In the first stage of the project two major activities were carried out:

(1) the production of hybrid plants between cultivated potato and the wild species Solanum berthaultii and Solanum bulbocastanum, both reported in the literature to possess aphid resistance; and

(2) the screening of these parental and hybrid lines for aphid resistance

To make full use of the summer, we prioritized field testing of aphid resistance in the parental material. Preliminary results provided crucial insights: none of the tested lines of S. berthaultii or S. bulbocastanum showed measurable resistance to aphids. In contrast, S. chacoense - previously known for their resistance to the Colorado potato beetle - also demonstrated resistance to the aphid species Myzus persicae and Brachycaudus helichrysi.

These findings required an adjustment of our initial strategy regarding the choice of parental genotypes for hybridization. Originally, S. chacoense was included only as a control to assess hybridization efficiency and establish the baseline technological readiness level (TRL2). Based on the new results, S. chacoense will now be considered the primary source of insect-resistance genes with breeding potential, given its multi-insect resistance profile.

Regarding the somatic hybridization activity, the methodology for protoplast isolation, fusion, and culture has been established and will be applied, with minor adjustments as needed, to additional parental combinations (various local potato cultivars and the available S. chacoense lines). We also optimized several spectrophotometric biochemical assays, which represent an important part of the test battery required for the characterization of hybrids and are often associated with resistance to biotic stress factors.

The discovery of robust insect resistance under field conditions provides an excellent outlook for the project. It not only increases the likelihood of generating valuable breeding material that can be rapidly transferred to the beneficiary partner, but also opens the way for comprehensive studies on the mechanisms underlying resistance to different insect species.