Table 1.
Trial codes, trial year, number of test lines and types of sugarcane population screened for root-lesion nematodes (Pratylenchus zeae) for resistance from 2011 to 2020.
| Trial code | Year | Total | Remarks |
|---|---|---|---|
| WFLN19-01 | 2020 | 42 | Core breeding program |
| Nep18-1 | 2018 | 55 | Core breeding program |
| Nep17-1 | 2017 | 56 | Core breeding program |
| Nep16-1 | 2016 | 60 | Introgression population |
| Nep16-2 | 2016 | 86 | Introgression population |
| Nep14-1 | 2014 | 157 | Introgression population |
| Nep13-1 | 2013 | 153 | Introgression population |
| Nep12-1 | 2012 | 148 | Introgression population |
| Nep11-1 | 2011 | 118 | Introgression population |
| Total | 875 |
Table 2.
List of 15 sugarcane accession lines used in multiple trials with root biomass, and nematode resistance parameters.
| Accession | Type | No. of trialsa | Shoot biomass | Root biomass | Relative nematodes/plante | Relative nematodes/g root |
|---|---|---|---|---|---|---|
| IJ76-333 | Erianthus sp.b | 5 | 15.6abd | 46.7ab | 89.5f | 74.0c |
| IJ76-370 | Erianthus sp. | 4 | 10.3b | 53.8a | 88.0f | 67.3c |
| IJ76-388 | Erianthus sp. | 4 | 14.9ab | 41.3abc | 87.2f | 72.7c |
| KQ228 | Core | 7 | 17.8ab | 32.7abcd | 95.3cde | 91.2b |
| Q135c | Core | 9 | 16.1ab | 25cd | 100.6a | 101.8a |
| Q138 | Core | 6 | 15.9ab | 28.4bcd | 99.3abc | 98.7ab |
| Q183 | Core | 4 | 15.0ab | 24.6bcd | 101.1ab | 95.9ab |
| Q200 | Core | 7 | 15.5ab | 17.4d | 96.2bcd | 98.3ab |
| Q208ac | Core | 9 | 16.7ab | 28.4bcd | 99.3ab | 98.3ab |
| Q232 | Core | 7 | 21.1a | 28.9bcd | 94.3de | 90.5b |
| Q240 | Core | 5 | 17.9ab | 33.6abcd | 99.9abc | 94.3ab |
| Q245 | Core | 6 | 17.1ab | 26.6bcd | 99.4abc | 97.8ab |
| QBYC06-30376 | Introgression | 4 | 14.6ab | 30.9abcd | 92.1def | 87.5b |
| QBYC06-30390 | Introgression | 4 | 14.2ab | 20.3cd | 90.4ef | 89.6b |
| QBYN05-20563 | Introgression | 4 | 19.2ab | 21.6cd | 91.9def | 90.2b |
1 Notes: aNumber of trials the accession was included; bWild relative of sugarcane; cSusceptible controls; dMean of trials; means followed by same letter(s) in a column are not significant (p < 0.05) using Fisher’s protected least significant difference test; eRelativenematodes/plant or g root = T/S × 100, where T is mean nematodes per plant or g root for test accession line, and S is mean nematodes per plant or g root for two susceptible controls (Q208 and Q135).
Table 3.
Coefficient of variance (%) among shoot biomass, root biomass, number of nematodes per plant and number of nematodes per g of roots in each trial.
| Trial name | Shoot biomass | Root biomass | Nematodes/plant | Nematodes/g root |
|---|---|---|---|---|
| WFLN19-01 | 17.3 | 36.1 | 3.2 | 7.9 |
| Nep18-1 | 20.0 | 30.9 | 5.4 | 17.6 |
| Nep17-1 | 15.9 | 39.6 | 3.4 | 7.9 |
| Nep16-1 | – | 38.5 | 4.1 | 8.5 |
| Nep16-2 | – | 38.9 | 3.7 | 9.0 |
| Nep14-1 | 25.7 | 44.1 | 4.5 | 8.1 |
| Nep13-1 | 31.0 | 34.6 | 4.3 | 6.9 |
| Nep12-1 | 26.6 | 36.5 | 5.7 | 8.7 |
| Nep11-1 | 34.5 | 56.9 | 3.2 | 5.9 |
Table 4.
