Genetic Stability and Agronomic Performance of Transgenic Potato (Solanum tuberosum L.) cv. IPB CP1 Overexpressing FBPase and ClRan1 Genes Across Three Generations

Potato (Solanum tuberosum L.) is an essential crop in Indonesia, yet domestic productivity continues to lag behind rising consumption. The FBPase gene encodes the FBPase enzyme involved in sucrose biosynthesis, whereas the ClRan1gene regulates mitotic cell division; co-expressing these genes offers a promising strategy to enhance yield potential. This study evaluated the genetic stability, gene expression, physiological and morphological responses, as well as yield performance of transgenic IPB CP1 potatoes overexpressing FBPase and ClRan1 genes across three generations (G0, G1, and G2). Using a randomized complete block design, four transgenic clones (C1FB1–C1FB4) were evaluated alongside a non-transgenic control. Transgene integration was verified by PCR, transcript expression was quantified by RT-qPCR, and photosynthetic parameters, including photosynthetic rate, stomatal conductance, and intercellular CO2 concentration, were measured using a LI-COR LI-6400XT system. PCR analysis confirmed the stable integration of both transgenes in all transgenic clones across all generations. Gene expression was detected in all generations, stabilizing in G1 and G2 following transient silencing in G0. Transgenic clones exhibited significantly higher photosynthetic rates and stomatal conductance, accompanied by increased root length and total biomass. Consequently, tuber weight and number were significantly greater in G1 and G2 relative to the non-transgenic control. These findings demonstrate that the combined overexpression of FBPase and ClRan1 in IPB CP1 potato enhanced physiological efficiency and yield potential. Among the evaluated lines, clone C1FB4 showed the highest transgene expression level and superior agronomic performance, highlighting its promise as a candidate line for improving national potato productivity.