Transcript Towards efficient breeding

Efficient long-term
cycling strategy
DaDa work 2001-2003
Contents of 1 h
Introduction and our studies (5 min.)
Main finding (2 min)
Testing strategy: optimization and timing
(50 min):
Single-stage strategies compared,
Two-stage strategies compared,
Amplified case: Progeny testing versus
Pheno/Progeny.
Main finding separately for pine and spruce
(5 min.)
The Road to this semianr
Seminar 2004.03.02
4: BP size
optimised
3: Ph/Prog amplified
(pine), effect of J-M.
Hungry shark
1-2: Best testing
strategy
Breeding
cycler
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Main findings: cloning is the best strategy
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Main findings
•Clonal test is superior (use for spruce)
•Progeny testing not efficient
•For Pine, use 2 stage Pheno/Progeny
•Pine flowers not needed before age ~ 1015
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
General M&M
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Basic advantage of our approach
Is a complete comparison as it simultaneously
considers:
Cost
Gain per
time
Diversity
Other things,
e.g. to well
see the road
The long-term program
Recurrent cycles of mating, testing and balanced selection
Adaptive
Mating
environment
Within
family
selection
Breeding
population
Testing
We consider one such breeding population
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Benefit = Group Merit/Year
Diversity loss was set to be as important as gain
Gain
Diversity
Time
Main inputs and scenarios
Low
Main
High
Genetic parameters
lower typical for higher
Time components reasonable Pine or reasonable
bound
spruce
bound
Cost components
While testing an alternative parameter value,
the other parameters were at main scenario
values
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
The time and cost explained
•Cost per test plant = 1 ’cost unit’, all the other costs
expressed as ratio of this 1.
•Such expression also helped to set the budget
constraint corresponding to the present-day budget
Production of Cutting of
sibs (4 years) ramets
Crossing
Genotype
Recombination
depend. cost=2
cost=20,
(per ortet)
Time=4
Mating time
Established in
5 years after
seed harvest
Rooting of
ramets (1 year)
Transportation
Nursery
Establishment,
maintenance and
assessments
Field trial
Plant dependent cost=1 (per ramet)
Time before
Testing time Lag
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
All these costs should fit to a
present-day budget
Budget estimate is taken from pine and spruce
breeding plan ~ test size expressed per year and BP
member.
~ 10 ’cost units’ for pine, 20- for spruce.
ng of
Rooti year)
s (1
ramet
of
tting
f Cu mets
o
n
o
i
ra
d u ct
Pro
rs)
4 yea
sibs (
type
sing
Geno st=0.1
Cros
ation epend. co t)
mbin
d
o rt e
Reco 20-50,
(per
cost= =3
Time
time
g
n
i
t
Ma
Field
p or
Trans
ery
Nurs
ent,
lishm
Estab ance and
en
maint sments
asses
in
lished
Estab s after
r
5 yea rvest
ha
d
e
e
s
d
Plant
e
befor
e
m
i
T
tation
epen
e r ra
t=1 (p
s
o
c
t
den
trial
met)
e Lag
m
i
t
ng
Testi
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Why budget constraint per BP
member and year?
