Interactions between specific breeding system and ploidy play a critical role in increasing niche adaptability in a global food crop

Understanding the factors driving ecological and evolutionary interactions of economically important plant species is important for sustainability. Niches of crop wild relatives, including wild potatoes (Solanum section Petota), have received attention, however, such information has not been analyzed in combination with phylogenetic histories, genomic composition and reproductive systems. We used a combination of ordinary least-squares (OLS) and phylogenetic generalized least-squares (PGLM) analyses to identify the discrete climate classes that wild potato species inhabit in the context of breeding system and ploidy. Self-incompatible diploid or self-compatible polyploid species significantly increase the number of discrete climate niches inhabited. This result was sustained when correcting for phylogenetic non-independence in the linear model. Our results support the idea that specific breeding system and ploidy combinations increase niche divergence through the decoupling of geographical range and niche diversity, and therefore, these species may be of particular interest for crop adaptation to a changing climate.