Quantitative trait loci mapping of seed colour, hairy leaf, seedling anthocyanin, leaf chlorosis and days to flowering in F₂ population of Brassica rapa L.

Abstract

A diversity arrays technology (DArT) map was constructed to identify quantitative trait loci (QTL) affecting seed colour, hairy leaf, seedling anthocyanin, leaf chlorosis and days to flowering in Brassica rapa using a F 2 population from a cross between two parents with contrasting traits. Two genes with dominant epistatic interaction were responsible for seed colour. One major dominant gene controls the hairy leaf trait. Seedling anthocyanin was controlled by a major single dominant gene. The parents did not exhibit leaf chlorosis; however, 32% F 2 plants showed leaf chlorosis in the population. A distorted segregation was observed for days to flowering in the F 2 population. A linkage map was constructed with 376 DArT markers distributed over 12 linkage groups covering 579.7 cM. The DArT markers were assigned on different chromosomes of B. rapa using B. rapa genome sequences and DArT consensus map of B. napus. Two QTL (RSC1-2 and RSC12-56) located on chromosome A8 and chromosome A9 were identified for seed colour, which explained 19.4% and 18.2% of the phenotypic variation, respectively. The seed colour marker located in the ortholog to Arabidopsis thaliana Transparent Testa2 (AtTT2). Two QTL RLH6-0 and RLH9-16 were identified for hairy leaf, which explained 31.6% and 20.7% phenotypic variation, respectively. A single QTL (RSAn-12-157) on chromosome A7, which explained 12.8% of phenotypic variation was detected for seedling anthocyanin. The seedling anthocyanin marker is found within the A. thaliana Transparent Testa12 (AtTT12) ortholog. A QTL (RLC6-04) for leaf chlorosis was identified, which explained 55.3% of phenotypic variation. QTL for hairy leaf and leaf chlorosis were located 0-4 cM apart on the same chromosome A1. A single QTL (RDF-10-0) for days to flowering was identified, which explained 21.4% phenotypic variation.Key words: quantitative trait loci -seed colour -hairy leafseedling anthocyanin -leaf chlorosis -days to floweringBrassica rapa Brassica rapa (AA, 2n = 20) is a major oilseed crop in Indian subcontinent and important vegetable in China and many other countries. It is one of the parent species of rapeseed or canola (Brassica napus, AACC, 2n = 38) and is an excellent model system to study polyploidy-related genome evolution with Arabidopsis thaliana and other Brassica species with larger

The novel gene BrMYB2, located on chromosome A07, with a short intron 1 controls the purple-head trait of Chinese cabbage (Brassica rapa L.)

“…Purple head Chinese cabbage not only has health benefits but also provides an important agronomic trait for germplasm resources. Interestingly, there are different loci that reportedly control the purple trait of Brassica species [19][20][21][22]28,[33][34][35] . Recent investigations of an F 2 population derived from the hybridization of zicaitai and common caixin (B. rapa L. ssp.…”

Investigation of the Genetic Diversity and Quantitative Trait Loci Accounting for Important Agronomic and Seed Quality Traits in Brassica carinata

“…In order to increase the rate of genetic gains in breeding programs, QTL (quantitative trait loci) mapping has been successfully used to identify both qualitative and quantitative loci in several crops including vegetable and oilseed brassicas. QTL for various agronomic traits such as grain yield and its components, flowering time, seed quality, and tolerance to biotic and abiotic stresses have been identified in B. rapa (Rahman et al, 2014 ; Hirani et al, 2016 ), B. juncea (Singh et al, 2012 ; Bagheri et al, 2013 ; Dhaka et al, 2016 ) and B. napus (Snowdon and Friedt, 2004 ; Shi et al, 2009 ; Zou et al, 2010 ; Yong et al, 2015 ; Li et al, 2016 ; Raman et al, 2016 ). However, reports on such analyses in B. carinata has been very limited.…”

Fine mapping of the major QTL for seed coat color in Brassica rapa var. Yellow Sarson by use of NIL populations and transcriptome sequencing for identification of the candidate genes

“…To date, several researchers, such as Lou et al [30], Rahman et al [70, 71], Zhang et al [72], Li et al [17], Xiao et al [33], Bagheri et al [32], Padmaja et al [24], Stein et al [73], Qu et al [74, 75], Hong et al [48], Wang et al[76] and Wang et al [23, 34] have reported a major seed coat color gene or QTL on the chromosome A9 of B . rapa , B .…”