• Because costs expressed per BP member
= easier to handle
• Gain efficiency should be assessed per
unit of time
• Optimization= optimum combination of
testing time and testing size to obtain max
GM/Year and to satisfy the budget
constraint (use Solver)
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
The Relativity theory holds for
the Cycler as well… It optimizes
“your case”
What if budget is such
What if costs are such
What if we reduce them
What if heritably is such
What if J-M correlation is
So, interpretation should
consider that everything is
relative to each other
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Single-stage
testing
strategies
Objective: compare strategies based on
phenotype, clone or progeny testing
Clone or progeny testing
Phenotype testing
N=50
N=50
(…n)
(…n)
(…n)
OBS: Further result on
numbers and costs- for one of
these families
(…n)
(…m)(…m)(…m) (…m)(…m)(…m)
(…n), (…m) and selection age were optimized
Parameters- for reference
Parameters
Main scenario
Alternative scenarios
Additive variance (sA2 )
1
Dominance variance, % of the additive variance in BP (sD2)
25
0; 100
Narrow-sense heritability (h2) (obtained by changing sE2)
0.1
0.05; 0.5
Additive standard deviation at mature age (sAm), %
10
5; 20
Diversity loss per cycle, %
0.5
0.25;1
Rotation age, years
60
10; 120
1 (phenotype)
3; 5 (phenotype)
5 (clone)
3; 7 (clone)
17 (progeny)
5; 7 (progeny)
30
15; 50
0.1 (clone),
1; 5 (clone),
1 (progeny)
0.1; 5 (progeny)
Cost per plant (Cp), $
1
0.5; 3
Cost per year and parent (constraint)
10
5; 20
Time before establishment of the selection test (TBEFORE), years
Recombination cost (CRECOMB), $
Cost per genotype (Cg), $
Group Merit Gain per year (GMG/Y)
To be maximized
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
CVa at mature age
• CVa=14 % is based on pine tests in south
Sweden Jansson et al (1998),
• 1/2 of additive var in pop is within full sib
families,
• Our program is balanced= gain only from
within full-sib selection,
• Thus, CVa within fam= CVa in pop divided
by the square root of 2, thus a CV = 10%,
which we use here (even if not quite
correct). CVa within = sqrt(s /2)= sqrt(s )/sqrt(2)= s /sqrt(2)
2
2
2
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Test 26 clones with 21 ramet
(18/15  budget), select at age 20
Test 182 phenotypes; select at
age 15, ( budget: 86, for 17
years) (second best)
Test 11 female parents with 47
progeny each; select at age 34 (
budget: 8/34, 40 years)
Annual Group Merit, %
Results-clonal best, progeny worst
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Clone
Phenotype
Progeny
0 0.1 0.2 0.3 0.4 0.5 0.6
Narrow-sense heritability
At all the scenarios, Clonal was
superior, except high h2.
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
GM/Y digits after comma are important
• If for Clone GM/Y=0.25%; cycle= 30
years then
• Cycle GM=8 % (gain 8.5 - 0.5 div loss)
• Thus GM/Y reduction by 0.03 (10%) =
Cycle gain reduction by 1%
• Loss of Cycle gain by 1% = important
loss
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
How flat are the optima (clone)?
h2=0.1, lower budget, at optimum testing time
Less ramets at optimum
clone number is sensitive:
no > than 5, (not shown)
If problems with cloning,
better-> clones with <
ramets
0.30
Optimum 18(15)
Annual Group Merit , %
Clone number (ramet per
clone) = 12(22)-24 (14)
0.25
0.20
GM/Y by Pheno
0.15
0.10
4(59) 10(25) 15(18) 20(14) 30(10) 40(8)
If h2 is higher , see next
Clone no (ramets per clone)
Test time 17
18
20
22
23
25
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
If not enough cuttings, better more clones with less ramets,
rather than to reduce ramet number at optimum clone number
testing
time
70(5)
57(6)
50(7)
45(8)
39(9)
32(11)
30(12)
28(13)
26(14)
24(15)
22(16)
21(18)
20(18)
19(19)
0.450
0.440 0.436
0.430
0.420
0.410
This line marks loss of GM/Y > 0,03
0.400
0.390
0.380
GM/Y by Phenotype=0,275
0.370
0.360
0.350 Variation in these outlined numbers will
0.340 not cause marked loss of benefit
0.330
36(10)
Budget=20, h2=0.1, Cycling cost=20, time 4, Tbefore=5, Cg=2, J-M corr by L(2001), c=100
Optimum for clone number (ramet no per clone)
12 12 12 12 12 13 13 13
14 14 15 15 15 15 17
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Higher
2
h
= more clones and
less ramets
Clone no/ramet no
0.50
0.40
GM/Y, %
Optimum then is
between 18/15 and
30/10
46/5
18/15
0.30
0.20
Spruce plan 40/15
0.10
Ola’s thesis, paper I, Fig.
9= 40 cl with 7 ram at test
size 280
0.00
28/9
13/23
0
0.1
0.2
0.3
0.4
0.5
Narrow-sense heritability
Budget= 10
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
The optimal testing time 18-20
•These 18-20 years
with conservative
J-M function
(Lambeth 1980)
•With Lambeth
2001, about 15-17
years
0.30
Annual Group Merit, %
•No effect to test
longer than 18-20
years
Clone strategy
0.25
0.20
0.15
0.10
0.05
0.00
15 16 17 18 19 20 21 22 23 24 25
Testing time, years
Figure with optimum at main scenario parameters (budget=10) clones/ramets 18/15
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
How realistic are the optima?
