Potato virus X ( Rx1 and Rx2) in different potato genotypes]]>

摘要

Potato ( Solanum tuberosum L.) is considered as one of the most important staple foods in the world. Classical breeding for resistance to pests, pathogens and viruses involves the identification of resistance sources, which are often found in different wild potato species. Potato virus X (PVX) attacks potato worldwide, causing considerable amount of yield losses, reaching 20% of productivity depending upon the virus strain. To decrease its impact, there’s serious interest to develop new varieties carrying the Rx1 and/or Rx2 genes which originally came from the wild species Solanum tuberosum ssp. andigena and Solanum acaule, respectively; these genes are able to provide extreme resistance to PVX which could be facilitated with molecular marker-assisted selection. In this study, twenty-five potato genotypes, belong to Potato Research Center, were tested to detect the presence of Rx1 and Rx2 extreme resistance genes of PVX by using 5 Rx1 and 106 Rx2 specific markers, respectively, to enhance breeding efficiency for the purpose of developing new varieties. The results showed that three genotypes carried the 5 Rx1 marker. On the other hand, the results with the 106 Rx2 marker showed that thirteen individuals (52%) of the genotypes carried the 106 Rx2 marker. Sixteen genotypes (64%) are resistant to PVX and have a great potential for gene introgression, while the other nine genotypes were not carriers of the markers. Genotypes those are carrying the markers were strongly recommending to be used by breeders to develop new PVX extreme resistance potato varieties.