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Figure 1:
Examples of root-knot nematode gall ratings for sugarcane based on percentage of root system with galls. 1 = ≤1 to 2%, 2 = 2 to 25%, 3 = 25 to 50%, 4 = 51 to 75%, 5 ≥ 75% (modified from Shepherd 1979).
Figure 2:
Regressions to show the relationship between root biomass and ln(eggs per g roots+1) in eight nematode trials.
Pearson correlation coefficients among 22 accession lines to measure the repeatability among trials in relation to nematode (Meloidogyne javanica) resistance parameters.
Trial
by Trial
No. of accession linesa
Eggs per plantb
Eggs per g root
Gall rating
Nem12-1
Nem13-1
6
0.99***
0.89*
0.92**
Nem12-1
Nem13-2
6
0.98***
0.94**
0.86*
Nem12-1
Nem15-1
6
0.10 ns
0.20 ns
0.56 ns
Nem12-1
Nem16-2
7
0.98***
0.76*
0.20 ns
Nem12-1
Nem17-1
6
0.94**
0.95**
0.86*
Nem12-1
Nem18-1
8
0.93**
0.63 ns
0.64 ns
Nem12-1
Nem19-1
8
0.87**
0.92**
0.86**
Nem13-1
Nem13-2
3
0.99 ns
0.82 ns
–
Nem13-1
Nem15-1
12
0.47 ns
0.31 ns
0.27 ns
Nem13-1
Nem16-2
12
0.92***
0.10 ns
0.35 ns
Nem13-1
Nem17-1
10
0.74*
0.60 ns
0.72*
Nem13-1
Nem18-1
8
0.91**
0.71*
0.82*
Nem13-1
Nem19-1
7
0.69 ns
0.59 ns
0.89**
Nem13-2
Nem15-1
5
−0.02 ns
0.33 ns
0.71 ns
Nem13-2
Nem16-2
6
0.95**
0.80 ns
−0.30 ns
Nem13-2
Nem17-1
5
0.92*
0.95*
0.68 ns
Nem13-2
Nem18-1
6
0.90*
0.46 ns
0.68 ns
Nem13-2
Nem19-1
6
0.86*
0.83*
0.87*
Nem15-1
Nem16-2
18
0.19 ns
0.29 ns
−0.30 ns
Nem15-1
Nem17-1
15
0.25 ns
0.12 ns
0.19 ns
Nem15-1
Nem18-1
10
0.51 ns
0.66*
0.16 ns
Nem15-1
Nem19-1
13
0.66*
0.60*
-0.48 ns
Nem16-2
Nem17-1
14
0.74**
0.28 ns
0.06 ns
Nem16-2
Nem18-1
10
0.81 ns
0.63*
−0.38 ns
Nem16-2
Nem19-1
12
0.43 ns
0.40 ns
0.27 ns
Nem17-1
Nem18-1
8
0.97***
0.77*
0.82**
Nem17-1
Nem19-1
13
0.92***
0.86***
0.79**
Nem18-1
Nem19-1
10
0.93***
0.71*
0.88**
Pearson correlation coefficients to compare relationships of nematode (Meloidogyne javanica) resistance parameters with sugarcane shoot biomass and root biomass.
Eggs per plant
Eggs per g root
Visual rating
Trial name
Shoot biomass
Root biomass
Shoot biomass
Root biomass
Shoot biomass
Root biomass
Nem19-1
−0.08 nsa
−0.27 ns
−0.47**
−0.74***
−0.14 ns
−0.41**
Nem18-1
0.01 ns
−0.03 ns
−0.36**
−0.45**
0.01 ns
−0.08 ns
Nem17-1
0.070 ns
−0.26 ns
−0.42**
−0.65***
−0.004 ns
−0.26 ns
Nem16-2
–
0.13 ns
–
−0.44***
–
0.11 ns
Nem15-1
−0.093 ns
−0.07 ns
−0.24**
−0.28**
−0.19 ns
−0.12 ns
Nem13-1
0.15 ns
0.14 ns
0.12 ns
−0.06 ns
0.30**
0.21*
Nem13-2
0.19 ns
0.02 ns
0.08 ns
−0.19*
−0.10 ns
−0.40***
Nem12-1
0.18 ns
0.06 ns
−0.02 ns
−0.23**
0.24*
−0.04 ns
Trial names, trial year, number of accession lines and types of sugarcane populations screened for root-knot nematode (Meloidogyne javanica) resistance from 2012 to 2019.
Trial name
Trial year
Number of accession lines
Source
Nem19-1
2019
42
Core breeding program
Nem18-1
2018
56
Core breeding program
Nem17-1
2017
56
Core breeding program
Nem16-2
2016
95
Introgression population
Nem15-1
2015
112
Introgression population
Nem13-1
2013
138
Introgression population
Nem13-2
2013
155
Introgression population
Nem12-1
2012
148
Introgression population
Total accession lines
–
802
–
Coefficient of variance (%) among shoot biomass, root biomass, visual ratings, number of eggs per plant and number of eggs per g of roots in each trial.
Trial name
Shoot biomass
Root biomass
Visual rating
Eggs per plant
Eggs per g root
Nem19-1
21.5
36.3
20.5
2.3
6.4
Nem18-1
20.7
38.7
19.3
2.8
3.2
Nem17-1
27.3
48.7
20.5
2.7
9.9
Nem16-2
-
38.2
22.1
6.0
8.7
Nem15-1
20.9
38.3
30.0
9.2
11.9
Nem13-1
21.5
29.6
22.4
28.6
47.1
Nem13-2
27.9
37.0
22.6
25.3
27.8
Nem12-1
24.0
37.5
29.3
25.0
25.5
List of 22 sugarcane accession lines used in multiple trials with root biomass, and nematode resistance parameters.