Molecular genetic marker-based analysis of species-differentiated phenotypic characters in an interspecific ryegrass mapping population

The genus Lolium (ryegrasses) exhibits substantial variation between species for annual-perennial growth habit. The genetic bases of this trait, and other characters that are differentiated between taxa, have been investigated through molecular genetic marker-based mapping of an interspecific mapping population derived from pair-wise crossing of single genotypes from Lincoln, a long-lived cultivar of perennial ryegrass, and Andrea, a cultivar of annual-type Italian ryegrass. The Andrea1246 and Lincoln1133 parental maps contained 122 loci on eight linkage groups (LGs), and 169 loci on seven LGs, respectively. A total of 10 phenotypic traits were measured, including annuality-perenniality index, date of head emergence, number of spikes per plant, number of spikelets per spike, number of floret per spike, flag leaf length, flag leaf width, spike length, stem length, and extent of regrowth. A total of 31 putative quantitative trait loci (QTLs) were detected. Regions of significance were identified on Andrea1246 LGs 1, 2, 3 and 6. An annuality-perenniality index QTL on LG2 accounted for ~30% of trait-specific phenotypic variance (Vp). In addition, LG2 contained coincident QTLs for the number of spikes per plant and head emergence date traits. The Lincoln1133 genetic map displayed QTL-containing regions of significance on LGs 1, 4, 5 and 7, accounting individually for 10–22% of Vp. QTLs identified in this study provide potential targets for ryegrass breeding in order to improve vegetative yield, persistence and seed yield.

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Identification of Quantitative Trait Loci Relating to Flowering Time, Flag Leaf and Awn Characteristics in a Novel Triticum dicoccum Mapping Population

Plants ◽

10.3390/plants9070829 ◽

2020 ◽

Vol 9 (7) ◽

pp. 829

Author(s):

Tally I.C. Wright ◽

Angela C. Burnett ◽

Howard Griffiths ◽

Maxime Kadner ◽

James S. Powell ◽

...

Keyword(s):

Genetic Diversity ◽

Quantitative Trait Loci ◽

Flowering Time ◽

Quantitative Trait ◽

Marker Assisted Selection ◽

Mapping Population ◽

Flag Leaf ◽

Snp Array ◽

Leaf Length ◽

Trait Loci

Tetraploid landraces of wheat harbour genetic diversity that could be introgressed into modern bread wheat with the aid of marker-assisted selection to address the genetic diversity bottleneck in the breeding genepool. A novel bi-parental Triticum turgidum ssp. dicoccum Schrank mapping population was created from a cross between two landrace accessions differing for multiple physiological traits. The population was phenotyped for traits hypothesised to be proxies for characteristics associated with improved photosynthesis or drought tolerance, including flowering time, awn length, flag leaf length and width, and stomatal and trichome density. The mapping individuals and parents were genotyped with the 35K Wheat Breeders’ single nucleotide polymorphism (SNP) array. A genetic linkage map was constructed from 104 F4 individuals, consisting of 2066 SNPs with a total length of 3295 cM and an average spacing of 1.6 cM. Using the population, 10 quantitative trait loci (QTLs) for five traits were identified in two years of trials. Three consistent QTLs were identified over both trials for awn length, flowering time and flag leaf width, on chromosomes 4A, 7B and 5B, respectively. The awn length and flowering time QTLs correspond with the major loci Hd and Vrn-B3, respectively. The identified marker-trait associations could be developed for marker-assisted selection, to aid the introgression of diversity from a tetraploid source into modern wheat for potential physiological trait improvement.

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MHC-DRB1/DQB1 Gene Polymorphism and Its Association with Resistance/Susceptibility to Cystic Echinococcosis in Chinese Merino Sheep

Journal of Parasitology Research ◽

10.1155/2014/272601 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 7

Author(s):

Hong Shen ◽

Guohua Han ◽

Bin Jia ◽

Song Jiang ◽

Yingchun Du

Keyword(s):

Genetic Marker ◽

Cystic Echinococcosis ◽

Strong Association ◽

Molecular Genetic ◽

Restriction Enzymes ◽

Chi Square ◽

Exon 2 ◽

Merino Sheep ◽

Dqb1 Gene ◽

Molecular Genetic Marker

The aim of this study was to analyze the relationship between polymorphism of the MHC-DRB1/DQB1 gene and its resistance to Cystic Echinococcosis (C.E), as well as to screen out the molecular genetic marker of antiechinococcosis in Chinese Merino sheep. The MHCII-DRB1/DQB1 exon 2 was amplified by polymerase chain reaction (PCR) from DNA samples of healthy and hydatidosis sheep. PCR products were characterized by restriction fragment length polymorphism (RFLP) technique. Five restriction enzymes (Mval, HaeIII, SacI, SacII, and Hin1I) were employed to cut DRB1, while seven restriction enzymes (MroxI, ScaI, SacII, NciI, TaqI, Mval, and HaeIII) were employed to cut DQB1.Results showed that frequencies of patterns Mvalbb (P<0.01), SacIab in DRB1 exon 2 (P<0.05), and TaqIaa, HaeIIInn (P<0.01) in DQB1 exon 2 were significantly higher in the healthy group compared with the C.E individuals, which implied that there was a strong association between these genotypes and hydatidosis resistance or susceptibility. Chi-square test showed that individuals with the genic haplotype DRB1-SacIab/DRB1-Mvalbb/DQB1-TaqIaa/DQB1-HaeIIInn (P<0.01) were relatively resistant to C.E, while individuals with the genic haplotypes DRB1-Mvalbc/DQB1-Mvalyy/DQB1-TaqIab/DQB1-HaeIIImn (P<0.01) and DRB1-Mvalbb/DQB1-Mvalcc/DQB1-TaqIab/DQB1-HaeIIImn (P<0.01) were more susceptible to C.E. In addition, to confirm these results, a fielding experiment was performed with Chinese Merino sheep which were artificially infected withE.g. The result was in accordance with the results of the first study. In conclusion, MHC-DRB1/DQB1 exon 2 plays an important role as resistant to C.E in Chinese Merino sheep. In addition, the molecular genetic marker of antiechinococcosis (DRB1-SacIab/DRB1-Mvalbb/DQB1-TaqIaa/DQB1-HaeIIInn) was screened out in Chinese Merino sheep.

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