Susceptibility of different provenances of Pinus sylvestris, Pinus Contorta and Picea abies to Gremmeniella abietina

Abstract

In a randomized block factorial experiment, 1200 seedlings from four provenances, each of Pinus sylvestris, Pinus eontorta and Picea abies were inoculated with conidia (2 x lO'' and 1 x 10'' conidia/seedling) of Gremmeniella abietina {Bruncborstia pinea), isolated from P. eontorta plantations in northern Sweden. A further 600 seedlings were left as controls. The occurrence of symptoms and the extension of dead tissues on the annual shoots were recorded 13 months after inoculation. Only the higher spore dose resulted in significant infection. P. sylvestris and P. eontorta seedlings were equally susceptible (53% infected), and significandy more infected than P. abies secdlinsrs (39%). The annual shoots of P. sylvestris and P. abies were affected to 43% and 37% of their length, which was significantly more than 15% of the length oiP. eontorta shoots. The frequency of affected seedlings differed between the most southern and northern provenances of P. sylvestris and P. abies, and between the northwestern and the south-eastern provenance of P. eontorta. Twenty-six months after inoculation, a higher proportion of P. eontorta seedlings than P. sylvestris and P. abies seedlings had recovered, and a lower proportion of P. eontorta than P. sylvestris and P. abies seedlings had died. This paper discusses why P. sylvestris was found to be more susceptible to G. abietina than P. eontorta in this experiment, while the reverse is found in plantations in northern Sweden.

Resistance toGremmeniella abietina(European race, large tree type) in introducedPinus contortaand nativePinus sylvestrisin Sweden

“…However, infected P. contorta seedlings seemed more resistant in terms of survival rate, length of infected tissue, and recovery by production of new leaders. This is in accordance with earlier inoculation studies conducted in Britain (probably LTT) (Aitken 1993) and Sweden (STT) (Hansson 1998). In Hansson (1998), in situ inoculations caused significantly higher mortality and infection severity on P. sylvestris seedlings compared with P. contorta seedlings, even though the proportion of infected seedlings was equal between the two species.…”

“…This is in accordance with earlier inoculation studies conducted in Britain (probably LTT) (Aitken 1993) and Sweden (STT) (Hansson 1998). In Hansson (1998), in situ inoculations caused significantly higher mortality and infection severity on P. sylvestris seedlings compared with P. contorta seedlings, even though the proportion of infected seedlings was equal between the two species. The results in Hansson (1998) were surprising because field trials with pines 2-4 m in height (Hansson and Karlman 1997) and large-scale monitoring of pine plantations in northern Sweden with saplings 1-3 m in height (Karlman et al 1994) had found P. contorta to be more susceptible than P. sylvestris to STT G. abietina in terms of infection and mortality rates.…”

“…The results in Hansson (1998) were surprising because field trials with pines 2-4 m in height (Hansson and Karlman 1997) and large-scale monitoring of pine plantations in northern Sweden with saplings 1-3 m in height (Karlman et al 1994) had found P. contorta to be more susceptible than P. sylvestris to STT G. abietina in terms of infection and mortality rates. Hansson (1998) concluded that P. contorta and P. sylvestris may have the same ''genuine'' susceptibility to STT G. abietina, although the introduced P. contorta seem to be more affected by stress factors caused by extreme weather conditions.…”

Susceptibility of Pinus nigra and Cedrus libani to Turkish Gremmeniella abietina isolates

“…Susceptibility of conifers to G. abietina is to some degree under genetic control of the host (Roll-Hansen, 1972;Nevalainen and Uotila, 1984;Stephan et al 1984;Dietrichson and Solheim, 1987;Aitken, 1993;Hansson 1998;Sonesson et al, 2007). However, the role of environmental factors in disease development is essential; severe epidemics occur exclusively under environmental conditions which both predispose the host and favour the spread and survival of the fungus (Donaubauer, 1972;Petäistö and Kurkela, 1993).…”

Susceptibility of Polish provenances and families of pedunculate oak (Quercus robur L.) to colonisation by Phytophthora cambivora

“…For other forest trees, considerable amount of research in this range was performed on elms in reference to Ophiostoma novo-ulmi Brasier (Santini et al 2005) and on pines and spruces towards Gremmeniella abietina (Lagerb.) M. Morelet (Roll-Hansen 1971;Hansson 1998), and also inter alia to Cenangium ferruginosum Fr. (Kuzmina, Kuzmin 2008).…”