Pearson correlation coefficients among 15 accession lines to measure the repeatability among trials in relation to shoot and root biomass, and nematode resistance parameters.
| Trial | By Trial | No. accessions commona | Shoot biomass | Root biomass | Nematodes/plant | Nematode/g root |
|---|---|---|---|---|---|---|
| Nep11-1 | Nep12-1 | 8 | ‒0.15 | ‒0.52 | 0.45 | ‒0.01 |
| Nep11-1 | Nep13-1 | 7 | 0.36 | ‒0.84* | 0.78* | ‒0.35 |
| Nep11-1 | Nep14-1 | 8 | ‒0.17 | 0.19 | 0.33 | 0.38 |
| Nep11-1 | Nep16-2 | 8 | – | ‒0.24 | 0.38 | ‒0.53 |
| Nep11-1 | Nep17-1 | 6 | 0.56 | ‒0.69 | 0.57 | ‒0.52 |
| Nep11-1 | Nep18-1 | 8 | 0.51 | ‒0.11 | ‒0.1 | 0.45 |
| Nep11-1 | WFLN19-01 | 8 | 0.2 | ‒0.49 | ‒0.24 | ‒0.85** |
| Nep12-1 | Nep13-1 | 9 | 0.69* | 0.56 | 0.86** | 0.79** |
| Nep12-1 | Nep14-1 | 8 | 0.63 | 0.2 | 0.69 | 0.78* |
| Nep12-1 | Nep16-2 | 8 | – | 0.57 | 0.75* | 0.75* |
| Nep12-1 | Nep17-1 | 6 | 0.1 | 0.56 | 0.97*** | 0.95** |
| Nep12-1 | Nep18-1 | 8 | 0.52 | ‒0.5 | 0.7 | 0.59 |
| Nep12-1 | WFLN19-01 | 8 | 0.13 | 0.86** | 0.7 | 0.77* |
| Nep13-1 | Nep14-1 | 9 | 0.28 | 0.27 | 0.51 | 0.51 |
| Nep13-1 | Nep16-2 | 7 | – | 0.56 | 0.9** | 0.74 |
| Nep13-1 | Nep17-1 | 5 | 0.12 | 0.2 | 0.89* | 0.72 |
| Nep13-1 | Nep18-1 | 6 | 0.25 | 0 | 0.42 | 0.12 |
| Nep13-1 | WFLN19-01 | 6 | 0.63 | 0.47 | 0.45 | 0.44 |
| Nep14-1 | Nep16-2 | 9 | – | 0.86** | 0.58 | 0.6 |
| Nep14-1 | Nep17-1 | 6 | 0.25 | 0.47 | 0.47 | 0.38 |
| Nep14-1 | Nep18-1 | 6 | 0.8 | 0.75 | 0.42 | 0.56 |
| Nep14-1 | WFLN19-01 | 7 | 0.13 | 0.61 | 0.4 | 0.01 |
| Nep16-2 | Nep17-1 | 7 | – | 0.72 | 0.91** | 0.93** |
| Nep16-2 | Nep18-1 | 8 | – | 0.3 | ‒0.02 | ‒0.1 |
| Nep16-2 | WFLN19-01 | 9 | – | 0.64 | 0.38 | 0.29 |
| Nep17-1 | Nep18-1 | 8 | 0.68 | 0.28 | 0.82* | 0.75* |
| Nep17-1 | WFLN19-01 | 9 | 0.58 | 0.81** | 0.87** | 0.85** |
| Nep18-1 | WFLN19-01 | 10 | 0.09 | 0.16 | 0.89** | 0.71* |
Table 5.
Pearson correlation coefficients to compare the relationship of number of root-lesion nematodes per plant and number of nematodes per g of roots with shoot biomass and root biomass.
| Nematodes/plant | Nematodes/g roots | |||
|---|---|---|---|---|
| Trial name | Shoot biomass1 | Root biomass | Shoot biomass | Root biomass |
| WFLN19-01 | 0.53** | ‒0.07 ns | 0.21 ns | ‒0.86*** |
| Nep18-1 | ‒0.04 ns | ‒0.09 ns | ‒0.31* | ‒0.60*** |
| Nep17-1 | ‒0.03 ns | ‒0.36* | ‒0.07 ns | ‒0.81*** |
| Nep16-1 | – | ‒0.0009 ns | – | ‒0.51*** |
| Nep16-2 | – | ‒0.06 ns | – | ‒0.65*** |
| Nep14-1 | 0.40*** | 0.17* | ‒0.26** | ‒0.61*** |
| Nep13-1 | 0.06 ns | 0.13 ns | ‒0.27** | ‒0.50*** |
| Nep12-1 | 0.25* | 0.24* | 0.01 ns | ‒0.29** |
| Nep11-1 | ‒0.13 ns | 0.27* | ‒0.23* | ‒0.63*** |
Figure 1:
Regressions to show the relationship between root biomass and log (nematodes per g of roots) in nine nematode trials.
Figure 2:
Regressions to show the relationship between shoot biomass and log (nematodes per g of roots) in seven nematode trials.