Genetic Diversity and Population Structure of Tetraploid Accessions of the <i>Medicago sativa–falcata</i> Complex

The genus Medicago is an important component of legumes and includes the model legume barrel‐clover (Medicago truncatula Gaertn.) and widely cultivated forage crop alfalfa (M. sativa L.). The complex taxonomic group known as the M. sativa species complex, or M. sativa–falcata species complex, includes a number of taxa along with cultivated alfalfa that naturally distributed throughout northern Eurasia. Largely because of the millennia‐long economic importance, the taxa have been in the center of attention. In the context of the efforts to understand taxonomic units included in the complex, a wide range of tools have been exploited. The early tools available were morphological traits such as flower color, pod shape, and pollen shape. The large conflict and discrepancy among researchers regarding the statue of the taxa sourced from the fact that a few genes controlled each of the morphological traits used. Thus, the morphology‐based classification was proved to be contradictory. As the molecular tools became available and the research intensified, the initial species status generously granted to the taxa was questioned, and all the taxa denoted as species earlier were relegated to subspecific level. We are aiming to provide an up‐to‐date comprehensive picture for the complex in the light of recent molecular studies.

show abstract

“…× varia was found to be not as ostensible as that of diploid subsp. × hemicycla (İlhan et al., 2016).…”

Section: The Origin and Evolution Of The Complexmentioning

confidence: 99%

Medicago sativa species complex: Revisiting the century‐old problem in the light of molecular tools

Şakiroğlu

İlhan

2021

Crop Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…The genetic differences between subpopulations are large. Identification of good individual plants cannot necessarily be based on morphology (İlhan, Li, Brummer, & Şakiroğlu, 2016). QTL mapping has the potential to identify markers associated with phenotypes.…”

Section: Qtl Implicated For Alfalfa Breedingmentioning

confidence: 99%

Construction of high‐density genetic linkage map and mapping quantitative trait loci (QTL) for flowering time in autotetraploid alfalfa (Medicago sativa L.) using genotyping by sequencing

Zhang

Long

et al. 2020

The Plant Genome

View full text Add to dashboard Cite

Flowering time is an important agronomic trait of alfalfa (Medicago sativa L.). Managing flowering time can produce economic benefits for farmers. To understand the genetic basis of this trait, quantitative trait loci (QTL) mapping was conducted in a full-sib population that consisted of 392 individuals segregating based on flowering time. High density linkage maps were constructed using single nucleotide polymorphism (SNP) markers generated by genotyping-bysequencing (GBS). The linkage maps contained 3,818 SNP markers on 64 linkage groups in two parents. The average marker density was 4.33 cM for Parent 1 (P1) and 1.47 cM for Parent 2 (P2). Phenotypic data for flowering time was collected for three years at one location. Twenty-eight QTLs were identified associated with flowering time. Eleven QTLs explained more than 10% of the phenotypic variation. Among them, five main effect QTLs located on linkage group (LG) 7D of P1 and five main effect QTLs located on LG 6D of P2 were identified. Three QTLs were co-located with other QTLs. The identified linked markers to QTLs could be used for marker-assisted selection in breeding programs to develop new alfalfa varieties to modulate flowering time. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

show abstract

“…caerulea and diploid ssp. falcata has been previously revealed by nuclear markers [ 37 – 39 ]. Moreover, relationships uncovered among diploid members of the M. sativa species complex based on chloroplast DNA sequence analysis supports the recognition of ssp.…”

Section: Discussionmentioning

confidence: 99%

Karyotypic evolution of the Medicago complex: sativa-caerulea-falcata inferred from comparative cytogenetic analysis

Wang

Zhao

et al. 2017

BMC Evol Biol

View full text Add to dashboard Cite

BackgroundPolyploidy plays an important role in the adaptation and speciation of plants. The alteration of karyotype is a significant event during polyploidy formation. The Medicago sativa complex includes both diploid (2n = 2× = 16) and tetraploid (2n = 2× = 32) subspecies. The tetraploid M. ssp. sativa was regarded as having a simple autopolyploid origin from diploid ssp. caerulea, whereas the autopolyploid origin of tetraploid ssp. falcata from diploid form ssp. falcata is still in doubt. In this study, detailed comparative cytogenetic analysis between diploid to tetraploid species, as well as genomic affinity across different species in the M. sativa complex, were conducted based on comparative mapping of 11 repeated DNA sequences and two rDNA sequences by a fluorescence in situ hybridization (FISH) technique.ResultsFISH patterns of the repeats in diploid subspecies caerulea were highly similar to those in tetraploid subspecies sativa. Distinctly different FISH patterns were first observed in diploid ssp. falcata, with only centromeric hybridizations using centromeric and multiple region repeats and a few subtelomeric hybridizations using subtelomeric repeats. Tetraploid subspecies falcata was unexpectedly found to possess a highly variable karyotype, which agreed with neither diploid ssp. falcata nor ssp. sativa. Reconstruction of chromosome-doubling process of diploid ssp. caerulea showed that chromosome changes have occurred during polyploidization process.ConclusionsThe comparative cytogenetic results provide reliable evidence that diploid subspecies caerulea is the direct progenitor of tetraploid subspecies sativa. And autotetraploid ssp. sativa has been suggested to undergo a partial diploidization by the progressive accumulation of chromosome structural rearrangements during evolution. However, the tetraploid subspecies falcata is far from a simple autopolyploid from diploid subspecies falcata although no obvious morphological change was observed between these two subspecies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-017-0951-x) contains supplementary material, which is available to authorized users.

show abstract

Genetic Diversity and Population Structure of Tetraploid Accessions of the Medicago sativa–falcata Complex

Cited by 18 publications

References 44 publications

Medicago sativa species complex: Revisiting the century‐old problem in the light of molecular tools

Medicago sativa species complex: Revisiting the century‐old problem in the light of molecular tools

Construction of high‐density genetic linkage map and mapping quantitative trait loci (QTL) for flowering time in autotetraploid alfalfa (Medicago sativa L.) using genotyping by sequencing

Karyotypic evolution of the Medicago complex: sativa-caerulea-falcata inferred from comparative cytogenetic analysis

Contact Info

Product

Resources

About