seed glucosinolates and higher % oleic acid) over the B. juncea parent. Selfing of interspecific hybrids between canola-quality B. napus and B. juncea has the potential to greatly enhance genetic diversity in canola-quality progeny of both species, without the loss of donor alleles that normally occurs with repeated backcrossing.

scholarly journals Comparison of allelic diversity between native gene resource plantings and selections in open-pollinated progeny test of Pinus radiata D. Don.

2014 ◽  
Vol 63 (1-6) ◽  
pp. 213-221 ◽  
Author(s):  
L. Zhang ◽  
N. Huanqiong ◽  
Washington J. Gapare ◽  
S. K. Dillon ◽  
X. Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Artificial Selection ◽  
First Generation ◽  
Early Stage ◽  
Allelic Diversity ◽  
Radiata Pine ◽  
Nucleotide Polymorphisms ◽  
Native Population ◽  
Stem Form ◽  
Mean Values

AbstractGenetic diversity within radiata pine first generation of open-pollinated selections (OPS) from the native resource stands was compared with that observed in native populations to monitor potential changes in genetic diversity during domestication. Genetic diversity was estimated using 58 single nucleotide polymorphisms (SNPs) from 8 expressed genes. Nucleotide diversity maintained in first generation of selections (OPS) (mean π = 0.0036; mean θw= 0.0058) was similar to that found within the native population material (mean π = 0.0043; mean for θw= 0.0065). Likewise, mean values for expected heterozygosity (HE) within and between native population material and OPS were similar (mean = 0.27 ± 0.04) and not significantly different (P = 0.068). Also, the overall distribution of allele frequency classes was not significantly different between native population material and OPS. These results point to no evidence of loss of diversity in OPS due to artificial selection. One possible reason is that the domestication of the OPS is at a very early stage. Another may be that artificial selection in the OPS was based on tree growth and form, not wood properties. The genes selected in this study are mostly involved in cell wall formation, thus genetic diversity of these genes should remain stable between natural population and OPS, unless there was a significant sampling bias in the OPS. Although the SNP information suggests similarities among mainland populations, results from quantitative genetic studies found large provenance differences for growth-, morphological-, stem-form traits, and disease resistance. Determining the threshold at which genetic diversity levels will be significantly reduced during selection should help breeders to make informed decisions regarding the intensity of selection in managed breeding populations as well as gene resource populations.

scholarly journals KERAGAMAN GENETIK TIGA GENERASI IKAN TAMBAKAN (Helostoma temminkii) DALAM PROGRAM DOMESTIKASI

2018 ◽  
Vol 12 (4) ◽  
pp. 295
Author(s):  
Otong Zenal Arifin ◽  
Wahyulia Cahyanti ◽  
Anang Hari Kristanto
Keyword(s):  
Genetic Diversity ◽  
First Generation ◽  
Second Generation ◽  
Breeding Value ◽  
Three Generations ◽  
Freshwater Aquaculture ◽  
As Species ◽  
Species Specific ◽  
Rapd Method ◽  
Research Institute

Suatu penelitian untuk melihat keragaman genetik tiga generasi ikan tambakan dalam program domestikasi telah dilakukan di Balai Riset Perikanan Budidaya Air Tawar dan Penyuluhan Perikanan, Bogor. Tujuan penelitian ini adalah untuk mengevaluasi keragaman genetik generasi tetua/awal (G0), generasi pertama (G1), dan generasi kedua (G2) dalam program domestikasi ikan tambakan. Pengujian keragaman genetik dilakukan dengan metode PCR-RAPD menggunakan tiga primer, yakni OPA-2, OPA-8, dan OPC-2. Hasil yang diperoleh menunjukkan adanya perbedaan jumlah (7-15) dan ukuran fragmen (200-2.800 bp) yang dihasilkan, dengan frekuensi kemunculan alel berkisar antara 0,00-1,00 dari 31 lokus. Enam fragmen dari OPC-2 (1.400 bp, 1.300 bp, 1.100 bp, 800 bp, 600 bp, 500 bp), lima fragmen dari OPA-2 (1.350 bp, 1.000 bp, 900 bp, 800 bp, 520 bp), dan dua fragmen dari OPA-8 (1.000 bp, 550 bp) merupakan fragmen marka spesifik ikan tambakan pada penelitian ini. Keragaman genetik ikan tambakan antar generasi tergolong rendah, dengan nilai persentase polimorfisme berkisar antara 6,45%-35,48% dan nilai heterozigositas berkisar antara 0,03-0,16. Terjadi penurunan polimorfisme dan heterozigositas dari generasi tetua/awal (G0) ke generasi pertama (G1) dan kembali naik pada generasi kedua (G2). Dalam program domestikasi, nilai efektif induk (Ne) sebaiknya lebih dari 100, dengan nilai laju inbreeding (F) tidak lebih dari 0,005.A study to examine the genetic diversity of three generations of kissing gourami under a domestication program has been conducted at the Research Institute for Freshwater Aquaculture and Fisheries Extension, Bogor. The purpose of this study was to evaluate the genetic diversity of the elder generation (G0), first generation (G1), and second generation (G2) of kissing gourami under the domestication program. The genetic diversity examination was conducted through a PCR-RAPD method using three primers, namely OPA-2, OPA-8, and OPC-2. The obtained results indicated a difference in the number (7-15) and size of the fragments (200-2.800 bp) with the frequency of allele occurrence ranged from 0.00 to 1.00 from 31 loci. Six fragments from OPC-2 (1,400 bp; 1,300 bp; 1,100 bp; 800 bp; 600 bp; 500 bp), five fragments from OPA-2 (1,350 bp; 1,000 bp; 900 bp; 800 bp; 520 bp), and two fragments from OPA-8 (1,000 bp; 550 bp) were considered as species-specific markers of kissing gourami. The genetic diversity among the generations of the kissing gourami was low, with the percentage of polymorphism ranged from 6.45% to 35.48% and the value of heterozygosity ranged from 0.03 to 0.16. There was a decrease in polymorphism and heterozygosity values from the elder generation (G0) to the first generation (G1) and increased again but on the second generation (G2). In addition, the effective breeding value (Ne) in a domestication program should be more than 100, and the average of inbreeding value (F) is less than 0.005.

