Article at Cogent Food & Agriculture - Genetic Variability, Stability, and Differential Responses of Maize Genotypes to Drought and Salt Stresses During Germination

Research hypothesis
We hypothesized that (1) maize genotypes possess significant genetic variability for germination traits under drought and salt stress, (2) genotype-by-environment (G×E) interactions would cause differential ranking of genotypes across iso‑osmotic PEG (drought) and NaCl (salinity) treatments, and (3) tolerance to PEG‑induced drought and NaCl‑induced salinity at germination are governed by at least partially non‑overlapping genetic mechanisms.

What the data shows
The dataset contains measurements of six seedling traits (shoot length, root length, fresh shoot weight, fresh root weight, dry shoot weight, dry root weight) for 25 maize genotypes tested under four osmotic environments: control (0 MPa), PEG‑6000 20% (~‑0.75 MPa), PEG‑6000 22% (~‑1.0 MPa), and NaCl 200 mM (~‑1.0 MPa), with two replications.
Key findings from the analysis of this dataset include:
1. Significant G×E interaction for five out of six traits (p<0.05).
2. Low broad‑sense heritability (2.2–10.6%) across combined environments, indicating strong environmental modulation.
3. Clear separation of NaCl environment from PEG environments in GGE biplots, with negative or non‑significant rank correlations between NaCl and PEG treatments (e.g., for fresh shoot weight r = –0.41*).
4. Genotypes G14 and G19 showed the best combination of high mean performance and stability (WAASBY ranking).
5. Genotypes G15 and G22 were specifically adapted to drought (PEG), while G3, G11, G13 performed best under salinity (NaCl).

Researchers can use this dataset to:
1. Identify maize genotypes with broad stability or specific adaptation to drought or salt stress during germination.
2. Validate the finding that screening with PEG alone is insufficient to predict salt tolerance.
3. Perform meta‑analyses or comparative studies with other maize panels under osmotic stress.
4. Train genomic prediction models for stress tolerance, provided genotypic data are available.

Sufficient description for reuse
Each row in the dataset corresponds to one experimental unit (25 seeds per roll, with 10 normal seedlings measured). Variables include: Genotype code (G1–G25), Environment (P1=control, P2=PEG‑0.75MPa, P3=PEG‑1.0MPa, P4=NaCl‑1.0MPa), Replication (1 or 2), and the six trait means (cm or g). All measurements followed ISTA rules, using the between‑paper (BP) method at 25±1°C in darkness for 7 days. Dry weights were obtained after 48h at 60°C. The data are raw values (not standardized), allowing flexible re‑analysis (ANOVA, stability models, or multivariate methods).