Wei Huang, Jie Zheng, Bihua Nie, Jiana Li, Ruhao Chen, Xianzhou Nie, Zhen Tu, Kyle Gardner, Jiaru Chen, Manhua Yang, Jingcai Li, Jianke Dong, Hui Ma & Botao Song

Theoretical and Applied Genetics; August 2024; vol.137; article 198

Figure: Potato virus A symptom.

Key message

The Ra extreme resistance against potato virus A was mapped to the upper of chromosome 4 in tetraploid potato.

Abstract

Potato virus A (PVA) is one of the major viruses affecting potato worldwide and can cause serious disease symptoms and yield losses. Previously, we determined that potato cultivar Barbara harbors Ry_sto (genotype: Ryryryry) and Ra (genotype: Rararara) that each independently confer extreme resistance to PVA. In this study, employing a combination of next-generation sequencing and bulked-segregant analysis, we further located this novel Ra on chromosome 4 using a tetraploid BC₁ potato population derived from a Ry-free progeny (Rararararyryryry) of Barbara (RarararaRyryryry) × F58050 (rararararyryryry). Using 29 insertion–deletion (InDel) markers spanning chromosome 4, Ra was delimited by the InDel markers M8-83 and M10-8 within a genetic interval of 1.46 cM, corresponding to a 1.86-Mb genomic region in the potato DM reference genome. The InDel marker M10-8, which is closely linked with the resistance against PVA in the Ry-free segregating populations, was then used to screen 43 selected Ry_sto-free tetraploid potato breeding clones. The phenotype to PVA was significantly correlated with the present/absent of the marker, albeit with a 9.3% false positive rate and a 14.0% false negative rate. These findings are of importance in furthering the cloning of Ra and employing the marker-assisted selection for PVA resistance.

See https://link.springer.com/article/10.1007/s00122-024-04705-x