Identification of QTL Affecting Sugars in Ananas Melon

Abstract

<jats:p>Sucrose, fructose, total sugars and soluble solids are major factors in determining mature melon fruit sweetness. Bulked segregant analysis was utilized to detect RAPD markers associated with QTL for sucrose, total sugars and soluble solids in an F<jats:sub>2</jats:sub> population from the ananas melon cross of Deltex (high sugars) × TGR1551 (low sugars). Sucrose, glucose, fructose and total sugar data were obtained from 108 F<jats:sub>2</jats:sub> plants by means of HPLC. Clear separations for sucrose, total sugars and soluble solids between Deltex and TGR1551 were observed, whereas slight differences for glucose and fructose were found. Continuous distributions for sucrose, total sugars and soluble solids were observed in the F<jats:sub>2</jats:sub> population indicating quantitative inheritance for the sweetness traits. A significant negative correlation was observed between sucrose and glucose (<jats:italic>r</jats:italic> = -25) or fructose (<jats:italic>r</jats:italic> = -0.31). A significant positive correlation was noted between sucrose and total sugars (<jats:italic>r</jats:italic> = 0.80) or soluble solids (<jats:italic>r</jats:italic> = 0.64). Three low and high DNA bulk pairs for sucrose, total sugars and soluble solids were developed. A total of 360 primers were used to simultaneously screen between the low and high bulks, and between Deltex and TGR1551. Sixty-eight RAPD markers were polymorphic for the low and high bulks. Of the 68 markers, 24 were found to be significantly associated with sucrose, total sugars or soluble solids on the basis of single-factor ANOVA. Marker OM15.550 was consistently associated with QTL affecting sucrose, glucose, fructose, total sugars and soluble solids, and accounted for 7% to 25% of the phenotypic variation for the traits. These markers associated with the sugar synthesis QTL could be useful to transfer these genes into a low sugar cultivar to enhance the fruit sweetness.</jats:p>

Identification and Confirmation of RAPD Markers and Andromonoecious Associated with Quantitative Trait Loci for Sugars in Melon

“…Burger et al (2002) reported a single recessive gene controlling sucrose accumulation in melon. Sucrose was found to be positively correlated with TSS (Park et al, 2004b). Intermediate positive correlations of TSS with overall consumer preference, sweetness, fl avor, texture (Lester and Shellie, 1992), and maturation period (Welles and Buitelaar, 1988) were reported.…”

“…(Wechter et al, 1995), the dominant Vat gene for resistance to cotton-melon aphid (Aphis gossypii Glover) (Klingler et al, 2001), and the recessive nsv gene for resistance to melon necrotic spot virus (Morales et al, 2002) in melons. Also, it has been applied in identifying QTL affecting mature melon fruit sweetness, size, and shape traits (Park and Crosby, 2004;Park et al, 2004b).…”

A Genetic Linkage Map including Loci for Male Sterility, Sugars, and Ascorbic Acid in Melon

“…An F 2 population of a 'Deltex' • TGR 1551 cross segregated for economically important traits including sugars, ascorbic acid, fruit size and shape, flesh and seed cavity size, seed size and quantity, and viral and fungal disease resistance (Alvarez et al, 2005;Lopez-Sese and Gomez-Guillamon, 2000;Park et al, 2007aPark et al, , 2007bPark et al, , 2007cSinclair et al, 2006). Some of these traits are not mapped on published linkage maps (Pitrat, 2005(Pitrat, -2006.…”