scholarly journals Construction and Genetic Analysis of a Worldwide Core Collection of Rapeseed

Author(s):  
Yiyi Guo ◽  
Ying Xu ◽  
Tao Yan ◽  
Lixi Jiang ◽  
Jie Dong ◽  
...  

Abstract Rapeseed (Brassica napus) is an important oilseed crop, which is widely planted in the world. In a previous study, we collected 991 accessions of rapeseed from the worldwide germplasm and revealed genetic polymorphisms within these germplasm by whole-genome resequencing. However, management of such a large amount of accessions is time-consuming, laborious and costly. Therefore, we constructed a core collection of rapeseed consisting of 300 worldwide accessions based on their genetic diversity. Compared with 991 accessions, the worldwide core collection showed similar geographic distribution, the proportion of three ecotypes, nucleotide diversity and the associated SNPs of flowering time. Besides, we identified FT ortholog (BnaA02g12130D) and FLC ortholog (BnaA10g22080D) responsible for flowering time and ecotype differentiation through selective sweep analysis and genome-wide association analysis (GWAS) of flowering time using the rapeseed core collection. FT and FLC are two well-known genes regulating flowering time in Arabidopsis. These results indicate that the worldwide core collection can represent the genetic diversity of 991 worldwide accessions, which could be more efficiently used for phenotypic and genetic studies in rapeseed.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luciano Calderón ◽  
Nuria Mauri ◽  
Claudio Muñoz ◽  
Pablo Carbonell-Bejerano ◽  
Laura Bree ◽  
...  

AbstractGrapevine cultivars are clonally propagated to preserve their varietal attributes. However, genetic variations accumulate due to the occurrence of somatic mutations. This process is anthropically influenced through plant transportation, clonal propagation and selection. Malbec is a cultivar that is well-appreciated for the elaboration of red wine. It originated in Southwestern France and was introduced in Argentina during the 1850s. In order to study the clonal genetic diversity of Malbec grapevines, we generated whole-genome resequencing data for four accessions with different clonal propagation records. A stringent variant calling procedure was established to identify reliable polymorphisms among the analyzed accessions. The latter procedure retrieved 941 single nucleotide variants (SNVs). A reduced set of the detected SNVs was corroborated through Sanger sequencing, and employed to custom-design a genotyping experiment. We successfully genotyped 214 Malbec accessions using 41 SNVs, and identified 14 genotypes that clustered in two genetically divergent clonal lineages. These lineages were associated with the time span of clonal propagation of the analyzed accessions in Argentina and Europe. Our results show the usefulness of this approach for the study of the scarce intra-cultivar genetic diversity in grapevines. We also provide evidence on how human actions might have driven the accumulation of different somatic mutations, ultimately shaping the Malbec genetic diversity pattern.


Genome ◽  
2010 ◽  
Vol 53 (11) ◽  
pp. 884-898 ◽  
Author(s):  
Jianjun Zhao ◽  
Anna Artemyeva ◽  
Dunia Pino Del Carpio ◽  
Ram Kumar Basnet ◽  
Ningwen Zhang ◽  
...  

A Brassica rapa collection of 239 accessions, based on two core collections representing different morphotypes from different geographical origins, is presented and its use for association mapping is illustrated for flowering time. We analyzed phenotypic variation of leaf and seed pod traits, plant architecture, and flowering time using data collected from three field experiments and evaluated the genetic diversity with a set of SSR markers. The Wageningen University and Research Centre (WUR) and the Vavilov Research Institute of Plant Industry (VIR) core collections had similar representations of most morphotypes, as illustrated by the phenotypic and genetic variation within these groups. The analysis of population structure revealed five subgroups in the collection, whereas previous studies of the WUR core collection indicated four subgroups; the fifth group identified consisted mainly of oil accessions from the VIR core collection, winter oils from Pakistan, and a number of other types. A very small group of summer oils is described, that is not related to other oil accessions. A candidate gene approach was chosen for association mapping of flowering time with a BrFLC1 biallelic CAPS marker and a BrFLC2 multiallelic SSR marker. The two markers were significantly associated with flowering time, but their effects were confined to certain morphotypes and (or) alleles. Based on these results, we discuss the optimal design for an association mapping population and the need to fix the heterogeneous accessions to facilitate phenotyping and genotyping.


2017 ◽  
Author(s):  
Benjamin Laenen ◽  
Andrew Tedder ◽  
Michael D. Nowak ◽  
Per Toräng ◽  
Jörg Wunder ◽  
...  

