Quantitative trait loci influencing chemical and sensory characteristics of eating quality in sweet corn.

This study was conducted to ascertain the chromosomal location and magnitude of effect of quantitative trait loci (QTL) associated with the chemical and sensory properties of sweet corn (Zea mays L.) eating quality. Eighty-eight RFLPs, 3 cloned genes (sh1, sh2, and dhn1), and 2 morphological markers (a2 and se1) distributed throughout the sweet corn genome were scored in 214 F2:3 families derived from a cross between the inbreds W6786su1Se1 and IL731Asu1se1. Kernel properties associated with eating quality (kernel tenderness and starch, phytoglycogen, sucrose, and dimethyl sulfide concentrations) were quantified on F2:3 sib-pollinated ears harvested at 20 days after pollination. Sensory evaluation was conducted on a subset of 103 F2:3 families to determine intensity of attributes associated with sweet corn eating quality (corn aroma, grassy aroma, sweetness, starchiness, grassy flavor, crispness, tenderness, and juiciness) and overall liking. Single factor analysis of variance revealed significant QTL for all these traits, which accounted for from 3 to 42% of the total phenotypic variation. A proportion of the RFLP markers associated with human sensory response were also found to be associated with kernel characteristics. To our knowledge this is the first report of the identification of QTL associated with human flavor preferences in any food crop. Key words : sweet corn, RFLP, quantitative trait loci, eating quality, sensory evaluation.