Genetics, physiology and sensory perception of sweet corn eating quality

This thesis consists of four related experiments concerned with the study of the genetics, physiology and sensory perception of sweet corn eating quality. The first study provided preliminary information about which sensory attributes are more important in determining eating quality as well as which kernel characteristics were associated with these sensory attributes. In the second study extensive genetic variability was found among endosperm mutations and among genetic backgrounds within different endosperm mutations for kernel characteristics related to sweet corn eating quality. Based on this information two inbreds that differed in kernel characteristics were selected and crossed to generate an $\rm F\sb3$ segregating generation which was used for sensory and genetic studies.In the third experiment using this $\rm F\sb3$ generation, several kernel characteristics such as kernel sucrose concentration or cooked kernel tenderness were found to be highly associated with the panelist perception of sweetness and tenderness. This information suggests that sweet corn eating quality could be improved by selection of superior genotypes based on kernel characteristics. Although sweet corn eating quality was mainly affected by sweetness and tenderness, other sensory attributes such as crispness, starchiness or sweet corn aroma are also important in determining panel preference for sweet corn.The results from the last study demonstrated that RFLP markers in combination with physiological, chemical and sensory evaluation studies can be effectively used in identifying and locating QTL influencing the expression of physiological and chemical traits related to eating quality in sweet corn. These results, along with many previously published studies, suggests a model for quantitative inheritance in which effects of individual factors (QTL) range from qualitative genes with major influence on the phenotype to loci with nearly undetectable effects. The se1 gene which influenced both kernel characteristics and sensory attributes was located in the long arm of chromosome 2.The identification of RFLP markers linked to genes influencing sweet corn eating quality combined with a better understanding of the relationships between kernel characteristics and sensory attributes, could be very helpful in designing breeding programs using marker assisted selection to develop sweet corn germplasm with improved fresh eating quality.U of I OnlyETDs are only available to UIUC Users without author permissio