Plant mating systems have profound effects on levels and structuring of genetic variation, and can affect the impact of natural selection. While theory predicts that intermediate outcrossing rates may allow plants to prevent accumulation of deleterious alleles, few studies have empirically tested this prediction using genomic data. Here, we study the effect of mating system on purifying selection by conducting population genomic analyses on whole-genome resequencing data from 38 European individuals of the arctic-alpine crucifer Arabis alpina. We find that outcrossing and mixed-mating populations maintain genetic diversity at similar levels, whereas highly self-fertilizing Scandinavian A. alpina show a strong reduction in genetic diversity, most likely as a result of a postglacial colonization bottleneck. We further find evidence for accumulation of genetic load in highly self-fertilizing populations, whereas the genome-wide impact of purifying selection does not differ greatly between mixed-mating and outcrossing populations. Our results demonstrate that intermediate levels of outcrossing may allow efficient selection against harmful alleles whereas demographic effects can be important for relaxed purifying selection in highly selfing populations. Thus, both mating system and demography shape the impact of purifying selection on genomic variation in A. alpina. These results are important for an improved understanding of the evolutionary consequences of mating system variation and the maintenance of mixed-mating strategies.SignificanceIntermediate outcrossing rates are theoretically predicted to maintain effective selection against harmful alleles, but few studies have empirically tested this prediction using genomic data. We used whole-genome resequencing data from alpine rock-cress to study how genetic variation and purifying selection vary with mating system. We find that populations with intermediate outcrossing rates have similar levels of genetic diversity as outcrossing populations, and that purifying selection against harmful alleles is efficient in mixed-mating populations. In contrast, self-fertilizing populations from Scandinavia have strongly reduced genetic diversity, and accumulate harmful mutations, likely as a result of demographic effects of postglacial colonization. Our results suggest that mixed-mating populations can avoid the negative evolutionary consequences of high self-fertilization rates.


2021 ◽  
Author(s):  
Adam Ciezarek ◽  
Antonia Ford ◽  
Graham Etherington ◽  
Kasozi Nasser ◽  
Milan Malinsky ◽  
...  

Cichlid fish of the genus Oreochromis form the basis of the global tilapia aquaculture and fisheries industry. Non-native farmed tilapia populations are known to be widely distributed across Africa and to hybridize with native Oreochromis species. However, many species are difficult to distinguish morphologically, hampering attempts to maintain good quality farmed strains or to identify pure populations of native species. Here, we describe the development of a single nucleotide polymorphism (SNP) genotyping panel from whole-genome resequencing data that enables targeted species identification in Tanzania. We demonstrate that an optimized panel of 96 genome-wide SNPs based on FST outliers performs comparably to whole genome resequencing in distinguishing species and identifying hybrids. We also show this panel outperforms microsatellite-based and phenotype-based classification methods. Case studies indicate several locations where introduced aquaculture species have become established in the wild, threatening native Oreochromis species. The novel SNP markers identified here represent an important resource for assessing broodstock purity and helping to conserve unique endemic biodiversity, and in addition potentially for assessing broodstock purity in hatcheries.


2021 ◽  
Author(s):  
Liu Diao ◽  
Cao Hongzhan ◽  
Lu Chunlian ◽  
Li Shang ◽  
Jia Mengyu ◽  
...  

ABSTRACTShenxian pigs can be divided into two main strains from their shape and appearance: Huangguazui and Wuhuatou. There are significant differences in the phenotypic characters between the two subpopulations. The Shenxian pig, as the only local pig breed listed in China Pig Breeds in Hebei Province, has the excellent traits of Chinese local pigs. In order to explore the genetic diversity and genetic distance of the different subpopulations of Shenxian pig, as well as understand their evolutionary process, whole genome resequencing and genetic structure analyses were performed for the two sub-population types of Shenxian pigs.The results showed that a total of 14,509,223 SNP sites were detected in the Huangguazui type and 13,660,201 SNP sites were detected in the Wuhuatou type. This study’s principal component analysis results showed that the genetic differentiation of the Shenxian pig population was serious, and there was obvious stratification in the population. The phylogenetic tree analysis results indicated that there was a certain genetic distance between the Huangguazui and Wuhuatou types.


2015 ◽  
Vol 38 (5) ◽  
pp. 466-473 ◽  
Author(s):  
Jung-Woo Choi ◽  
Bong-Hwan Choi ◽  
Seung-Hwan Lee ◽  
Seung-Soo Lee ◽  
Hyeong-Cheol Kim ◽  
...  

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