Developing Genetically Engineered Resistance
to Potato Viruses

Potato (Solanum tuberosum) is one of the major food sources in the world. The crop, ranking fourth among all food crops, is affected by more than 20 different viral diseases. The most important viruses in Egypt are potato virus X (PVX), potato virus Y (PVY) and potato leaf roll virus (PLRV).

PVX and PVY depress potato tuber yield up to 80% and destroy the crop in combination with other potato viruses. These viruses are transmitted easily to a narrow range of hosts by sap and by several species of aphids in a non-persistent manner, whereas PLRV is transmitted by aphids in a persistent manner. The virus replicate tissue specifically in the phloem of the infected plants.

Traditional breeding did not, so far, succeed in providing a virus resistant potato plant. Genetic engineering and molecular biology techniques have great potential to improve plant cultivars by introducing genes of interest without perturbing the commercially desirable traits. Agrobacterium -mediated gene transfer techniques are available for potato cultivars.

OBJECTIVES

• Development of genetically engineered resistance to PVX, PVY, and PLRV by using strategies based on viral coat-protein expression in planta.

• Development and establishment of rapid and reliable virus indexing methods by using ELISA, dsRNA and PCR.

ACHIEVEMENTS

•  Establishment of a regeneration system for some commercial cultivars from leaf discs.

• Successful regeneration and transformation for two potato cultivars, with a chimeric gene encoding the coat-protein (CP) of PVX and PVY.

• Establishment of ELISA and PCR methods for detection of viruses.

in vitro potato regeneration & tuberization from leaf explant

transgenic potato plants