Agronomic and molecular characterization of some maize hybrids as influenced by water stress and soaking levels of sodium nitro peroxide [electronic resource].

Includes references.

Seven hybrids of maize (Zea mays L.) included three single crosses i.e., SC 120, SC 129, and SC 155 and four three-way crosses, i.e., TWC 310, TWC 311, TWC 314 and TWC 352 were tested under two levels of irrigation intervals, i.e., normal irrigation every 12 days and stress irrigation every 20 days and three levels of antioxidants, i.e., soaking seeds in low (2.5 mM) and high (5mM) concentrations of sodium nitro peroxide solution for 24 h in addition to the control. Soaking treatments were activated by spraying maize plants by sodium nitro peroxide solution after 30 days from planting. Each irrigation treatment was planted in a separate experiment. A split-pl<... design was used, where soaking treatments were assigned to the main plots and hybrids in the sub-plots with four replications. The single cross SC 155 was the earliest in terms of the number of days to 50% tasselled and silking, but SC 120, SC 129, TWC 310, TWC 311, TWC 314, and TWC 352 were the latest under stress irrigation. The same single cross SC 155 had the shortest plant and ear height under normal irrigation, but the single crosses SC 120, SC 129, and TWC 310 had the tallest plants and the highest ear height under stress irrigation. The three way cross TWC 352 had the lowest grain yield followed by TWC 310, TWC 311 and TWC 314 while the single crosses SC 120, SC 129 and SC 155 were the most superior hybrids under stress irrigation in both seasons. Soaking seeds of maize hybrids in sodium nitro peroxide solution was associated with a reduction in plant height at stress irrigation and grain yield at normal irrigation in the first season only. No significant differences were detected among soaking treatments under normal and stress irrigation for other studied traits. Interaction between hybrids and soaking was significant for grain yield under normal irrigation in the first season and plant height besides silking under normal irrigation in the second season. Interaction between hybrids and soaking was not significant for other studied traits. RAPD analysis represented a level of polymorphism of 84.8%. Cluster analysis grouped the selected five hybrids according to their pedigree and also, their drought tolerance. RAPD assay was successful in identifying each of the five hybrids with unique markers, except for TWC 314.

Summary in Arabic.

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