Susceptibility of Pedicularis spp. to Cronartium ribicola and C. flaccidum in Finland

Abstract

Aeciospores of Cronartium ribicola and C. flaccidum were collected from several locations in Finland and used to inoculate Pedicularis spp. and some known and suspected alternate hosts in 2008-2009. In all trials, C. ribicola formed uredinia and telia on leaves of Ribes nigrum. No uredinia or telia of C. ribicola formed on older leaves of Pedicularis spp. but both uredinia and telia were found on young leaves of P. palustris ssp. palustris. Cronartium flaccidum produced uredinia and ⁄ or telia on leaves of P. palustris ssp. palustris, P. lapponica, Vincetoxicum hirundinaria and Melampyrum sylvaticum. Neither rust infected P. sceptrum-carolinum, Vaccinium myrtillus, Calluna vulgaris or Ledum palustre. Similar to rusts in Asia and North America, the results showed that European C. ribicola exhibit more variable host reactions and wider alternate host ranges than earlier described. Pedicularis palustris may play a role in the spread of Cronartium in natural forests.

Nasa, Nemesia and Euphrasia: new alternate hosts of Cronartium spp.

“…Similar to our earlier results (Kaitera & Hiltunen, , ; Kaitera et al., , ), Vincetoxicum hirundinaria (Apocynaceae) supported fruiting and sporulation of C. flaccidum as expected. The other species of Scrophulariaceae tested, N. floribunda , was also moderately infected in the present experiment with both uredinia and telia formation.…”

“…Both of the tested species of Orobanchaceae, E. stricta and B. alpina , supported uredinia and telia production of C. flaccidum . Both of the tested species (Kaitera & Hiltunen, ; Kaitera et al., ) as well as several other species of Euphrasia , Pedicularis , Rhinanthus and Castilleja have been reported to be susceptible to C. flaccidum (Gäumann, ; Kaitera & Hiltunen, , ; Kaitera et al., , ; Klebahn, ). This indicates the high susceptibility of hemiparasites to C. flaccidum .…”

“…The rust spreads via species of Grossulariaceae ( Ribes ) and Orobanchaceae ( Pedicularis, Castilleja ) in North America and Asia (Kim et al., ; La & Yi, ; McDonald, Richardson, Zambino, Klopfenstein, & Kim, ; Mulvey & Hansen, ; Yokota & Uozumi, ; Yokota, Uozumi, Endo, & Matsuzaki, ; Zambino, ; Zhang et al., ). In Finland, C. ribicola has been shown to infect Asclepias, Bartsia, Castilleja, Loasa, Mentzelia, Pedicularis, Ribes and Tropaeolum after artificial inoculations (Kaitera & Hiltunen, , ; Kaitera, Hiltunen, & Hantula, ; Kaitera, Hiltunen, & Samils, ; Kaitera & Nuorteva, ).…”

“…In northern Fennoscandia, significant damage has been reported on Pinus sylvestris L. (Samils, Ihrmark, Kaitera, Hansson, & Barklund, ; Wulff et al., ). Cronartium flaccidum is able to sporulate on alternate hosts in genera Apocynum, Asclepias, Bartsia, Castilleja, Euphrasia, Gentiana , Grammatocarpus, Hyoscyamus, Impatiens, Loasa (Nasa), Melampyrum , Myrica, Nemesia, Nicotiana, Paeonia , Pedicularis, Rhinanthus, Saxifraga, Schizanthus, Swertia, Tropaeolum,Verbascum, Verbena, Veronica and Vincetoxicum (Gäumann, ; Hylander, Jørstad, & Nannfeldt, ; Kaitera & Hiltunen, , ; Kaitera, Seitamäki, Hantula, Jalkanen, & Kurkela, ; Kaitera et al., , ).…”

New genetic markers for identifying Cronartium flaccidum and Peridermium pini and examining genetic variation within and between lesions of Scots pine blister rust in Sweden

“…The aeciospores infect the alternate host, forming uredinia and urediniospores on the plant leaves. A number of plants have been reported as alternate hosts of C. flaccidum in Scandinavia within the genera Melampyrum, Loasa, Nemesia, Paeonia, Pedicularis, Tropaeolum, and Vincetoxicum (Kaitera et al 1999a;Kaitera & Hiltunen 2011). The rust spreads among and within the alternate hosts during the summer.…”