Table 1.
Consequences of MeJA treatment for nicotine and fitness measures
| Population | MeJA induced | Control | Difference | P |
|---|---|---|---|---|
| Nicotine concentration | ||||
| Plantation | 1.09 ± 0.04 | 0.71 ± 0.03 | 0.38 | 0.0006 |
| 1-yr burn (IB) | ||||
| (MeJA treatment) | 1.17 ± 0.07 | 0.91 ± 0.06 | 0.27 | 0.007 |
| (Leaf removal) | 1.35 ± 0.13 | 1.02 ± 0.08 | 0.33 | 0.009 |
| 1-yr burn (IA) | 0.95 ± 0.05 | 0.78 ± 0.04 | 0.17 | 0.0001 |
| 2-yr burn (IIA) | 0.95 ± 0.07 | 0.77 ± 0.09 | 0.19 | 0.012 |
| 2-yr burn (IIB) | 1.95 ± 0.13 | 1.29 ± 0.08 | 0.66 | <0.0001 |
| Capsules per plant | ||||
| Plantation | 36.1 ± 4.5 | 46.1 ± 5.5 | −9.9 | 0.0061 |
| 1-yr burn (IB) | ||||
| (MeJA treatment) | 113.6 ± 22.8 | 140.0 ± 26.7 | −24.2 | 0.04 |
| (Leaf removal) | 62.6 ± 7.7 | 85.6 ± 10.7 | −22.9 | 0.0001 |
| 1-yr burn (IA) | 62.3 ± 2.7 | 56.1 ± 2.7 | +6.2 | 0.0009 |
| 2-yr burn (IIA) | 8.0 ± 1.3 | 5.7 ± 1.0 | +2.8 | 0.15 |
| 2-yr burn (IIB) | 0 ± 0 | 0 ± 0 | 0 | 1.0 |
| Lifetime viable seeds per plant | ||||
| Plantation 100% | 4,494 ± 603 | 6,047 ± 634 | −1,550 | 0.0049 |
| 1-yr burn (IB) | ||||
| (MeJA treatment) 100% | ND | ND | ND | ND |
| (Leaf removal) 100% | 5,314 ± 796 | 7,335 ± 893 | −2,026 | 0.0005 |
| 1-yr burn (AI) 83% | 4,860 ± 208 | 4,505 ± 240 | 349 | 0.033 |
| 2-yr burn (IIA) 7.6% | 841 ± 131 | 538 ± 88 | 371 | 0.073 |
| 2-yr burn (IIB) 0% | 0 ± 0 | 0 ± 0 | 0 | 1.0 |
Mean (±1 SEM) nicotine concentrations, lifetime capsule, and viable seed production of MeJA-induced and control members of matched pairs of N. attenuata plants growing in a plantation population and four natural populations (listed in order of decreasing probability of survival to seed production) with the mean of differences between matched pairs (where + values indicate benefit and − values indicate cost of induction) and the P values for the differences as determined by paired t tests. By the lifetime viable seed data headings, the percentage of pairs that survived to produce seed are given. Nicotine concentrations were determined by HPLC analysis 9–10 days after the second MeJA treatment. Plantation values are of all above-ground parts, and all other values are of individual leaves from the same nodes from each member of the pair. Lifetime viable seeds were calculated as the product of each plant’s lifetime capsules per plant × average seeds per capsule × proportion of seeds that were viable. For the MeJA treatment of population IB, seeds per capsule data were available only for 56% of the pairs of plants that survived to produce seed, and lifetime viable seed production was not determined (ND) for this population. Percentage viable seed data were not determined for any of surviving plants of population IIA, and hence values presented are the lifetime seeds per plant. Percentage viable seed data were available for 201 of the 241 pairs of plants that survived to produce seed from population IA; the population mean (Table 2) was used for the 40 plant pairs with missing values to calculate the lifetime viable seed production values presented in Table 1 and Fig. 2.