Data from: Influence of niche similarity on hybridisation between Myriophyllum sibiricum and M. spicatum

The impact of ecological factors on natural hybridization is of widespread
interest. Here, we asked whether climate niche influences hybridization
between the two closely related plant species Myriophyllum sibiricum and
M. spicatum. Eight microsatellite loci and two chloroplast fragments were
used to investigate the occurrence of hybridization between these two
species in two co-occurring regions: north-east China (NEC) and the
Qinghai-Tibetan Plateau (QTP). The climate niches of the species were
quantified by principal component analysis with bioclimatic data, and
niche comparisons were performed between the two species in each region.
Reciprocal hybridization was observed, and M. sibiricum was favoured as
the maternal species. Furthermore, hybrids were rare in NEC but common in
the QTP. Accordingly, in NEC, the two species were climatically distinct,
and hybrids only occurred in the narrow geographical or ecological
transition zone, whereas in the QTP, obvious niche overlaps were found for
the two species, and hybrids occurred in multiple contact zones. This
association between hybridization pattern and climate niche similarity
suggests that the level of hybridization was promoted by niche overlap.
Compared with the parental species, similar climate niches were found for
the hybrid populations in the QTP, indicating that other environmental
factors rather than climate were important for hybrid persistence. Our
findings highlight the significance of climate niche with respect to
hybridization patterns in plants.