• Optima depends on budget, h2, J-M
correlation- how realistic are they?
1. Budget is the present-day allocation.
Increase will result in more gain. But we test
how to optimise the resources we have.
2. h2 =0,1 seems to be reasonable
3. J-M functions taken from southerly pines, it
affects the timing with stand. error of 2
years (7-10-12).
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Why Phenotype ≥Progeny ?
• Drawbacks of Progeny: long time and high
cost (important to consider for improvement)
• Phenotype generates less gain but this is
compensated by cheaper and faster cycles.
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Dominance would
not markedly affect
superior
performance of
clonal testing
Annual Group Merit, %
Dominance seems to matter little
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Clone
Phenotype
Progeny
0
25 50 75 100 125
Dominance variance (% of
additive)
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
0.30
0.25
0.30
0.25 Tbefore
On Genotype cost
Clone
0.20
0.20
0.15
Clone
Progeny
0.15
Progeny
0.10
0.10
Phenotype
0.05
0.05
0 1 2 3 4 5
Cost per genotype
6
0 3 6 9 12 15 18
Delay before establishment of
selection test (years)
Expensive genotypes are of interest only if it would
markedly shorten T before for Progeny or improve cloning
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Recombinatin cost and total budget
Annual Group Merit , %
0.3
0.30
Clone
Clone
0.25
Phenotype
0.2
0.20
Phenotype
0.15
0.1
Progeny
Progeny
0.10
0.0
0.05
0
5
10
15
20
Budget per year and parent
25
10
20
30
40
50
60
Recombination cost
Important factors; what happens if they fluctuate?
Phenotype get more attractive at low budget, strategy
choice not depending on recombination cost
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Conclusions
• Clonal testing is the best breeding strategy
• Phenotype 2nd best, except very low h2 or high
budget
• Superiority of the Phenotype over Progeny is
minor = additional considerations may be
important (idea of a two-stage strategy).
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Let’s do it in 2
stages?
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Phenotype/Progeny strategy
Mating
Stage1: Phenotype
test and pre-selection
Reselection
based on
performance of
the progeny
Stage 2:.Sexual
propagation of
pre-selected
individuals
Testing of
the progeny
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Values- study 2
Parameters
Main scenario
Additive variance (sA2 )
Dominance variance, % of the additive variance in
2
BP (sD )
Environmental variance, % of total variance s
( E2 )
Additive standard deviation at mature age(sAm), %
Diversity loss per cycle, %
Rotation age, years
1
Alternative
scenarios
-
25
0; 100
Time before establishment of the selection test
(TBEFORE), years
Recombination cost (CRECOMB ), $
Cost per genotype (Cg), $
Cost per plant (Cp), $
Budget per year and parent (the constraint)
Group Merit Gain per year (GMG/Y)
88
0; 38; 94
10
5; 20
0.5
0.25;1; 5
60
10; 20; 120
1 (phenotype)
3; 5 (phenotype)
5 (clone;
3; 7 (clone;
phenotype/clone) phenotype/clone)
17 (progeny;
5; 7 (progeny;
phenotype/progeny) phenotype/progeny)
30
0.1 (clone),
1; 5 (clone),
1 (progeny)
0.1; 5 (progeny)
1
0.5; 3
10
5; 20; 50
To be maximized
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Results: two-stage 2nd best
•Clone = Phenotype/Clone
= no need for 2 stages.
0.30
Clone
0.25
•Phenotype/Progeny is 2nd 0.20
best = best for Pine
•If Progeny initiated early,
may~ Phenotype/Progeny
= need for a amplification
•Phenotype/Progeny is shown with
a restriction for Phenotype
selection age > 15
Pheno/Progeny
0.15
Phenotype
Progeny
0.10
1
3 5
7
9 11 13 15 17
Delay before establishment of
selection test (years)
arrows show main scenario
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
If budget is cut
by half = simple
Phenotype test
Annual Group Merit, %
Budget cuts = switching to
Phenotype tests in Pine
0.3
Clone
Pheno/Progeny
0.2
Phenotype
Progeny
0.1
0
5
10
15
20
Budget per year and parent (%)
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Budget cuts for Pheno/Progeny
Genetic gain, %
Budget =
resources
reallocated on
cheaper
Phenotype test
5
32
Stage 2 Progeny
4
17
3
5(44)
Stage 1
5(72)
Phenotype
2
Budget=10
Budget=5
Testing time 10 (stage 1) and 14 (stage 2) little affected by
the budget
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Why Pheno/Progeny was so good?
