Mismatch repair deficiency increases the transfer of antibiosis and antixenosis properties against Colorado potato beetle in somatic hybrids of Solanum tuberosum + S. chacoense

BACKGROUND Colorado potato beetle ( CPB ) has become the biggest enemy of cultivated potato worldwide. One of the most effective sources of resistance to CPB is Solanum chacoense, an accession with a high leptine glycoalkaloid content. The aim of our study was to assay the repellence and toxicity of S. chacoense , its somatic hybrids ( SHs ) and their backcross progenies ( BC 1 ) with potato for CPB adults and larvae. Transgenic S. chacoense , deficient in DNA mismatch repair ( MMR ), was also used to produce SHs , in order to increase homeologous recombination and hence introgression of wild‐species DNA into the potato gene pool. RESULTS Wild‐type SH was highly resistant to CPB . Resistance to CPB of BC 1 progenies showed a 1:3 inheritance pattern. MMR ‐deficient SHs performed better in the resistance analysis. Most MMR ‐deficient SHs had a similar toxicity as S. chacoense and an intensely repellent effect on CPB adults. Resistance of SHs and BC 1 clones may be attributed to leptine biosynthesis, which was confirmed using a RAPD marker. CONCLUSION This is the first report of SHs and their progenies exhibiting both antibiosis and antixenosis against CPB . Resistant SHs are an important step forward in combating this voracious pest of potato. © 2016 Society of Chemical Industry