Table 2.
Efficiency of clover root nodulation by R. leguminosarum sv. trifolii strains examined in a wide range of temperatures.
| Origin of population | Strains | T. (°C) | Average number of nodules per plant (dpi) | ||||
|---|---|---|---|---|---|---|---|
| 7 | 14 | 21 | 28 | 35 | |||
| Temperate climate region | 2-2, 3-1, 3-3, 4-3, 5-8, 6-11, 8-3, 8-11, 10-3, KW1-9, KW2-9, M2, M14, M16, M19, 24.2 | 10 | 0 ± 0(aA) | 0.07 ± 0.05(aB) | 0.93 ± 0.63(aC) | 2.06 ± 1.0(aCD) | 2.82 ± 1.1(aD) |
| 15 | 0 ± 0(aA) | 0.44 ± 0.21(bB) | 1.46 ± 1.16(aBC) | 2.54 ± 1.5(aC) | 3.36 ± 1.1(aC) | ||
| 20 | 0.91 ± 0.54(bA) | 4.02 ± 1.4(cB) | 7.16 ± 3.5(bBC) | 8.95 ± 3.45(bC) | 10.27 ± 2.9(bC) | ||
| 25 | 2.46 ± 0.69(cA) | 5.94 ± 2.1(cB) | 7.68 ± 2.82(bBC) | 10.41 ± 3.9(bC) | 12.22 ± 2.0(bC) | ||
| Subpolar climate region | R1, R13, R23, R26, R32, R41, R49, R51, R53, R56, R66, R70, R108, R118, R137 | 10 | 0 ± 0 (aA) | 0.14 ± 0.1(aB) | 1.31 ± 0.51(aC) | 2.35 ± 0.95(aC) | 3.16 ± 1.54(aCD) |
| 15 | 0 ± 0(aA) | 0.55 ± 0.25(bB) | 1.75 ± 0.9(aC) | 2.80 ± 1.2(aC) | 3.77 ± 0.78(aCD) | ||
| 20 | 0.88 ± 0.22(bA) | 3.29 ± 1.1(cB) | 7.56 ± 2.2(bC) | 10.14 ± 2.85(bC) | 11.66 ± 3.11(bC) | ||
| 25 | 2.39 ± 0.91(cA) | 5.85 ± 1.25(dB) | 8.83 ± 2.3(bB) | 12.81 ± 3.21(bBC) | 16.97 ± 3.83(bC) | ||
Results are presented as mean ± SD. Lower case letters in brackets indicate statistically significant differences (p ≤ 0.05) for each population tested at different temperatures at a particular time point (dpi); upper case letters in brackets indicate statistically significant differences (p ≤ 0.05) for each population tested at particular temperatures at different time points (dpi) (two-way ANOVA, Tukey’s post hoc test). No statistically significant differences (p ≤ 0.05) between two populations tested at each temperature and time point (dpi) were found.