A case study of potato germplasm enhancement using distant late blight resistant wild relatives

Abstract

Improving potato late blight (LB) resistance is essential for ensuring food security, particularly using wild relatives endemic to Phytophthora infestans‐prone regions. However, reproductive barriers can impede the transfer from potato wild relatives (PWR) to the cultivated genepool. This study sought to incorporate potentially novel LB resistance from wild diploid accessions of Series Piurana (Solanum chiquidenum, Solanum paucissectum, and Solanum piurae), Tuberosa (Solanum cajamarquense), and Megistracroloba (Solanum sogarandinum) into tetraploid potato. Trough rescue pollination, 699 diploid interspecific hybrids were obtained, of which 385 displayed LB resistance in two endemic environments. Based on a comprehensive evaluation, including assessing 2n pollen production, 14 diploid interspecific hybrids were selected to continue the introgression process. These pre‐bred stocks were then used in interploidy (4x‐2x) crosses to incorporate their LB resistance in the cultivated tetraploid background. Assessment of 1978 genotypes resulting from interploidy crosses under endemic disease pressure yielded 717 hybrids with moderate to high levels of LB resistance. Evaluation of pollen viability and ploidy revealed moderate fertility and predominantly tetraploid genotypes. Reassessment of LB resistance on this new subset of hybrids further identified 214 genotypes with sustained resistance. Among them, 12 tetraploid hybrids with low glycoalkaloid content, favorable agronomic, and post‐harvest attributes were identified as crossing‐friendly stocks. Notably, 11 of these hybrids were derived from S. cajamarquense and one from S. sogarandinum. These promising 4x hybrids are now primed to be incorporated into potato breeding programs.

Potato and sweetpotato breeding at the International Potato Center: approaches, outcomes and the way forward

“…Orange lines ending in circle show the end point of the pipelines while the orange lines ending with an arrowhead depict pipelines that continue. 1 Reynolds and Ewing ( 1989 ), Watanabe et al ( 1994 ), Watanabe et al ( 1995 ), Mendoza and Haynes ( 1974 , 1976 ), Mendoza, ( 1989 ), 2 Li et al ( 2012 ), Lindqvist-Kreuze et al ( 2014 ), Lindqvist-Kreuze et al ( 2021 ), Jiang et al ( 2018 ), 3 Mihovilovich et al ( 2007 ), Velásquez et al ( 2007 ), 4 Amoros et al ( 2020 ), 5 Pérez et al ( 2001 ), Trognitz et al ( 2001 ), Pérez et al ( 2022 ), Villamon et al ( 2005 ), Lindqvist-Kreuze et al ( 2010 ), Ordoñez et al ( 2023 ), 6 Benavides et al ( 2017 ), Muñoa et al ( 2022 ), 7 Ciampi and Sequeira, ( 1980 ), French and Lindo ( 1982 ), Priou et al ( 2005 ), Gutarra et al ( 2015 ), 8 Niederhauser and Villarreal ( 1986 ), 9 Pictipapa ( 1995 ), 10 Mendoza et al ( 1994 ), 11 https://www.scribd.com/document/72800341/Red-LatinPapa-Red-Iberoamericana-de-Innovacion-en-Mejoramiento-y-Diseminacion-de-la-Papa# , 12 Sharma et al ( 2020 ) …”

“…CIP has taken steps to contribute to this possible transition of potato breeding. Firstly, a new germplasm source for the induction of haploids from tetraploid potato that combines advantages of the well-known IVP stocks (Hermsen and Verdenius 1973;Hutten et al 1994) was recently released (Ordoñez et al 2021). Secondly, selected elite tetraploid clones were pollinated with three haploid inducers (HI) (IVP-35, IVP-101, and the above-mentioned PL-4 to initiate conversion of advanced tropically adapted populations to sets of diploid inbred parental lines.…”