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.
Published by
Industrial Forestry Association Tree Improvement Laboratory 135 Nisqually Cut-of( Road, S. E. Olympia, Washington 98503
No. 43
December 1982
MONITORING ROOT ROTS
The appearance of black stain fungus (Verticicladiella wagneri) on two test plots
has led to an attempt to monitor root rots as part of the data collected.
The first detection was on the Starker Forests Gershman Plantation of the Burnt
Woods Cooperative in 1979 where black stain disease was identified in 9 dead trees.
At the
By 1982 infection in the same disease center had spread to 26 trees.
Champion International Silver Panther Plot of the Gold Beach Cooperative the disease
was first detected in 1981, and is now found in several spots in the northeast
quadrant of the plot.
Infected trees die 1 or 2 seasons after the first symptoms
appear.
Undoubtedly many more centers of this and other root rots will be detected
on the more than 500 test sites now scheduled in the region.
If root rot centers
are detected on your plots please call Roy Silen (503) 757-4339.
A visit to the
plot by a pathologist will be arranged.
In order to monitor the appearance and spread of the various root rots we have added
appropriate numbers to the "Instructions for Use of Progeny Tree Measurements
These involve
Record Form" to provide for plot measurements at 5-year intervals.
columns 44-45.
Numbers 13, 14, and 15 will be assigned to mortality from black
stain, laminated (Poria) and Armillaria root rots, respectively.
The combination
of plot visits by pathologists on first detection, and regular 5-year records of
spread should provide landowners a fairly precise estimate of the impact of these
root rots in their plantations.
Regionwide,. these records can become the best
available data both for management and research on the spread rate of these rots.
HOW TO START
Joe Wheat, IFA
The initiation of programs through the classical selection of plus trees has been
officially
Region.
frowned upon since 1966 by some forest geneticists in the Douglas Fir
We now have 15-year data from an open-pollinated progeny test showing no
significant differences in height between families from Number
1, 2, and random
parents.
On the other hand, differences between families within or between groups
are great.
Thus, we encourage early progeny testing of a large number of initial
selections.
Better Tree_s
Throµgh Genetics
Page 4
annually improve the graft compatibility of the seed lots sent out as new test
results come in from the field.
It appears that we will have another big pollination
program this coming spring so the seed shortage which has plagued us in the past
appears to be over.
Any organization with seed, seedling, or cutting requests should sent those requests
to me prior to the first of the year so I can make a fair allocation.
lift cuttings and seedlings shortly after the first of the year.
problem with cuttings last year appears to have been solved;
We normally
Our survival
no difficulties are
expected this winter.
FULL-SIB AND CLONAL SEED ORCHARDS
Roy Silen, PNW
Many of the Progressive Tree Improvement Programs are now involved with choice of seed
orchard type.
This item covers only a comparison between clonal and full sib seedl­
ing orchard in terms of genetic gain.
There are many other considerations in the
choice of orchard such as relative total costs, seed production history, genetic
diversity of the seed, flexibility and practicability.
For some landowners the
dominant concern in the choice is simply that their mature parent trees are too large
for field crossing.
The genetic gain in growth rate from both options needs to be clarified not so much
as a basis for choosing one over the other, but to understand what is involved in
maximizing returns under whichever option is chosen.
It turns out that under the
same assumptions, gains from additive genetic variation initially are about the same.
The additive component appears to account for most of the genetic variation.
The main
gain difference between the two hinges on opportunities for selection following
orchard establishment.
The simplest illustration of the features of the computation of gain involves a
mating of three males with three different females.
We assume that the six produce
Say that two
offspring averaging 100 units (for example, decimeters at 10 years).
of the parents test out to average 110-unit progeny, two average 100-unit progeny,
and two average 90-unit progeny.
parents 1, 2,
A factorial box of family average height with
and 3 as females and 4,
5,
and 6 as males illustrates this:
M A L E s
F
4
5
6
E
M
A
L
Family
Gain or
average
loss
1
120
110 100
110
2
110
100
90
100
3
100
90
80
90
110
100
90
100
0
genetic merit,
(plus any maternal
-10 ''''
effects)
of the
+''
''' '·'''
parent
E
Family Average
s
Gain or loss
Estimates of
the
genetic merit of the
male parent
I
'
,· ,
Page 6
The same opportunity exists to upgrade the full-sib orchard with rogueing of
families, and the gain with the same parent complement would average about the
same as with rogueing of clonal orchards.
One additional opportunity for upgrading exists in the full-sib orchards.
involves within-family selection.
This
Although only half the additive genetic
variance is between families, the other half is within families.
The potential
exists for nearly doubling the gain over family selection alone in the full-sib
orchard.
In terms of the above example, average orchard seed could range between
120 units and 140 units, depending on effectiveness of selection.
There is difficulty in capturing large gains from within-family selection in
seed orchards.
Phenotypic selection methods would have to be effective, juveaile­
mature correlations appreciable, gene-environment interactions small, and inbreeding
among family members low.
Still, any effective within-family selection would be
so rewarding as to suggest that no opportunity is lost in any selection done as the
full-sib orchard is thinned to its final spacing.
Thus it would pay to carry large family numbers as long as possible, to provide
selection potential and to improve juvenile-mature correlations.
Merit is seen
in the recent suggestions by seed orchardists to plant full-sib family blocks
from which selections would be moved by tree spade to permanent orchard positions.
Scoring criteria should be improved with better genetic parameters of desired
traits.
Fortunately gene-environment interactions for height growth at family level
have been fairly low in tests up to 15 years when such within-family selection
would be made in seed orchards.
And minimal inbreeding could be encouraged with
appropriate spacing of related individuals.
Even for traits of moderate or low
heritabilities, but with high portions of additive genetic variation, like growth,
the opportunity to capture some of the within-family gain seems good.
The kind of orchard initially chosen by an organization should not be considered
as a permanent fixture.
By the time any Progressive Program is a decade old, steps
should already be taken that lead to replacement with a better one.
Better is
usually thought of in the sense of more genetic gain for growth.
There are many
routes to this goal once breeding begins.
But in a complex environment like the
Douglas-fir region, the goals of seed orchards
will be complex to fit both
adaptation needs, and the level of long-term commitment of the landowner to
intensive management.
Better future orchards may be far more complex in
parentage and design than one dictated simply by maximizing genetic gain.
Even so,
a general understanding of genetic gain principles should be basic for everyone in
the tree improvement programs.
AN EVALUATION OF AERIAL CONE HARVESTING ON THE SHELTON RANGER DISTRICT, OLYMPIC NATIONAL FOREST, IN 1982 Clyde Rau,
USFS
INTRODUCTION
Preliminary cone crop surveys in June of 1982 indicated heavy male and female
flowering on Pacific silver fir and western hemlock at 3 ,000 feet above sea