Evaluation of eight white maize inbred lines and their diallel crosses to study the variation in response to water deficit

A half diallel was done among eight white maize inbred lines. Two experiments were laid out in randomized complete block design (RCBD) with three replications to evaluate the eight parental lines and their 28 crosses at both normal and drought stress conditions at Mallawi Agricultural Research Station, Minia, Egypt. Data were recorded for the following traits from 10 guarded plants of each genotype: silking and tassel date to estimate anthesis-silking interval (ASI), plant height (cm), leaf senescence, leaf proline content (mg/g) and grain yield per plant (g) which was adjusted for 15.5% moisture. The effect of irrigation treatments was highly significant for all traits under study except for anthesis-silking interval (ASI), indicating that these traits were affected by water stress. All studied materials were affected by water stress. Nine crosses were selected based on the percentage of yield reduction, three crosses out of them, i.e. Gz-6×Gz-7, Gz-5×Gz-7 and Gz-5×Sd-3 were performed as best crosses under both irrigation systems and selected as tolerant crosses based on mean productivity (MP), stress tolerance index (STI), Geometric mean productivity (GMP) and harmonic mean (MHAR) indices. While, based on drought sensitive index (DSI) and stress tolerance indices, the crosses Gz-6×Sd-3, Gz-2×Gz-4 and Gz-4×Sd-2 were identified as tolerant crosses. Thus, we can use to detect crosses which had high performance under water stress or which had less yield reduction in drought maize breeding programs and can be cultivated in new lands under drip or sprinkler irrigation system.