A PPR gene cluster from Solanum aethiopicum underlies fertility restoration in cytoplasmic male-sterile eggplant (S. melongena L.)

Xiaohui Zhou, Songyu Liu, Hesbon Ochieng Obel, Yan Yang, Jun Liu, Lei Xia, Yuhui Wang & Yong Zhuang

TAG; February 28 2026; vol. 139; article 82

Cytoplasmic male sterility (CMS) and nucleus-controlled fertility restoration systems are essential tools for hybrid breeding to improve crop productivity. In eggplant (Solanum melongena), CMS lines have been widely developed through interspecific hybridization, but the genetics basis of fertility restoration remains poorly understood. In the present study, a fertility restorer (Rf) introgression line ‘3–26’ was generated through interspecific hybridization between S. aethiopicum and cultivated eggplant. The major Rf locus was fine-mapped to ~ 118.4-kb interval on chromosome 6 using whole-genome resequencing according to ‘67/3’ v3.0. Collinearity analysis revealed that this interval is an introgression fragment corresponding to a ~ 436-kb region in S. aethiopicum genome, which contained a cluster of 17 tandemly arranged pentatricopeptide repeat (PPR) genes. Among them, Solaet3_06g003840 is proposed as the best candidate according to RNA-seq, gene structure, and phylogenetic analysis. Further comparative syntenic analysis revealed that the Rf-PPR cluster is present in four other wild eggplant species, but absent in cultivated varieties. We further developed a Rf-linked KASP maker that is practically used for eggplant CMS/Rf breeding systems. These findings broaden our understanding of the fertility restoration for alloplasmic CMS systems and provide practical tools for MAS hybrid breeding in eggplant.

See https://link.springer.com/article/10.1007/s00122-026-05190-0