Table 2.
Analysis of variance and means comparison for morphological parameters and anatomical traits in soybean seedlings in response to different biostimulant (B) concentrations (K-0.01, K-0.05, and K-0.5%) and light quality (LQ) regimes (FL, FS, and RB) as well as under 12 different combinations of B × LQ. Different letters within each column indicate significant differences according to Student-Newman-Keuls multiple comparison tests (p < 0.05). Asterisks represent the level of significance for main factors (B, LQ) and their interaction (B × LQ): NS-not significant; * p < 0.05; ** p < 0.01; *** p < 0.001. Seeds treated with H2O served as a control.
| Morphological Parameters | Anatomical Traits | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| TLA | SLA | Lenght | Biomass | S/R | LT | PT | ST | IS | |
| B | |||||||||
| H2O | 20 a | 221 b | 40 a | 0.37 a | 1.47 a | 140 a | 71 a | 48 a | 14 a |
| K-0.01% | 22 a | 215 b | 38 a | 0.37 a | 1.67 a | 134 b | 74 a | 45 a | 15 a |
| K-0.05% | 21 a | 286 a | 40 a | 0.35 a | 1.41 a | 130 c | 73 a | 45 a | 14 a |
| K-0.5% | 23 a | 199 b | 36 a | 0.35 a | 1.37 a | 127 c | 68 b | 45 a | 14 a |
| LQ | |||||||||
| FL | 25 a | 214 b | 38 a | 0.37 a | 1.72 a | 124 c | 69 b | 41 b | 14 a |
| FS | 20 b | 240 a | 41 a | 0.35 a | 1.26 b | 132 b | 70 b | 47 a | 15 a |
| RB | 19 b | 237 a | 37 a | 0.36 a | 1.45 b | 143 a | 76 a | 49 a | 13 b |
| Interaction | |||||||||
| H2O × FL | 21 a | 210 b | 45 a | 0.38 a | 1.89 a | 125 c | 66 d | 41 b | 17 ab |
| K-0.01% × FL | 24 a | 198 b | 40 a | 0.37 a | 1.73 a | 124 c | 67 d | 42 b | 20 ab |
| K-0.05% × FL | 29 a | 271 a | 35 a | 0.36 a | 1.88 a | 131 bc | 82 b | 41 b | 14 b |
| K-0.5% × FL | 27 a | 179 c | 34 a | 0.35 a | 1.41 a | 117 d | 62 e | 39 b | 10 c |
| H2O × FS | 21 a | 206 b | 40 a | 0.38 a | 1.11 a | 147 a | 71 cd | 51 a | 17 ab |
| K-0.01% × FS | 22 a | 224 b | 37 a | 0.37 a | 1.73 a | 127 c | 68 cd | 43 b | 11 bc |
| K-0.05% × FS | 15 a | 299 a | 49 a | 0.33 a | 1.13 a | 129 bc | 70 cd | 52 a | 13 b |
| K-0.5% × FS | 23 a | 232 b | 37 a | 0.37 a | 1.10 a | 126 c | 70 cd | 44 b | 20 a |
| H2O × RB | 19 a | 248 b | 34 a | 0.36 a | 1.41 a | 149 a | 75 c | 51 a | 8.3 c |
| K-0.01% × RB | 20 a | 226 b | 41 a | 0.39 a | 1.56 a | 152 a | 87 a | 51 a | 18 a |
| K-0.05% × RB | 19 a | 291 a | 35 a | 0.35 a | 1.22 a | 132 bc | 70 cd | 42 b | 14 b |
| K-0.5% × RB | 18 a | 185 c | 39 a | 0.39 a | 1.62 a | 139 b | 72 cd | 54 a | 12 b |
| Significance | |||||||||
| B | NS | *** | NS | NS | NS | *** | *** | NS | NS |
| LQ | * | * | NS | NS | *** | *** | *** | *** | ** |
| B × LQ | NS | * | NS | NS | NS | *** | *** | *** | *** |
TLA: total leaf area (cm2); SLA: specific leaf area (cm2g−1); Length: total seedling length (cm); Biomass: total seedling biomass (g DW); S/R: shoot/root biomass allocation; LT: leaf thickness (µm); PT: palisade thickness (µm); SP: spongy thickness (µm); IS: intercellular spaces (%).