Abstract Species of Solanaceae grow in rainforests, grasslands and deserts and especially montane/subalpine habitats of South America. The highest number of genera and species occurs in South America, but centres of species richness also are found in Africa, Australia, China and Mesoamerica. Information on embryo morphology was found for all eight subfamilies of Solanaceae and 236 species in 87 genera. Cestroideae, Pentunioideae, Nicotianoideae and Solanoideae have spatulate and linear-full embryos, while Duckeodendroideae, Goetzeoideae, Schizanthoideae and Schwenckioideae have linear-full embryos. Information on seed dormancy/germination was found for 167 species in 32 genera: 10 tree and 1 vine species in the tropics; 53 and 31 shrubs species in tropical and temperate zones, respectively; and 47 and 25 herb species in tropical and temperate zones, respectively. Physiological dormancy (PD) occurs in 94.5% of the 167 species; the other nine species had nondormant seeds. Regardless of subfamily, embryo morphology and vegetation region, most species have seeds with PD that can be broken during dry storage or cold stratification. Of the six types of nondeep PD, Type 2 occurs in a few temperate species; other types have not been documented. Soil seed banks have been documented in four subfamilies, 12 genera and 39 species, many of which are agricultural weeds. We identified questions that need to be answered about cold and heat tolerance of Solanaceae species, world distribution, especially in northern latitudes with a cold winter, and development of Type 2 nondeep PD as an adaptation of Solanaceae species that enhances survival in cold climates.
Baskin et al. (Fri,) studied this question.