sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDU Faculty of Forestry Journal
Serial: A, Number: Special Issue, Year: 2009, ISSN: 1302-7085, Page: 171-176
SEASONAL FRUITING AND SPORULATION OF THEKOPSORA AND
CHRYSOMYXA CONE RUSTS IN NORWAY SPRUCE CONES AND
ALTERNATE HOSTS IN FINLAND
Juha KAITERA 1* , E. TILLMAN-SUTELA 1 and A. KAUPPI 2
1 Finnish Forest Research Institute, Muhos Research Unit, FI-91500, Muhos, Finland. 2 University
of Oulu, Department of Biology, P.O. Box 3000, FI-90014 Oulu
ABSTRACT
*Juha.kaitera@metla.fi
Seasonal fruiting and sporulation of cone rusts were investigated in Norway spruce
cones and alternate hosts in 2006-2008. Current-year and one-year-old cones and leaves of
alternate hosts, Pyrola spp. and Orthilia secunda, were collected from case-stands in
southern and northern Finland bi-monthly or monthly and checked for rust fruitbodies.
Fruitbodies and different fruiting structures of the rusts were examined using light
microscopy (LM), and field emission scanning electron microscope (FESEM).
Spermogonia of Chrysomyxa pirolata and aecia of Thekopsora areolata developed
in current-year cones in June, while C. pirolata aecia developed and began to sporulate in
July. Thekopsora areolata aecia sporulated mainly in previous year’s cones in May-August.
Uredinia, telia and basidia of C. pirolata developed in overwintered Pyrola spp. and
Orthilia secunda leaves in May, and sporulated in May-June. Uredinia of T. areolata
developed in current-year P. padus leaves in June and sporulated in June-August. Telia of
T. areolata developed in late summer, but no basidia developed in overwintered P. padus
leaves in March-May.
Keywords: Cone rusts, Thekopsora areolata, Chrysomyxa pirolata, sporulation
1. INTRODUCTION
Good quality seed crops of Picea abies (L.) Karst. are irregular due to insects
and pathogens reducing both the amount and quality of seed crop in seed orchards
and natural forests throughout Finland (Kangas, 1940; Rummukainen, 1960;
Nikula and Jalkanen, 1990; Tillman-Sutela et al., 2004)). Thekopsora areolata (Fr.)
Magnus, and Chrysomyxa pirolata Wint., cause severe damage on Picea spp.
throughout the northern hemisphere (Savile, 1950; Gäumann, 1959; Roll-Hansen,
1965; Ziller, 1974). Thekopsora areolata infects Prunus spp. (Gäumann, 1959),
while C. pirolata infects species in genera Pyrola, Moneses and Orthilia (Savile,
1950; Gäumann, 1959; Ziller, 1974). Uredinia and telia develop on alternate hosts
after aeciospore infection.
In 2006, florescence and cone crop of Norway spruce were abundant, but due to
fungal injuries the seed crop was severely reduced in some seed orchards. The aim
of this study was to collect information of rust sporulation after a serious rust
outbreak to improve disease control. For a thorough description of the study, see
Kaitera et al. (2009).
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