Figure 1:
Two weeks post-transplant, plant hosts were inoculated to evaluate their ability to host Stubby root nematodes (SRN) and Tobacco rattle virus (TRV). At month zero, test hosts were transplanted into pots containing viruliferous SRNs and cultured for one to three months. Each month a subset of hosts is sacrificed, nematode counts are taken, and a tobacco bait plant is transplanted into the test pot. After one month the tobacco bait plant is harvested and both foliar and root tissue was tested for the presence of TRV using RT-PCR.
Table 1.
Average nematode count, reproduction factor (Rf) values and proportion of foliage and root tissue samples with TRV infection at the final sampling time point.
| Plant | Experiment | Nematode count | Rf value | Foliage TRV infection (%) | Root TRV infection (%) |
|---|---|---|---|---|---|
| Alfalfa | 1 | 126.40b | 84.26b | 0a,b | 0b |
| Burbank | 1 | 20.00d | 13.33b | 33a,b | 50a,b |
| Castle | 1 | 119.87c | 79.91b | 0b | 0b |
| Tobacco | 1 | 720.80a | 480.53a | 80a | 100a |
| Alfalfa | 2 | 6.00d | 0.22c | 0b | 20a |
| Burbank | 2 | 64b | 2.41b | 100a | 100a |
| Castle | 2 | 19.6c | 0.73b,c | 0b | 0a |
| Tobacco | 2 | 768a | 28.98a | 100a | 80a |
1 Notes: Experiment 1 was inoculated 60 nematodes/pot, whereas Experiment 2 was inoculated using 1,060 nematodes/pot. The final measurement of Nematode count and Rf value was performed after three months. The final measurement of TRV infection in foliage and root tissues was performed after 4 months. a,b,c,dSuperscripted letter assignments (a-d) reflect groupings determined using Tukey’s honest significant difference within the experiment (α<0.05).
Figure 2:
Population counts of stubby root nematode, Paratrichodorus allius, across three months in pots grown with alfalfa, Russet Burbank potato, Castle Russet potato and tobacco; inoculated with 60 and 1,060 nematodes/10 L soil in Experiment 1 and 2, respectively.
Figure 3:
Number of bait plant tissue samples that tested positive and negative for the presence of TRV by RT-PCR. (A) Foliage tissue in Experiment 1 (B) Root tissue in Experiment 1 (C) Foliage tissue in Experiment 2 (D) Root tissue in Experiment 2.
Figure A1:
Nematode reproduction factor (Rf) estimates calculated from 250 cm3 soil samples collected from four plant genotypes, across three months, in two independent experiments. Individual data points are plotted as circular dots, whereas the population mean is plotted using an “X” symbol and standard error of the mean is denoted by the error bars. Experiments are differentiated by inoculation pressure. (A) Experiment 1 (60 nematodes/10 L) is plotted in orange (B) Experiment 2 (1,060 nematodes/10 L) plotted in red.
Figure A1:
(continued)