Effect of the different gene combinations on the agronomic and eating quality of special maize (Zea mays L.) types

Special maize types are becoming an important vegetable in the Philippines and its increasing demand in the urban centers has resulted of expansion in nearby production areas. Most of the varieties available in the market are mostly composed of only single gene for flavor especially for sweetness. In the past few years, even in the Philippines, breeders have been trying to combine these genes to boost the sugar levels of the endosperm. The different recessive genotypes still need to be further exploited to further improve the eating quality of special maize types. Development of double mutant genes may provide different degrees of flavor and eating quality. These new gene combinations could represent the future of the special maize type industry in the country. The general objective of the study was to determine the effect of the different gene combinations on the agronomic and eating quality of special maize types. Results showed that the yield of single mutant lines is still higher than the yield of the double mutant lines. Most of the double mutant genes evaluated in the study, however,have better eating quality and flavor than their single mutant gene counterparts. Significant positive correlations were showed by yield with plant height, ear length, ear width and in number of marketable ear. Most of the quality attributes evaluated in this study were found to be positively correlated with each other. Based on those findings, it is concluded that except for the waxy gene, combinations of sugary, shrunken and brittle gene increased the sugar levels of the endosperm. It is further concluded that the double mutants susubtbt and susushsh which exhibited superior eating quality may still be improved as shown by the performance of the parental single mutant sugary. This study indicates that at least for the different genotypes evaluated, it could be possible to develop a double mutant variety of special maize types with better eating quality and acceptable agronomic characteristics.