Diallel Cross in Potato Cultivars (Solanum tuberosum L.) and Evaluation of Their Progenies Under Deficit Water Stress

This study was performed to assess superior potato clones for agronomic traits and water deficit stress tolerance in laboratory and greenhouse settings over 3 years (2016–2018). Four cultivars, ‘Satina,’ ‘Caesar,’ Savalan,’ and ‘Agria’ were used as parents and crossed by mutual hybridization based on a diallel cross using the Griffing III method. Of 279 successful crosses, 7,980 true potato seeds from 12 breeding populations were obtained, from which 2,313 seeds germinated and 244 hybrids were selected. The selected hybrids were cultured in triplicate in a splitplot based on a randomized complete block design. The main factor consisted of three levels of irrigation (100%, 80%, and 60% of available water) and a subfactor of 12 populations (♀‘Agria’ × ‘Satina’♂, ♀‘Agria’ × ‘Caesar’♂, ♀‘Agria’ × ‘Savalan’♂, ♀‘Satina’ × ‘Agria’♂, ♀‘Satina’ × ‘Caesar’♂, ♀‘Satina’ × ‘Savalan’♂, ♀‘Caesar’ × ‘Satina’♂, ♀‘Caesar’ × ‘Agria’♂, ♀‘Caesar’ × ‘Savalan’♂, ♀‘Savalan’ × ‘Satina’♂, ♀‘Savalan’ × ‘Agria’♂, and ♀‘Savalan’ × ‘Caesar’♂). In all three environmental conditions, the highest tuber yield and tuber weight per plant were related to ♀‘Agria’ × ‘Caesar’♂. The most general combining ability that produced positive and significant tuber yield in mild and severe stress conditions was in ‘Agria’ and ‘Caesar’ cultivars. Therefore, these cultivars can easily transfer these traits to offspring and increase the expression of these traits. The specific combining ability between potato cultivars had positive and significant effects on tuber yield under the growth conditions tested. These crosses can be used for the production of drought resistant potato clones.