Fig 1.
Tuber and canopy morphology of two Hungarian potato cultivars, Hópehely (A and C) and White Lady (B and D).
Tubers were grown in field conditions (photography by Z. Polgár). The canopy morphology of the greenhouse-grown plants is shown. Four-week-old in vitro plants were potted and used for grafting experiments two weeks after potting. The arrows indicate the scion/stock junctions.
Fig 2.
Correlation between leaf size and tuberisation six weeks after grafting.
The area of the five largest leaves per plant was measured. Three consecutive experiments were carried out. In sum, 20–25 plants were tested in each experiment. HP, non-grafted control Hópehely; WL, non-grafted control White Lady; HP/HP, homo-grafted Hópehely; WL/WL, homo-grafted White Lady; HP/WL, hetero-graft: Hópehely scion/White Lady rootstock; WL/HP, hetero-graft: White Lady scion/Hópehely rootstock.
Fig 3.
PCA and VIP plots from PLS-DA showing the metabolite differences in the source leaves of non-grafted (A), homo-grafted (B and C) and hetero-grafted (D and E) plants. The VIP plots (F) indicate the major differences between each category. In each plot, the 95% confidence regions are displayed. The leaves were collected six weeks after grafting at four hours after sunrise. The data were obtained from two consecutive experiments with 3–4 groups of samples. Each group contained 3 leaf disks 1 cm in diameter cut from the middle of assimilating leaves of 3 individual plants. The labels are as in Fig 2.
Fig 4.
PCA and VIP plots from PLS-DA showing the metabolite differences in freshly harvested mature tubers of non-grafted (A), homo-grafted (B and C) and hetero-grafted (D and E) plants. The VIP plots (F) indicate the major differences between each category. In each plot, the 95% confidence regions are displayed. The tuber data were obtained from the same two consecutive experiments as those presented in Fig 3 for leaves. Each sample was prepared from 3 tubers approximately 1.5–2.0 cm in diameter. The data were obtained from 4–5 samples of each plant category. The labels are as in Fig 2.
Fig 5.
Differences in the galactinol and sucrose contents of leaves and tubers, respectively, detected by GC-MS; the relative data shown on the y axis are derived from a comparison of the peak sizes of the samples and an internal standard, ribitol.
The means were obtained from the data presented in S1 and S2 Tables. The standard deviations are indicated by the error bars. The means presented with the same letter are not significantly different at p ≤ 0.05 calculated by one-way ANOVA with post hoc Tukey HSD test. The labels of the x axis are as in Fig 2.