Natural hybridization between Gladiolus palustris and G. imbricatus inferred from morphological, molecular and reproductive evidence

作者：Szczepaniak Magdalena^*; Kaminski Ryszard^*; Kuta Elzbieta^*; Slomka Aneta^*; Heise Waldemar^*; Cieslak Elzbieta^*

来源：Preslia, 2016, 88(1): 137-161.

• AFLP
• generative reproduction
• Gladiolus x sulistrovicus
• interspecific hybridization
• morphometrics
• new nothospecies
• nrDNA
• plastid DNA
• pollen viability
• vegetative propagation

While studying the extremely rare species, Gladiolus palustris, in Poland, putative hybrid plants were discovered. Natural hybridization between G. palustris and G. imbricatus was confirmed by chloroplast (psbA-trnH and rpl32-trnL) DNA and nuclear ribosomal DNA (ITS1) sequences, AFLP markers and macro-, micromorphological and reproductive characters. Based on molecular data, the hybridization events are likely to have occurred relatively recently with G. palustris as the maternal species and G. imbricatus as the pollen donor in interspecific crosses. The existence of a shared common cpDNA haplotype in all hybrids and G. palustris indicates unidirectional hybridization. A new nothospecies, G. xsulistrovicus, is described. Analyses of AFLP data and polymorphisms of ITS1 sequences showed additive inheritance of parental genomic fragments in G. xsulistrovicus. The hybrids exhibited either morphological similarity to G. imbricatus or intermediateness in phenotypic characters. The corm structure of flowering plants and seed capsules clearly distinguish the hybrid. The new taxon is characterized by a lower generative reproduction than the parental species, however hybrids produce similar to 50% viable pollen and seeds, which allows them to produce subsequent hybrid generations. The weak generative reproduction was enhanced by highly efficient vegetative propagation. The western part of the Balkan Peninsula and adjacent areas (Croatia, Bosnia and Hercegovina, Serbia, northern Italy) and central Europe (Poland, the Czech Republic, Slovakia, eastern Austria, Hungary) are the most likely areas where G. xsulistrovicus will occur. Hybridity in the context of G. palustris conservation is discussed.

• 出版日期2016-3