Managing a model population to market the potential of breeding

Tree breeding characteristics Model population

• Goals• Techniques

Breeding strategies• Standard• Model• Combined

Advantages/disadvantages

Bengt Andersson, SkogForsk, Box 3, SE-918 21 Sävar, Sweden

Breeding of forest trees

Long generation intervals

Low genetic gain per time

Postponed return from breeding investments

Breeding populations for - increased yield - climatic change prep. - gene conservation

Ph

oto

peri

od

(lat

itud

e)

Temperature climate (growing season days)

Model population

Primary goals Shorten generation time to 1/3 Unchanged gain Unchanged diversity

Operational size 19 selected parent trees (50 normally) 20 full-sib families (50 normally) 760 candidate trees (500 normally)

Model population- components

Exclude time lag for sexual maturity• Vegetative propagation• Clonal testing

Early tests for evaluation/selection• NIR (Near InfraRed reflection) for hardiness• MI (Mitotic Index) for growth • Field performance for 2nd stage selection

Early flowering for generation turnover• Top-grafting with young scions• Accelerated growth of selected individuals

Model population- components

Exclude time lag for sexual maturity• Vegetative propagation• Clonal testing

Early tests for evaluation/selection• NIR (Near Infrared Reflection) for hardiness• MI (Mitotic Index) for growth • Field performance for 2nd stage selection

Early flowering for generation turnover• Top-grafting with young scions• Accelerated growth of selected individuals

80

90

100

110

120

60 70 80

survival (%)

he

igth

(re

lati

ve

)

Fig. Breeding values (BLUPs) of 13 Scots pine clones,based on progeny performance in field trials. (Andersson)

superior

average

0

1

2

3

4

5

6

7

Julian day

MI

Fig 5. Mitotic index from pooled data from , superior clones (AC 1066, AC 2011 and

AC 3023) and average clones (AC 1011, AC 1013 and AC 2053) between Julian

day 115 (April 25th) and 297 (October 24th). Vertical bars represent standard errors.

Fig. Mitotic index (MI) from pooled superior () and average ()clones between April 25 and Oct. 24. (Sundblad et al.)

Fig. Predicted damage (Near Infra Red reflection - NIR) and observed damage after freezing (Electrolytic Conductivity - EC), of Scots pine seedlings from latitude 53-67. (Sundblad et al.)

Predicted damage (NIR)

Ob

serv

ed d

ama

ge

(EC

)

Top-grafting for early flowering

0 2 12 15 25 Year

0 2 12 15 25 Year

50 P

, dpm

500

F1ca

ndid

ates

pc

20.0

00 F

2pr

ogen

y tr

ials

eval

uati

on F

2

sele

ctio

n50

F1,

dpm

50 P

, dpm

sele

ctio

n50

F1,

dpm

earl

y te

stev

alua

tion

8

veg.

pro

p.

500

x 10

top-

graf

ting

4

Standard strategy

Model strategy

0

50 P

, dpm

Year

Combined strategy - an example

2

50 x

40

F1 c

andi

date

s

veg.

pro

p.

2000

x 1

0(to

p-gr

aftin

g)

4 8

earl

y te

stev

alua

tion,

(top-

graf

ting)

,

tran

spla

ntin

g to

fiel

d

pri

mar

y se

lect

ion

50 x

4 F

1, d

pm

200

x 10

F2

can

dida

tes10

veg.

pro

p.20

00 x

10

12 16

earl

y te

stev

alua

tion,

field

test

eva

luat

ion

final

, com

bine

d

inde

x se

lect

ion

100

x 2

F2

Model population- concluding remarks

Strong points• Substantial time reduction possible• Techniques seem promising• Each activity independent of others

Weak points• Techniques still need development• Selections based on early tests • Culling (vegetative prop., early flowering)