Plastome reconstruction to understand the hybrid origin of the invasive Kalanchoe ×houghtonii D.B. Ward (Crassulaceae)

Póster presentado en el III Simposio Anual de Botánica Española celebrado en el Institut Botànic de Barcelona, Barcelona, 25-26 de noviembre de 2022Invasive alien species (IAS) are one of the main causes of extinction of native species, and their spread is currently favoured by climate change and globalisation. Directly related to globalisation, one of the key biological factors leading to invasiveness in plants is hybridisation. This process can decrease the deleterious effects of a population bottleneck and/or confer an increased adaptative capacity. We are approaching the study of invasiveness through the study of the hybrids Kalanchoe ×houghtonii whose parental species are Kalanchoe daigremontiana and Kalanchoe tubiflora, both from Madagascar. These taxa are causing increasing damage to the native flora of the coastal areas of the Mediterranean region by the displacement of native species. Although the first known hybrids were artificially created by year 1939 in California, it is also possible that hybridisation has occurred naturally. According to our cytogenetic results, there are two cytotypes naturally occurring in the Mediterranean area, a triploid (2n = 3x = 51) and a tetraploid (2n = 4x = 68), the latter reporting an invasive behaviour. To better understand the hybridization history and the invasive behaviour of Kalanchoe ×houghtonii, we aim to study the plastome sequences of the hybrids and parental species, from different locations in the Mediterranean region. Specifically, we aim to answer the following questions: (1) which species is the maternal plastome donor of the hybrids? (2) what is the genomic diversity among hybrid plastome sequences? and (3) could we infer single or multiple origins of the invasive hybrid