Agriculture Reference
In-Depth Information
greater than zero and estimate the narrow-sense
heritability from the regression equation.
How would the relationship between the regres-
sion and the narrow-sense heritability differ if the
regression were carried out between only the male
parent and the offspring?
(5) Four types of diallel can be analyzed using
Griffing's Analysis. Describe these types. Fam-
ilies from a 5
V
r
W
r
1
98.0
102.0
2
66.3
53.2
3
161.8
207.4
4
50.3
65.2
5
71.4
83.1
×
5 half diallel (including selfs)
were planted in a two replicate yield trial at a
single location. The parents used in the diallel
design were chosen to be the highest yielding lines
grown in the Pacific-Northwest region. Data for
yield were analyzed using a Griffing's Analysis of
variance. Family means, averaged over two repli-
cates, degrees of freedom and sum of squares (SS)
from that analysis are shown below. Explain the
results from the Griffing's Analysis. What differ-
ences would there be in your analytical methods
if the parents used had been chosen at random.
=
=
Mean of
V
r
89.56;
Mean of
W
r
V
r
W
r
=
=
102.19;
7702.01:
15192.05;
=
10 535.29. From these data, test
whether the additive-dominance model is ade-
quate to describe variation between the progenies.
What can be determined about the importance
of additive compared to dominance genetic vari-
ation in this study. From all the results (Griffing
and Hayman and Jinks, above) which two par-
ents would you use in your breeding programme
and why?
(6) Two genetically different homozygous lines of
canola (
B
.
napus
L.) were crossed to produce
F
1
seed. Plants from the F
1
family were self-
pollinated to produce F
2
seed. A properly designed
experiment was carried out involving both parents
(P
1
and P
2
, 10 plants each), the F
1
(10 plants)
and the F
2
families (64 plants) and was grown in
the field. Plant height of individual plants (cm)
recorded after flowering. The following are family
means, variances and number of plants observed
for each family.
V
r
W
r
Parent 1
Parent 1
62.0
Parent 2
Parent 2
71.0
69.5
Parent 3
Parent 3
55.5
52.5
50.5
Parent 4
Parent 4
72.5
80.5
56.5
76.5
Parent 5
Parent 5
70.5
66.5
36.5
71.0
64.5
Source
d.f.
SS
Family
Mean
Variance
Number of
plants
GCA
4
6694.058
SCA
10
825.676
Replicates
1
8.533
P
1
162
1.97
10
Error
14
317.467
P
2
121
2.69
10
F
1
149
3.14
10
Total
29
7845.733
F
2
139
10.69
34
From the same diallel data (above), within
array variances (
V
r
) and between array and non-
recurrent parent covariances (
W
r
) were calculated.
The values of
V
r
and
W
r
for each parent along with
the of mean of
V
r
, mean of
W
r
, sum of squares if
V
r
(
Complete a statistical test to determine
whether an additive-dominance model of inher-
itance is appropriate to adequately explain the
inheritance of plant height in canola. If the
additive-dominance model is inadequate, list
three factors that could cause the lack of fit of
the model.
V
r
W
r
)
, sum of squares of
W
r
(
)
and sum
of products
V
r
W
r
are shown below.
