Figure 5.

A, Flowering behavior of grafted potato wild-type plants under LD conditions when grafted with StSUT4-RNAi plants. Early flowering is also observed in wild-type plants if grafted with StSUT4-RNAi plants, depending on the presence of source leaves at the rootstock. B, Schematic representation of graft experiments. Plants were regenerated from tubers and grafted after development of the first six leaves. Graft experiments were repeated twice with potato ‘Désirée’ with six reciprocal grafts from each transgenic line per experiment. C, Tuber yield of grafted StSUT4-RNAi potato plants (subsp. tuberosum) grafted on potato wild-type plants (subsp. andigena), which do not tuberize under LD conditions. Plants were grafted when they have four to five leaves and were kept under LD conditions. As a control, transgenic plants were grafted on their own rootstock (right, StSUT4-RNAi₈₁ grafted on StSUT4-RNAi₈₁ and StSUT4-RNAi₁₀ grafted on StSUT4-RNAi₁₀) and potato subsp. tuberosum wild type was grafted on potato subsp. andigena, which did not lead to tuber production (left, wild-type tuberosum grafted on wild-type andigena). sd is given. andig, andigena; tuberos, tuberosum.