[01] Adane Gebeyehu, Plant Biotechnology Program; National Agricultural Biotechnology Research Centre, Holeta, Ethiopia.

The present study was conducted to investigate combining ability of multiple resistance genes to achieve durable resistance against potato late blight (Phytophtora infestans) through cisgenesis and transgenesis approaches. In this study, both cisgenesis and transgenesis approaches were followed to introduce different combinations of potato late blight R genes. Six constructs containing combinations of late blight R genes were transformed to the potato variety Desiree using Agrobacterium tumefaciens mediated transformation and a bacterial kanamycin resistance selection marker (NPTII). The construct Rpi-blb2:R8 had the lowest transformation efficiency while R8: Rpi-edn2 had the highest transformation efficiency followed by R8: Rpi-sto1. Functionality tests in the previously transformed marker free and marker-assisted transformation events were also done using the agro infiltration assay and detached leaf assay as well as transfer-DNA (T-DNA) and vector back bone integration by using PCR. Most of the transgenic events were also evaluated in the field for their resistance against P. infestans.

Cisgenesis, Late Blight, Marker-Free Transformation, Resistance Gene, Transgenesis

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