Stability Analysis and Heterotic Studies in Maize (Zea mays L.) Inbreds to Develop Hybrids With Low Phytic Acid and High-Quality Protein

Maize is a major staple crop with high value as food and feed in the poultry sector. Considering the overall nutritional value, maize-based diets comprise two major constraints, i.e., higher phytic acid (PA) and lack of tryptophan. To overcome these issues, a set of identified stable donors for low PA (lpa) and higher tryptophan were crossed in a line x tester fashion, and the hybrids obtained were evaluated at three locations with two replications. Among the inbreds for yield, UMI 1201 and UMI 1205 were the stable good combiners, and for PA, UMI 447 and LPA-2-285 were identified as efficient combiners across locations. Subsequently, 72 hybrids developed from these inbreds had a reduced phytate and higher tryptophan compared with checks having alterations in their yield levels. From Additive Main Effects and Multiplicative Interaction (AMMI) and Genotype main effect plus genotype-by-environment interaction (GGE) biplots, DMR-QPM-09-13-1 x UMI 1099 (PA:9.38 mg/g, trp:0.06%, and yield:184.35 g) and UMI 1205 x UMI 467 (PA:7.04 mg/g, trp:0.06%, and yield:166.39 g) were stable for their high yield with medium PA and tryptophan. Also, across environments, UMI 1200 x UMI 467 had a stable average yield of 129.91 g along with the lowest PA of 4.50 mg/g and higher tryptophan of 0.07%. Thus, these hybrids could be selected and evaluated in upcoming biofortification trials to benefit the poultry sector. Furthermore, the parental inbreds utilized were grouped into heterotic pools to serve as a source population for the development of lpa hybrids in future programs.