Data from: Influence of niche similarity on hybridisation between Myriophyllum sibiricum and M. spicatum|植物杂交数据集|生态位分析数据集

The impact of ecological factors on natural hybridisation is of widespread interest. Here, we asked whether climate niche influences hybridisation 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 hybridisation between these two species in two co-occurring regions: northeast 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 hybridisation 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 hybridisation pattern and climate niche similarity suggests that the level of hybridisation 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 hybridisation patterns in plants.