Exploring pollinator dependence in tomato crops across a domestication gradient

Tomato (Solanum sp.) is one of the world’s most widely cultivated and economically significant horticultural crops. The commercialization of tomato production has caused an increase in the breeding of hybrid varieties in the pursuit of reliable yields. While pollination can improve the yield of some tomato varieties, the extent of pollinator dependence appears to vary across varieties and is not well characterized. Tomato flowers require a specialized pollination technique referred to as ‘buzz pollination’ in which certain pollinators, such as bumble bees (Bombus spp.), vibrate at specific frequencies to release pollen from tiny slits in the anther. This experiment was designed to compare pollinator dependence among a diverse panel of tomato germplasm. We will test how the length of pistil protrusion from the anthers, a factor that can predict pollen transfer efficiency and fruit yield, will dictate how reliant the tomato flowers are on buzz pollination versus pollination by wind or hand pollination. To explore this, we will compare hybrid, heirloom, and wild tomato genotypes which differ in floral morphology and selection histories. We anticipate results that show hybrid tomatoes to be the least pollinator dependent and wild tomatoes to be the most.