Combining Ability and Heterosis for Agronomic Traits, Husk and Cob Pigment Concentration of Maize

The objective of this study was to identify the maize inbred lines with good general combining ability (GCA), good specific combining ability (SCA), high heterosis for yield and phytochemicals, and the crosses with high yield of yellow kernels and high anthocyanin content in cobs and husk, which was probably related to the high antioxidant activity. The parental lines including five unpigmented females and five pigmented males were crossed in North Carolina design II. The parents, the resulting 25 hybrids, and 5 controls were evaluated at two locations in the dry season of 2016/2017. Additive and non-additive gene effects controlled the inheritance of grain yield, agronomic traits, and phytochemicals. KKU–PFC2 and KKU–PFC4 had the highest GCA effects for phytochemical traits in husk and cob, whereas Takfa1 and Takfa3 were good combiners for grain yield. F1 hybrids had significantly higher total anthocyanin content (TAC), total phenolic content (TPC), (2,2-diphenyl-1-picrylhydrazyl) (DPPH), and trolox equivalent antioxidant capacity (TEAC) in husk and cob than pigmented control cultivars. The hybrids superior for individual traits were identified, but the experiment was not able to identify superior hybrids for multiple traits. The Takfa3 × KKU–PFC5 and NakhonSuwan2 × KKU-PFC4 had the highest anthocyanin in husk and cobs, respectively. The breeding strategies to develop maize varieties with high anthocyanins and normal yellow kernels and utilization of the hybrids are discussed.