• It generated extra gain by taking advantage
of the time before the candidates reach
their sexual maturity
• This was more beneficial than single-stage
Progeny test at a very early age
• Question for the next study: is there any
feasible case where Progeny can be
better?
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Progeny test with and without
phenotypic pre-selection
• Is there any realistic situation where
Progeny testing is superior over
Pheno/Progeny (reasonable interactions and
scenarios)
• What and how flat is the optimum age of
pre-selection for Pheno/Progeny? (when do
we will need flowers?)
Phenotype test
Pre-selection
age?
Progeny test
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Simply- where best to invest?
Phenotypebased preselection
Early
flowering
induction
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Time and cost components
CPer CYCLE = Crecomb + n (CG + m CP),
Tcycle = Trecomb + TMATING + TLAG + Tprogtest
TMATING age of sufficient flowering capacity to initiate
progeny test (for 2-stage strategy it corresponds to the age
of phenotypic pre-selection
TLAG is crossing lag for progeny test (polycross, seed maturation,
seedling production)
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Parameters study 3
Main scenario
values
Alternative
scenario values*
Interactive
scenario values
Additive variance (sA2 )
1
-
-
Dominance variance, % of the additive variance
(sD2)
25
0; 100
-
Narrow-sense heritability (h2) (obtained by
changing sE2)
0.1
0.01; 0.5
0.01
Additive standard deviation at mature age %
10
-
-
Diversity loss per cycle, %
0.5
-
-
L (2001)
L(1980); G(2000)
L(1980)
3 to 25 by 1
-
-
Crossing lag for progeny test (crossing; seed
maturation, seedling production),years
3
5; 8
-
Rotation age (RA), years
50
20; 30; 80
80
Recombination cost (CRECOMB), $
30
0; 100
-
Cost per genotype (Cg), $
1
0.1; 10
-
Cost per plant (Cp), $
1
0.1; 2
-
Budget per year and parent, $ (the constraint)
10
5; 20
-
Parameters
J-M genetic correlation function
Age of mating for progeny test (age of sufficient
flowering capacity for progeny testing), years
Annual progress in Group Merit (GM/Y)
1
To be maximized
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
J-M correlation functions
•
•Gwaze et al. (2000)=
genetic correlations from 19
trials with 190 fams of P
taeda western USA.
•Lambeth (1980)= phenotypic
fam mean corrs from many
trials of 3 temperate conifers
J-M genetic correlation coefficient
•Lambeth (2001) Main =
genetic corrs in 4 series (15
trials) P taeda (296 fams)
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Lambeth (1980)
Lambeth & Dill (2001)
Gwaze et al. (2000)
0.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Ratio selection/rotation age (Q)
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
• 2 stage strategy
was better under
most reasonable
values
•No marked loss
would occur if
mating is postponed
to age 15
Annual Group Merit (%)
Results: 2 stage is better
Main scenario
0.6
Pheno/Progeny
0.3
Progeny
0.0
0
5 10 15 20 25
Age of mating for progeny
test (years)
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
J-M correlation affects pre-selection age
•The gain generating
efficiency mainly depends
on slope of J-M correlation
function.
•
1.0
J-M genetic correlation coefficient
•Optimum selection age
depends on efficiency of
Phenotype to generate
enough gain to motivate
prolongation of testing for
an unit of time.
0.9
0.8
10
0.7
0.6
0.5
0.4
0.3
0.2
0.1
7
Gain would increase
faster if switching to
12 progeny test
Gain increases
fast by time
Lambeth (1980)
Lambeth & Dill (2001)
Gwaze et al. (2000)
0.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Ratio selection/rotation age (Q)
Do we have J-M estimates for spruce and pine?
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
When the loss from optimum is
important?
