Mapping QTLs for 15 morpho-metric traits in Arabidopsis thaliana using Col-0 × Don-0 population

Abstract

Genome wide quantitative trait loci (QTL) mapping was conducted in Arabidopsis thaliana using F₂ mapping population (Col-0 × Don-0) and SNPs markers. A total of five linkage groups were obtained with number of SNPs varying from 45 to 59 per linkage group. The composite interval mapping detected a total of 36 QTLs for 15 traits and the number of QTLs ranged from one (root length, root dry biomass, cauline leaf width, number of internodes and internode distance) to seven (for bolting days). The range of phenotypic variance explained (PVE) and logarithm of the odds ratio of these 36 QTLs was found be 0.19-38.17% and 3.0-6.26 respectively. Further, the epistatic interaction detected one main effect QTL and four epistatic QTLs. Five major QTLs viz. Qbd.nbri.4.3, Qfd.nbri.4.2, Qrdm.nbri.5.1, Qncl.nbri.2.2, Qtd.nbri.4.1 with PVE > 15.0% might be useful for fine mapping to identify genes associated with respective traits, and also for development of specialized population through marker assisted selection. The identification of additive and dominant effect QTLs and desirable alleles of each of above mentioned traits would also be important for future research.

Keywords: Arabidopsis; Mapping population; Phenotyping; QTL mapping; Single nucleotide polymorphism (SNP).

Fig. 1

Pictorial representation of differences between Col-0 and Don-0 for rosette diameter and biomass (a); number of cauline leaves and internodes (b); plant height (c); trichome density (d); flowering and root biomass (e); cauline leaf (f); rosette leaf (g)

Fig. 2

Representative phenotypic variations in F₂ plants for rosette leaf size, shape and number, bolting, flowering (a); trichome density (b); cauline leaves and plant height (c); root length and biomass (d); internode distance and number (e)

Fig. 3

Frequency distribution of 15 traits in F₂ population. Red and blue stars represent trait value of Col-0 and Don-0 respectively (color figure online)

Fig. 4

Diagrammatic representation of linkage map in five chromosomes constructed in the present study. Position and name of markers are given on left and right side of the bar respectively. Different colors of bar given on right side of marker name represent QTLs for different traits identified through single-locus analysis. QTLs represented by dumbbell were detected through two-locus analysis. Mixed linear composite interval mapping was conducted with QTLNetwork 2.1 software to map QTLs with main effect-QTL (M-QTL) and QTLs joint through linear line exhibiting epistatic interactions (E-QTLs) (color figure online)