Late-acting self-incompatible system, preferential allogamy and delayed selfing in the heteromorphic invasive populations of Ludwigia grandiflora subsp. hexapetala

• DOI: 10.24072/pcjournal.108
• Publication Date: 2022-04-06T16:16:44Z
• Authors: Luis O. Portillo ...; Maryline Harang; Michel Bozec; Jacques Haury; Solenn Stoeckel; Dominique Barloy
• Keywords: Selfing; Floral biology

Breeding system influences local population genetic structure, effective size, offspring fitness and functional variation. Determining the respective importance of self- cross-fertilization in hermaphroditic flowering plants is thus important to understand their ecology evolution. The worldwide invasive species, Ludwigia grandiflora subsp. hexapetala (Lgh) presents two floral morphs: one self-compatible short-styled morph (S-morph) self-incompatible long-styled (L-morph). In this study, we identified breeding systems western European experimental natural populations Lgh by comparing structural characteristics pollen style, studying cross-pollen tube elongations viability resulting seeds seedlings both morphs. Our results showed no differences shape stigma surfaces matter morph. L-morph flowers, self-pollen tubes were stopped tardily, ovarian area, unable fertilize ovules. This first formal identification a late-acting, prezygotic (LSI) genus contributes case LSI an additional family within Myrtales order. S-morph always succeeded self-fertilize ovules that nearly all developed into viable seedlings. However, elongated faster than individuals may advantage preferential allogamy over selfing when available despite its self-compatibility. As expected late-acting systems, flowers authorised 0.2‰ selfed during uppermost season, increased 1‰ at end season. Such delayed resulted significant quantity floating seeds. They contribute regeneration, seed bank propagation L-morph, which explain invasion success worldwide. Management plans would gain consider identified.