Abstract
Summary●In tomato clade, bothself-incompatibility(S-) locus-dependent and –independent mechanisms are present in unilateral incompatibility (UI). Several stylar UI factors mediatingS-locus-independent mechanism have been gradually uncovered, however, related pollen UI (pui) factors still await more studies.●Quantitative trait loci (QTL) mapping, comparative transcriptomics and introgression lines (ILs) /inbred backcross lines (BILs)-based functional analysis were applied for identification and functional validation ofpuiQTLs between self-compatible (SC)Solanum lycopersicumand SCS. pennelliiLA0716.●In addition to the reportedpui10.1(SpFPS2), twopuiQTLs (pui6.2andpui12.1) were identified. Pollen tubes of cultivated tomatoes introgressed with threepuiloci could partially break the stylar UI response in LA0716 styles. Furthermore, a conserved function ofpui12.1was found in the styles of SCS.habrochaitesLA0407 and SCS.chmielewskiiLA1028. Three candidate genes linked topui6.2andpui12.1were screened for further analysis.●This study reveals a potential synergistic relationship of the threepuiQTLs in breaking stylar UI response of LA0716 and will advance our understanding of the genetic mechanisms underlying UI in the tomato clade.HighlightOur data revealed that breaking the stylar unilateral incompatibility ofSolanum pennelliiLA0716 requires not only the reported pollen UI (pui) factor but also another twopuiQTLs identified in this study.
Publisher
Cold Spring Harbor Laboratory