Annual Group Merit (%)
When early testing is advantageous
Rotation age = 20
0.6
2
0.8
h = 0.5
Plant cost= 0.1
0.6
Pheno/Progeny
0.6
0.4
0.3
0.3
0.0
0.0
Progeny
0.2
0.0
0
5 10 15 20 25
0
5 10 15 20 25
0
5 10 15 20 25
Age of mating for progeny test (years)
h2 is high but then
Phenotype alone is
better
Rotation is short
Plants are cheap
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Annual Group Merit (%)
Better crossings are motivated
Crossing lag= 5
0.5
0.4
0.4
Pheno/Progeny
10; 0.26
0.3
0.2
0.23
Progeny
0.3
0.1
0.0
0.0
5 10 15 20 25
10; 0.25
0.22
0.2
0.1
0
Crossing lag= 8
0.5
0
5 10 15 20 25
Age of mating for progeny test (years)
Crossing lag and genotype costs had no marked effect
= the crosses can be made over a longer time to
simultaneously test all pre-selected individuals and
their flowering may be induced at a higher cost.
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
These are as for our
interactive scenario:
•low heritability (0,01),
•long rotation (80 y)=
less J-M at pre-selection,
•weak J-M correlation
(L1980)
Annual Group Merit (%)
Progeny is motivated when
conditions disfavour Phenotype
Interactive scenario
0.06
Pheno/Progeny
Progeny
0.03
0.00
0
5 10 15 20 25
Age of mating for progeny test
(years)
But the optima flat and scenario unrealistic
Optimum test time and size for pine
(for one of the 50 full sib fams)
Cycle time~ 27
Gain=8 %
GM/Y= 0,27%
Select back the
best of 5 when
progeny- test
age is 10
Stage 2. Progenytest each of those 5
with 30 offspring
2-4 years, at a high
cost if feasible
Mating
Long-term
breeding
Lag- 3-4
years
Stage 1: Test
70 full-sibs
Select 5 at age 10
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
What if no pine flowers until age 25?
•Progeny is the last
•Budget cuts, high h2 will
favour Phenotype
0.15
0.179
0.135
0.140
Phenotype
•Phenotype with selection age
of 25 is better
0.20
Progeny
•Pheno/Progeny is still leading
Annual Group Merit, %
This means, singe stage Phenotype cycle time > 25
years and For the two-stage, pre-selection not at its
Main (h=0.1, budget=10), Flowers at age 25
optimum age (10 years)
0.10
0.05
0.00
Pheno/
Progeny
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
May be 2 cycles of Phenotype
instead of Pheno/Progeny?
Phenotype
Cycle, GM/year, GM/cycle 2 cycle s
years %
of Pheno
20
0,152
3,04
6,08
Pheno/Prog 40
0,181
Answer is No: 7,26 is > 6,08
7,26
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Conclusions
•Under all realistic values, Pheno/Progeny
better than Progeny
•Sufficient flowering of pine at age 10 is
desirable, but the disadvantage to wait until
the age of 15 years was minor,
•If rotation short, h2 high, testing cheap,
delays from optimum age could be
important
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Our main findings
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Main findings- spruce
Clonal test by far the best
If higher h2
more clones
less ramets
Present plans:
size 40/15,
selection age:
10 years
(18)
(18)
Select at age 15
(20) depending on
J-M correlation
(15) (15) (15) (15) (15) (15)
With L(2001), Cycle time~ 21 Gain=8.2 % GM/Y=
0,34%
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Main findings- Pine
Use 2 stage Pheno/Progeny strategy
(70)
(70)
(30) (30)(30)(30)(30) (30) (30)(30)(30)(30)
Stage 1 Phenotype
select at age 10 (15
only 3% GM lost)
Stage 2 Progeny
test select at ca 10
With L(2001), Cycle time~ 27 Gain=8 % GM/Y=
0,27%
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Research needs- Faster cloning
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
Research needs (a PhD thesis)
•Faster, better cloning: embryogenesis, rooting,
C-effects (especially for pine)
•Sufficient flowering at age 10 (15) for pine
•Documentation of flowering in breeding stock
•How sexual maturation, flowering abundance
are related to breeding value?
Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15
In breeding, thanks to Dag there may
be less risk to enter a wrong way ...
The end