Inoculation of known and potential alternate hosts with Peridermium pini and Cronartium flaccidum aeciospores

Inoculations of eight Pinus species with Cronartium and Peridermium stem rusts

“…Inoculation of the seedlings 2.2.1. Experiment 1 Seedlings of P. mugo, P. peuce, P. cembra, P. contorta and a 2-year-old P. sylvestris provenance were inoculated with 6 P. pini aeciospore sources (one source per block, except 4 sources for a P. contorta provenance) collected from severely infected Scots pine stands from various geographic rust populations in 2000 (Table 1; see also Hantula et al, 1998Hantula et al, , 2002Kaitera et al, 1999;Kaitera, 2003). The aeciospores did not infect entire plants of V. hirundinaria Medicus when tested along with earlier inoculations in the greenhouse (Kaitera and Nuorteva, 2003).…”

“…The aeciospores (Table 1) were selected from known C. flaccidum populations (Hantula et al, 1998;Kaitera et al, 1999;Kaitera and Nuorteva, 2003) and collected in June. Thereafter, whole plant leaves of susceptible alternate hosts, Paeonia anomala L. and V. hirundinaria, growing in plastic pots, were inoculated by dusting aeciospores on their leaves in the greenhouse (Kaitera and Nuorteva, 2003).…”

The effect of storage temperature, time and spore source on the germination of Cronartium flaccidum and Peridermium pini aeciospores in vitro

“…In addition, C. flaccidum was found to produce vesicles less frequently than P pini regardless of the storage temperature, time or medium used. According to Gibbs et al (1988) and Kaitera et al (1999), there is high variation in vesicle formation between P pini and C. flaccidum, with P pini producing vesicles more frequently than C. fla ccidum. In the present study, the formation of vesicles was greatly reduced when storage was arranged at high temperatures, but their formation remained relatively unaltered after storage at lower temperatures.…”

“…The aeciospores represented four geographic P pini populations (Jokela 1, Kesalahti 2, Inari, Pudasjarvi) and one C. flaccidum population (Kolari 1) in Finland (for identification of the rust populations, see Hantula et al 1998 andKaitera et al 1999). Shortly after collection, the aeciospores were air-dried and sieved through a fine mesh onto petri dishes just before storage.…”

“…G. Winter are among the most destructive pathogens damaging Scots pine (Pinus sylvestris L.) in Scandinavia (J0rstad 1928, Rennerfelt 1943. In Finland, P pini is the dominating species, but C. flaccidum occurs also sporadically across the country (Liro 1908, Kaitera et al 1999). …”