Citrullus lanatus (Thunb.) Matsum. & Nakai - Cucurbit Breeding ...

z Data are ratings from four families of resistant PI accessions by susceptible cultivars of Citrullus lanatus
var. lanatus and citroides. Disease assessment scale adopted for evaluating watermelon for resistance to
gummy stem blight: 0 = no disease; 1 = yellowing on leaves (suspect of disease only); 2 to 4 = symptoms
on leaves only; 5 = some leaves dead, no symptoms on stem,; 6 to 8 = symptoms on leaves and stems; 9 =
plant dead
2
y k ! h ! " n
2 ( P)
x
w
µ ( P ) ! µ P " 1.5 ! 2 " b
a
µ F ( ) ! µ ( P )
1
a
µ ( P ) ! µ ( P ) b
a
" 1 ! µ F / )
# ( ) ! µ P 1
a
0 +
$
%
1 *
µ ( P ) ! µ P b
a
8 " 5 2
2
5 ( P ) + 5 a ( F ) ! 2
2 ( P ) + 2 " 5 b
2
/
[ ( F ) 1 ] 2
0
4
[ ( ) ] 2
8 " # 2 $
%
&
( ) !
F 2
1
[ ] 2
µ ( P ) ! µ ( P )
b
a
2
# ( P ) + # a
2 ( P ) + 2 " # b
2 [ ( F ) 1 ] '
(
4
)
v Negative estimate from a negative estimate of additive variance
u F 2 Bartlett's χ 2 = 1.94; P-value = 0.16
t F 2 Bartlett's χ 2 = 0.01; P-value = 0.92
s F 2 Bartlett's χ 2 = 1.49; P-value = 0.22
r F 2 Bartlett's χ 2 = 2.95; P-value = 0.09
3
4
( )
( )
& , 2
'
( . 3
-4
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