Fig. 1. Locations of the Norway spruce seed orchards in southern Finland. 1 = Heinämäki (no. 170; 62°13´N, 25°24´E), 2 = Metsä-Ihala (no. 176; 62°12´N, 24°07´E), 3 = Riihimäki (no. 169; 61°53´N, 24°52´E), 4 = Paronen (no. 365; 61°39´N, 26°17´E), 5 = Sillanpää (no. 235; 60°55´N, 26°13´E), 6 = Taavetti (no. 428; 60°56´N, 27°35´E), 7 = Imatra (no. 374; 61°09´N, 28°47´E), 8 = Suhola (no. 403; 62°15´N, 27°42´E) and 9 = Palvaanjärvi (no. 172; 60°48´N, 27°29´E).
Fig. 2. Test plants inoculated in the greenhouse.
| Table 1. Plant species inoculated with Thekopsora areolata spore sources from Finnish seed orchards (nos. 1–8) in the greenhouse a in 2018 and in the laboratory b in 2019. Numbers after the plant species refer to the seed orchard from which the tested plant leaves were collected. In seed orchard no. 9 only plants were collected. | |||||||||
| Test species | Seed Orchard | ||||||||
| 170 1 | 176 2 | 169 3 | 365 4 | 235 5 | 428 6 | 374 7 | 403 8 | 172 9 | |
| No. of spore sources | |||||||||
| Greenhouse a | |||||||||
| Vaccinium myrtillus | 0 | 2 | 1 | 3 | 2 | 4 | 3 | 4 | 0 |
| Vaccinium vitis-idaea | 0 | 2 | 1 | 3 | 2 | 4 | 3 | 4 | 0 |
| Vaccinium uliginosum | 0 | 2 | 1 | 3 | 2 | 4 | 3 | 4 | 0 |
| Arctostaphylos uva-ursi | 0 | 2 | 1 | 3 | 2 | 4 | 3 | 4 | 0 |
| Empetrum nigrum | 0 | 2 | 1 | 3 | 2 | 4 | 3 | 4 | 0 |
| Laboratory b | |||||||||
| Prunus padus 1, 3, 4, 5, 7, 8, 9 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Vaccinium myrtillus 2, 5, 7 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Melampyrum sylvaticum 5 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Vaccinium vitis-idaea 1, 2, 4, 5, 7 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Filpendula ulmaria 5 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Viola tricolor 5 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Fragaria vesca 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Alchemilla vulgaris 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Anthriscus sylvestris 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Paris quadrifolia 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Lupinus polyphyllus 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Equisetum angustifolia 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Sorbus aucuparia 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Silene dioica 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Geranium sylvaticum 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Veronica chamaedrys 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Rubus idaeus 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Maianthemum bifolium 2 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Rubus saxatilis 2 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Trientalis europaea 2 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Seed orchards: Heinämäki 170 1, Metsä-Ihala 176 2, Riihimäki 169 3, Paronen 365 4, Sillanpää 235 5, Taavetti 428 6, Imatra 374 7, Suhola 403 8, Palvaanjärvi 172 9. | |||||||||
Fig. 3. Uredinia of Thekopsora areolata formed on detached leaves of Prunus padus in the laboratory following aeciospore inoculation.
| Table 2. Uredinia formation on detached leaves of the test plants in the laboratory after four-weeks of incubation. Only positive cases on Prunus padus are shown. | |||||||
| Test species | Seed orchard/Spore source | ||||||
| 170 1 | 176 2 | 169 3 | 365 4 | 235 5 | 374 7 | Control | |
| No. of leaves with uredinia/Abundancy of uredinia | |||||||
| Prunus padus | |||||||
| Tree (outside SV 169) | 2/1 | 1/1 | 2/2 | 2/1 | 1/1 | 0/0 | 0/0 |
| Tree (outside SV 172) | 1/1 | 2/1 | 0/0 | 2/1 | 2/1 | 2/1 | 0/0 |
| Tree 4 (SV 170) | 1/1 | 2/1 | 2/1 | 1/1 | 0/0 | 2/1 | 0/0 |
| Tree 6 (SV 365) | 1/1 | 1/1 | 1/1 | 0/0 | 0/0 | 1/1 | 0/0 |
| Tree 8 (SV 235) | 1/1 | 2/1 | 1/1 | 1/1 | 2/1 | 2/1 | 0/0 |
| Tree 9 (SV 235) | 1/1 | 0/0 | 2/1 | 1/1 | 0/0 | 2/1 | 0/0 |
| Tree 10 (SV 235) | 2/2 | 2/1 | 1/1 | 2/1 | 2/1 | 1/1 | 0/0 |
| Tree 11 (SV 235) | 2/2 | 1/2 | 1/2 | 1/1 | 2/2 | 2/2 | 0/0 |
| Tree 13 (SV 374) | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 | 2/1 | 0/0 |
| Tree 16 (SV 403) | 1/1 | 2/1 | 0/0 | 2/1 | 0/0 | 0/0 | 0/0 |
| Abundancy of uredinia: 0 = No uredinia, 1 = Scarce, 2 = Abundant. First numeral refers to the number of leaves with uredinia per plate and the second one to abundancy of uredinia. SV = Seed orchard. For the names of the seed orchards, see Table 1. | |||||||