Table 1
Composition of nutrient solutions used in the experiments.
| Parameter | Composition | Concentration |
|---|---|---|
| Macronutrients | Ca(NO3)2·4H2O | 2 mM |
| KNO3 | 3 mM | |
| MgSO4·7H2O | 1 mM | |
| NH4H2PO4 | 0.5 mM | |
| Micronutrients | H3BO3 | 46 μM |
| MnSO4·H2O | 9.2 μM | |
| ZnSO4·7H2O | 0.77 μM | |
| CuSO4·5H2O | 0.32 μM | |
| H2MoO4 | 0.12 μM | |
| EDTA-Fe | 50 μM |
Figure 1
Effects of nutrient deficiency on the shoot macronutrient concentrations in BA and AL seedlings. Different letters indicate statistically significant difference between means (p < 0.05). –N, –P and –K indicate media without N, P and K, respectively. AL, Alook (Prunus scoparia L.); BA, bitter almond (Prunus dulcis L.).
Figure 2
Effects of nutrient deficiency on the morphological traits of the shoots of BA and AL seedlings. Different letters indicate statistically significant difference between means (p < 0.05). –N, –P and –K indicate media without N, P and K, respectively. AL, Alook (Prunus scoparia L.); BA, bitter almond (Prunus dulcis L.).
Figure 3
Effects of nutrient deficiency on the root morphological traits of the BA and AL seedlings. Different letters indicate statistically significant difference between means (p < 0.05). –N, –P and –K indicate media without N, P and K, respectively. AL, Alook (Prunus scoparia L.); BA, bitter almond (Prunus dulcis L.).
Figure 4
Effects of nutrient deficiency on SPAD, chlorophyll a, chlorophyll b, total chlorophyll and chlorophyll a/b ratio of the leaves of the BA and AL seedlings. Different letters indicate statistically significant difference between means (p < 0.05). –N, –P and –K indicate media without N, P and K, respectively. AL, Alook (Prunus scoparia L.); BA, bitter almond (Prunus dulcis L.); fw, fresh weight.
Figure 5
Effects of nutrient deficiency on the chlorophyll fluorescence parameters of the leaves of BA and AL seedlings. Different letters indicate statistically significant difference between means (p < 0.05). –N, –P and –K indicate media without N, P and K, respectively. F0, initial fluorescence; Fm, maximum fluorescence; Fv, variable fluorescence; AL, Alook (Prunus scoparia L.); BA, bitter almond (Prunus dulcis L.).
Figure 6
Comparison of plant height of Alook (Prunus scoparia L.) (left) and bitter almond (Prunus dulcis L.) (right) seedlings under nitrogen deficiency (–N) treatment.
Figure 7
Comparison of the root system architectures of bitter almond (Prunus dulcis L.) seedlings in control (left) and N-deficiency (right) treatment.