Eila TillmanSutela, Anu Hilli and Anneli Kauppi

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Arctic Circle
Rovaniemi
Oulu
Muhos
Helsinki
Germination changes of Picea abies seeds at
water-based pretreatments

• Eila Tillman-Sutela, Anu Hilli and Anneli Kauppi
• Finnish Forest Research Institute and University
  of Oulu

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INTRODUCTION
Pretreatments are a prerequisite for a mechanized
seedling production in modern forest tree
nurseries. The goal is to achieve a homogenous
seed lot - germination capacity and rate of at
least 95 . Seed extraction is only the first
step in a multi-phased procedure preceding
sowing.
Conifer species have a high genetic control over
germination attributes and their differences
between and within species. Structural
differences in the seed coat and nucellus cause
functional differences between moistened spruce
and pine seeds. Results of ecological studies
suggest that pretreatment conditions should be
customized for different seed species. Highly
mechanized treatments tend to be homogenized
using water and elevated temperatures to
accelerate the process. Pretreatments of spruce
seeds have been reduced to a minimum due to
unpredictable results.
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• The aim of our study was to find out
• changes in the germination attributes of Norway
  spruce seeds during the multi-phased pretreatment
  chain,
• impact of seed structures on the changes of
  germination attributes from cone collection to
  storage
• effect of storage on germination attributes of
  IDS-treated spruce seeds.

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MATERIAL AND METHODS
1200 l of cones collected in February
2001 Extraction
using water 580 l
in airflow 20 ºC 40 l, control
without water 580 l
by hand, 20 cones
38 ºC

• De-winging
• Water cleaning
• Drying
• Mechanical cleaning
• Storage 90 d, -3 ºC

• Radiography
• Germination tests,
• ISTA
• Moisture content measurements
• Floating tests
• Microscopy
• Tukeys multiple comparison test
• paired t-test

• IDS-treatment
• Moistening, 20 ºC, 16 h
• Incubation, 5 ºC, 24 h
• Desiccation, 20 ºC
• Separation
• 11 fractions
• Drying, 20 ºC
• Storage, -18 ºC
• ---------------------------
• 11 phases

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Changes in germination parameters of
dry-extracted spruce seeds at different
pretreatment phases
Changes in germination parameters of
water-extracted spruce seeds at different
pretreatment phases
Germination
Germination rate
IDS
1 Initial germination
8 Initial moistening
2 Extraction
9 Incubation 24 h, 5 ºC
3 Dewinging
10 Desiccation 45 min
4 Water cleaning
11 Storage drying Fr 1
5 Drying
12 - "- Fr 2
6 Mechanical cleaning
13 - "- Fr 3
14 - "- Fr 4 -10
7 Storage 90 d, -3 ºC
15 -"- Fr 11
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Opened seed coat in a moistened fungi-infected
spruce seed.
Opened micropyle of the seed coat in a moistened
spruce seed.
Spruce
Large nucellar cap covers about ¾ of the length
of the micropylar end of the spruce seed.
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Germination capacity
2001
2002

Germination rate
2001
2002
100
-01
80
-02
60
40
20
0
-01
-02
-01 -02
-01 -02
-01 -02
-01 -02
1
2
3
4-10
11
Fr
The changes of germination parameters in
dry-extracted, IDS-treated seed fractions after
one years storing at 18 ?C
Germination capacity
2001
2002
Germination rate

2001
2002
100
80
-01
60
-02
40
20
0
-01 -02
-01 -02
-01 -02
-01 -02
-01 -02
1
2
3
4-10
11
Fr
The changes of germination parameters in
water-extracted, IDS-treated seed fractions after
one years storing at 18 ?C
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CONCLUSIONS

• Separation of spruce seeds succeeded well
  according to the principles of the IDS-method,
  even if the germination parameters in the
• fungi-infected seed lot did not reach 95 .
• The result was achieved using a surprisingly
• short incubation time compared to the
• experiences in pine seeds.
• Short incubation time may be favourable to Norway
  spruce seeds because of the rapid opening of the
  seed coat in moistened seeds.
• Restriction of water and lowering of temperature
• at least at the extraction phase of
  winter-collected spruce cones should be
  considered.
• The results need verification using good quality
  seeds collected in consecutive months.

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Cone collection
Seed extraction
Water cleaning
De-winging
Storage
Mechanical cleaning
Sowing
Storage
Drying
PREVAC
  IDS
(Incubation Desiccation Separation

Storage drying)
Sowing in nurseries
Pretreatment of forest tree seeds from cone
collection to nursery sowing