Producing more improved Norway spruce seeds - what can research offer? Katri Himanen Natural Resources Institute Finland katri.himanen@luke.fi 1.12.2018

The need for improved seed is continuous kg Source: Evira

The need for improved seed is continuous Source: Skogsstyrelsen

Norway spruce – a species with a challenging reproductive biology and ecology Matures at the age of 25–35 years: A challenge for both tree breeding and seed production. Norway spruce is a masting tree species Abundant cone crops 1–2 times in a decade The masting is a way for the species to avoid cone and seed predation The best quality seed crops with the highest genetic diversity are collected in years of abundant flowering Cone and seed pests, including cone rusts (namely Thekopsora areolata) can distroy entire cone crops.

Ways to increase seed production and yield in seed orchards Increasing flowering The frequency The abundance The starting age of the flowering, retaining the productivity Ensuring pollination and thus increasing seed yield Supplemental mass pollination Increasing the movement of pollen in the seed orchard Protecting the seed crop from insects and rusts Proper collecting timing and methods for seed extraction

Increasing flowering

Increasing flowering

Increasing flowering

Increasing pollination Sauramo, M. 1940: Suomen luonnon kehitys jääkaudesta nykyaikaan.

Increasing pollination   Seed quality class  Tree 1 2 3 4 5 6 7 Tree effect, P-value Full, % 29.2 56.4 60.3 56.7 84.5 86.4 64.7 <0.001 Empty, % 59.3 35.2 29.5 24.1 9.9 8.0 32.8    Seed quality class  Clone E11 E246 E252 E456D E1549 Clone effect, P-value Full, % 63.8 63.9 79.2 79.1 33.2 <0.001 Empty, % 25.7 20.7 8.6 14.6 52.0 Himanen, K., Helenius, P., Ylioja, T. & Nygren M. 2016. Intracone variation explains most of the variance in Picea abies seed weight: implications for seed sorting. Canadian Journal of Forest Research 46: 470−477.

Protection of the cone and seed crop Spruce seed moth (Cydia strobilella) damaged seed Biological control agent including the bacteria Bacillus thuringiensis spp. Aizawai x kurstaki (Turex 50 WP) registered for the control of spruce cone worm (Dioryctria abietella) and cloaked pug (Eupithecia abietaria )

Controlling Thekopsora areolata damage Pesticide use has proven unsuccessful Does eradicating the alternate host Prunus padus help and do possibly other alternative hosts exist? The role of insects in disease development in T. areolata epidemics?

Do we loose viable seed in seed sorting? Nurseries prefer seed lots with high germinability, purity and homogenous size and weight Homogenous seed weight helps in the functioning of the sowing machines and helps in creating an evensized seedling crops Thus, the smallest and largest seeds are sorted from the marketed seed lots.

Seeds with weight of 5,35–7,35 mg included Seed loss 32% 36% 26% 14% 22% Average full seed weight 6,35 mg Seed weight, mg Loss of full seed 25,4% Clone in seed orchard

Seeds with weight 4,35–8,35 mg included Seed loss 4,3% 5,0% 0,8% 1,1% 1,9% Seed weight, mg Loss of full seed 2,4% Clone in seed orchard

Developing Norway spruce seed production Metsäpuiden siementuotannon kehittäminen. For years 2018–2019 https://www.luke.fi/projektit/mesike/ The aim is to increase the availability of high-quality Norway spruce seed orchard seed trough smart and intensive management regimes. New methods are developed to increase the flowering of Norway spruce grafts, to enhance pollination of female flowers, to protect the developing cones and seeds against insects and to increase seed yield by improving cone collection timing and seed extraction. The project is conducted in collaboration with Siemen Forelia Oy and Tapio Silva Oy.

Controlling Thekopsora areolata damage Tandem Forest Value funding for a two year joint project by Åke Olson, SLU, and Juha Kaitera, Luke. Production of healthy Norway spruce seeds: host specificity, pathogenicity and infection biology of Thekopsora areolata. 1) the importance of eradication of the alternate host Prunus padus and possibly other alternative host plants to reduce T. areolata infection, 2) the importance of insects in disease development and for the high genetic diversity of T. areolata in epidemics, and 3) spreading effectiveness of rust spores from Prunus host to the surroundings.

Conclusions The need for improved Norway spruce seed is expected to remain stable in the near future. The acceptability of rotation-based forestry creates uncertanty. The biological characteristics of Norway spruce make seed production challenging, but we are not without tools to increase yields. Being familiar with the biology and ecology of both spruce and its pests is key to find solutions to the problems with seed production. As new management tools are developed and used, new problems may arrise: does increasing flowering frequency increase pest damages?

Conclusions Research in increasing flowering, controlling pests, improving pollination and in reducing seed loss in processing is needed and can help to bring more improved seed to the market. In the changing climate, ensuring a high – or controlled – level of genetic diversity in forest reproductive material is important. The effects of the production steps of seeds to genetic diversity of the seed lots are not under full control. We can do better. Nordic collaboration exists and is a useful approach to solving the problems in Norway spruce seed production.