Performance of 30 Maize Double Haploid Lines Under Drought Stress and Soil Conditioners

Abstract

Background: Doubled haploid (DH) lines are widely employed in maize breeding programs to investigate the genetic and phenotypic characteristics of the lines under drought-stressed soil and various conditions. Agronomic performance and enhanced haploid inducer ability are always sought after through genetic development.

Objective:  The study aimed to investigate the impact of drought stress and soil conditioners on the agronomic performance of 30 doubled haploid (DH) maize lines (were developed by Haploid inducers using 8 populations) under different irrigation levels and soil conditions.

Materials and Method: Two drought stress levels and two hydrogel levels with three replicates were used in a factorial experiment. In this experiment, dripper was used to implement a drip irrigation system. The experiment was conducted using a split-split plot design with three replications.  Main plots were devoted to irrigation levels, two soil conditions was located sub plot and 30 DH lines were located in sub-sub plots. The drought stress levels were the normal condition (100% of field capacity) and the drought stress (75%) of normal condition respectively were design with three replicates.

Results: The results discuss the identification of agronomic and yield traits  in a 30 set of multiple DH populations, as well as under drought stress and non-stress conditions; shown that mean squares due to DHL were significant (P≤ 0.01) for all studied traits, suggesting existence of genetic differences among lines for all studied characters. This also indicates that lines will be differ in their cross combinations, i.e. in their hybrid ability. Also for the Mean squares due interaction  between (lines (L) × irrigation regimes (I)) were significant (P ≤ 0.01) for all studied traits, except KPR, suggesting that lines behaved differently under different water irrigation  for most studied traits and indicating the possibility of selecting  lines for improved performance under a specific drought stress. Mean grain yield per plant (GYPP) was significantly (P ≤ 0.01) reduced due to water stress (75%) water irrigation by 5.01% (96.76g) compared with the normal irrigation which recorded 102.37 g . Under water stress, plant height and ear height were reduced by 29% and 7.61%, respectively, compared with normal irrigation, while kernel weight is reduced by 0.79% compared with 100% irrigation. Furthermore, DTA, DTS, and ASI exhibited shorter days to flowering under water stress.

Conclusion: There were significant genetic variations between the DH lines for every variable that was examined, suggesting that lines could be chosen for better performance under particular drought stress conditions. The work offers insightful information about the application of DH lines in maize research as well as the discovery of genomic areas linked to drought stress and agronomic features in various DH lines.