The winner takes it all: a single genotype of Kalanchoe ×houghtonii is a global invader

Abstract

Invasive alien plant species pose a global challenge, and their impact is amplified by globalisation and the accelerating pace of climate change. In mild-climate regions, drought-tolerant invasive plants showing broad environmental tolerance have a competitive advantage. One example is Kalanchoe ×houghtonii (Crassulaceae), popularly known as “mother of millions”. It is a hybrid resulting from the interploid cross between K. daigremontiana and K. delagoensis, both native to Madagascar. Kalanchoe ×houghtonii, propagated as an ornamental plant, has emerged as a global invader in less than a century. Four morphotypes of this hybrid have been identified, with different ploidy levels and varying invasive capacities. Here we aim to investigate the genomic variability behind the invasion success of Kalanchoe ×houghtonii.