[Objectives] In present work, the effect of ABA synthetic gene StiNCED2 on potato tuber formation and the possible mechanisms were investigated to explore the potential genes for improving potato tuber yields. [Methods] The expression levels of AHA synthetic genes StNCEDl and StNCED2 were analyzed by semi-quantitative KT-PCK assay to identify the main gene in tuber formation. Transgenic lines overexpressing StNCED2 were constructed and obtained by genetic engineering and transformation. FCK-based molecular identification and ABA content determination verified the positive lines. The potato tubers of selected T1 and '17 lines with control were collected by two-season field planting to analyze the yields. QKT-PCK assays analyzed the expression changes of genes involved in ABA signaling, GA synthesis and metabolism, GA signaling in transgenic lines T1, T7 and control. [Results] StNCED1 expressed in initial stolon and elongated stolon, but not in swollen stolon, initial tuber and mature tuber while StNCED)2 expressed in the whole process of tuber formation, and the highest expression was found in elongated stolon, which was selected for further study. StNCED)2 overexpression lines Tl and '17 had higher expression levels of StNCED)2 and more ABA contents than the control. By planting Tl, '17 and control lines in two seasons, potato yield analysis showed that overexpressing StiNCED2 can promote tuber yield due to the increase of single potato tuber weight, not the tuber number. QKT-PCK assay showed that ABA signaling transcription factor St AH El and GA metabolism gene StGA2oxl were up-regulated while GA synthetic genes StGA3ox2, StGA20oxl and GA signaling transcription factor GAMYH were down-regulated in stolon and tubers of overexpression lines, suggesting there might be a direct interaction between ABA and GA. [Conclusions] ABA synthetic gene StNCED2 can promote tuber formation and is a potential gene for increasing potato yield by genetic engineering.[Objectives] In present work, the effect of ABA synthetic gene Sti\CED2 on potato tuber formation and the possible mechanisms were investigated to explore the potential genes for improving potato tuber yields. [Methods] The expression levels of AHA synthetic genes Sti\CEDl and StSCED2 were analyzed by semi-quantitative KT-PCK assay to identify the main gene in tuber formation. Transgenic lines overexpressing StNCED2 were constructed and obtained by genetic engineering and transformation. FCK-based molecular identification and ABA content determination verified the positive lines. The potato tubers of selected T1 and '17 lines with control were collected by two-season field planting to analyze the yields. QKT-PCK assays analyzed the expression changes of genes involved in ABA signaling, GA synthesis and metabolism, GA signaling in transgenic lines T1, T7 and control. [Results] StNCED1 expressed in initial stolon and elongated stolon, but not in swollen stolon, initial tuber and mature tuber while StNCED)2 expressed in the whole process of tuber formation, and the highest expression was found in elongated stolon, which was selected for further study. StNCED)2 overexpression lines T1 and '17 had higher expression levels of StNCED)2 and more ABA contents than the control. By planting T1, '17 and control lines in two seasons, potato yield analysis showed that overexpressing StNCED2 can promote tuber yield due to the increase of single potato tuber weight, not the tuber number. QKT-PCK assay showed that ABA signaling transcription factor St AH El and GA metabolism gene StGA2oxl were up-regulated while GA synthetic genes StGA3ox2, StGA20oxl and GA signaling transcription factor GAMYH were down-regulated in stolon and tubers of overexpression lines, suggesting there might be a direct interaction between ABA and GA. [Conclusions] ABA synthetic gene StNCED2 can promote tuber formation and is a potential gene for increasing potato yield by genetic engineering. [ABSTRACT FROM AUTHOR]