scholarly journals Genetic diversity of Kemerovo pig breed based on microsatellite markers

2021 ◽  
Vol 941 (1) ◽  
pp. 012022
Author(s):  
S M Chydym ◽  
M L Kochneva ◽  
I A Vilgelmi ◽  
K V Zhychaev
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Gene Pool ◽  
Polymorphic Locus ◽  
Allelic Diversity ◽  
Diversity Analysis ◽  
Genetic Diversity Analysis ◽  
Urgent Task

Abstract Today, the urgent task is to preserve the gene pool of local and regional breeds with their special and useful traits. These features allow them to represent an additional reservoir of genetic diversity. Analysis of the genetic diversity of three pig populations (Kemerovo pig breed, Kemerovo × Landrace crossbreds and Kemerovo × Landrace × Pietrain crossbreds) by microsatellites showed that significant allelic diversity is observed for some loci, while for others it is low. The highest number of alleles was in the purebred pigs in comparison with crossbreds. The greatest range of alleles per locus was noted in the three-breed cross pigs. The most polymorphic locus in all populations was SO005, and the least polymorphic was SW72. It was noted that for most loci the observed heterozygosity corresponds to the expected one, while for others a shortage of heterozygotes is detected.

Introgression of allelic diversity from genetically distinct variants of Brassica rapa into Brassica napus canola and inheritance of the B. rapa alleles

2018 ◽  
Vol 69 (1) ◽  
pp. 94 ◽  
Author(s):  
Rohit Attri ◽  
Habibur Rahman
Keyword(s):  
Genetic Diversity ◽  
Brassica Napus ◽  
Brassica Rapa ◽  
Interspecific Cross ◽  
Allelic Diversity ◽  
Interspecific Crosses ◽  
Glucosinolate Content ◽  
Brassica Napus L ◽  
A Genome ◽  
Marker Alleles

Broadening of genetic diversity in spring oilseed Brassica napus L. (AACC, 2n = 38) canola is important for continued improvement of this crop. For this, the vast allelic diversity of the A genome of Brassica rapa L. (AA, 2n = 20) can be utilised. We investigated the prospect of developing canola-quality euploid B. napus lines carrying the alleles of B. rapa from F2 and BC1 (F1 × B. napus) populations of three B. napus × B. rapa interspecific crosses involving one B. napus and three genetically distinct B. rapa parents. In meiosis, the F1 AAC hybrid was expected to show normal segregation for the A genome chromosomes, whereas a range of C chromosomes from zero to nine was expected to be included in the gametes due to random segregation of this haploid set of chromosomes. Subsequent self-pollination, theoretically, should have eliminated the unpaired C chromosomes and resulted in a majority of B. rapa type. However, no B. rapa-type progeny were detected, and all progeny in the F8 conformed to be B. napus type. Correlation between parent and offspring generation, grown in greenhouse or field, was weak to moderate for seed glucosinolate content; however, the simpler genetic control of this trait, involving only the A genome loci, allowed the development of low-glucosinolate lines from this interspecific cross. Of the theoretical number of simple sequence repeat (SSR) marker alleles of B. rapa expected to be present in F4 and F8 populations, about 45% were detected in these populations, suggesting that the loss of these marker alleles occurred prior to the F4 generation. Loss of several SSR loci was also detected in these populations, which probably resulted from homoeologous pairing and rearrangements of the chromosomes of the A and C genomes. Genetic diversity analysis performed on the F8 progeny of two crosses showed that the two populations clustered into distinct groups, which demonstrates that they inherited SSR B. rapa alleles unique to each B. rapa parent. We conclude that B. rapa alleles from diverse sources can be readily incorporated into B. napus progeny by this interspecific crossing method.

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