Bacterial wilt caused by Ralstonia solanacearum is the main bacterial disease in potato. Solanum commersonii Dun. (cmm; 2n = 2x = 24, 1 EBN) is a native species to southern Brazil, Uruguay and Argentina with desirable traits for introgressive hybridisation breeding into cultivated potato such as resistance to R. solanacearum. In Uruguay, successful crosses between cmm and Solanum tuberosum Group Tuberosum (tbr; 2n = 4x = 48, 4 EBN) have been carried out with this objective, resulting in backcross 1, 2 and 3 progenies. The aim of this study was to characterise one backcross 3 progeny (BC₃) using cytogenetic, genetic, morphological and agronomic descriptors. Resistance to R. solanacearum showed transgressive segregation and an association with plant architecture. Fifty-two percent of individuals had chromosome numbers close to cultivated potato with no evidence of preferential loss of cmm chromosomes. All BC₃ individuals showed male sterility, probably due to nuclear-cytoplasmic interactions. Although there was wide segregation in morphological traits, most individuals resembled the recurrent tbr parents. A few more backcrosses combined with screening for bacterial wilt resistance may be necessary to allow for further recombination and removal of undesirable traits from cmm. The presence of BC₃ individuals with chromosome numbers close to 2n = 48, combining morphological traits from tbr with good levels of resistance, suggests the occurrence of introgression events. This points to S. commersonii as one of the most promising genetic resources for potato breeding from the Southern Atlantic region.

青枯病菌引起的青枯病是马铃薯的主要细菌病害。Solanum commersonii Dun . (cmm; 2 n = 2 x = 24, 1 EBN) 是巴西南部、乌拉圭和阿根廷的本地物种，具有理想的性状，可用于与栽培马铃薯的渐进杂交育种，例如对青枯菌的抗性。在乌拉圭，已成功实现了 cmm 和马铃薯组 Tuberosum (tbr; 2 n = 4 x = 48, 4 EBN)之间的杂交，从而产生了 1、2 和 3 个回交后代。本研究的目的是表征一个回交 3 后代（BC ₃) 使用细胞遗传学、遗传学、形态学和农艺学描述符。对青枯菌的抗性表现出海侵分离和与植物结构的关联。52% 的个体的染色体数量接近栽培马铃薯，没有证据表明 cmm 染色体优先丢失。所有 BC ₃个体都显示雄性不育，可能是由于核 - 细胞质相互作用。尽管在形态特征上存在广泛的分离，但大多数个体类似于轮回的 tbr 亲本。可能需要更多的回交结合青枯病抗性筛选，以允许进一步重组和从 cmm 中去除不需要的性状。BC ₃个体的存在，其染色体数接近 2n = 48，将来自 tbr 的形态特征与良好的抗性水平相结合，表明发生了基因渗入事件。这表明S. commersonii是南大西洋地区最有前途的马铃薯育种遗传资源之一。