QTL analysis and candidate gene mapping for skin and flesh color in sweet cherry fruit (Prunus avium L.)

Abstract

Sweet cherry (Prunus avium L.) skin and fruit colors vary widely due to differences in red and yellow pigment profiles. The two major market classes of sweet cherry represent the two color extremes, i.e., yellow skin with red blush and yellow flesh and dark mahogany skin with mahogany flesh. Yet, within these extremes, there is a continuum of skin and flesh color types. The genetic control of skin and flesh color in sweet cherry was investigated using a quantitative trait locus (QTL) approach with progeny derived from a cross between cherry parents representing the two color extremes. Skin and flesh colors were measured using a qualitative color-card rating over three consecutive years and also evaluated quantitatively for darkness/lightness (L*), red/green (a*), and yellow/blue (b*). Segregations for the color measurements (card, L*, a*, and b*) did not fit normal distributions; instead, the distributions were skewed towards the color of the darkfruited parent. A major QTL for skin and flesh color was identified on linkage group (LG) 3. Two QTLs for skin and flesh color were also identified on LG 6 and LG 8, respectively, indicating segregation for minor genes. The significance and magnitude of the QTL identified on LG 3 suggests the presence of a major regulatory gene within this QTL interval. A candidate gene PavMYB10, homologous to apple MdMYB10 and Arabidopsis AtPAP1, is within the interval of the major QTL on LG 3, suggesting that PavMYB10 could be the major determinant of fruit skin and flesh coloration in sweet cherry.

A DNA test for fruit flesh color in tetraploid sour cherry (Prunus cerasus L.)

“…For seven of these haplotypes, no significant effect on fruit flesh color was identified. However, four and two of the haplotypes were significantly associated with dark purple-red versus light red/yellow flesh colors in sour cherry, respectively, validating the MYB10-associated fruit flesh color QTL previously identified in sweet cherry (Sooriyapathirana et al 2010). This supports the previous finding that the MYB10 locus on Prunus linkage group 3 is a major factor contributing to sweet cherry red flesh color.…”

“…The 1-5 score represented clear/yellow flesh color (score of 1), through shades of red (scores 2-4) to dark purple-red color (score of 5). Results from the previous analysis conducted in sweet cherry supported this phenotyping strategy (Sooriyapathirana et al 2010) as the color index values were highly significantly correlated with quantitative color measurements obtained using a spectrophotometer, and the color index values were highly significantly correlated across 3 years of evaluation.…”

“…an anthocyanin MYB transcription factor, MdMYB10, was shown to control red fruit flesh and foliage Chagné et al 2007). In sweet cherry, a quantitative trait locus (QTL) associated with the locus that has the highest homology with MdMYB10 (PavMYB10) was identified as the major determinant of red coloration in sweet cherry skin and flesh (Sooriyapathirana et al 2010). This major locus, located on Prunus linkage group 3, controlled as much as 94 % of the variation for sweet cherry flesh color with red flesh dominant to yellow flesh.…”

QTLs detected for individual sugars and soluble solids content in apple

“…This interesting clustering of QTLs may be caused by the tight linkage among separate controlling genes or by the pleiotropic effect of a single gene. The Table 1 Pearson's correlation coefficients (r) among sweetness traits [contents of fructose, glucose, sucrose, sorbitol, and soluble solids content (SSC)] at harvest (H), after 10 weeks (10 weeks), and 20 weeks (20 weeks) of refrigerated storage followed by 1 week at room temperature in 2011 73.3-87.0 ss475882720/ss475877839 3.9 5 clustering of fruit quality QTLs was reported in apple (Liebhard et al 2003;Kenis et al 2008) and other crops in Rosaceae, including peach (Dirlewanger et al 1999;Etienne et al 2002;Quilot et al 2005;Eduardo et al 2013), sour cherry (Wang et al 2000), and sweet cherry (Sooriyapathirana et al 2010). In this study, QTL clustering due to pleiotropy could be explained by a gene coding for a common enzyme involved in sugar metabolism during fruit growth and storage.…”

Molecular genetics of blood‐fleshed peach reveals activation of anthocyanin biosynthesis by NAC transcription factors

“…In apple, two genes, MYB10 and MYB110a, are found to co-segregate with two distinct red-flesh apple phenotypes, termed type 1 and 2, respectively (Chagn e et al, 2007(Chagn e et al, , 2013 (Butelli et al, 2012). In sweet cherry, a major QTL for red flesh color has been anchored onto LG3, and a homolog of apple MYB10 within the interval of this QTL is proposed to be a determinant of fruit skin and flesh coloration (Sooriyapathirana et al, 2010). All these results indicate that the red flesh trait is associated with the activation of MYB regulators.…”