Surviving in Mountain Climate Refugia: New Insights from the Genetic Diversity and Structure of the Relict Shrub Myrtus nivellei (Myrtaceae) in the Sahara Desert

摘要: The identification of past glacial refugia has become a key topic for conservation under environmental change, since they contribute importantly to shaping current patterns biodiversity. However, little attention been paid so far interglacial despite their role the survival relict species currently occurring in climate refugia. Here, we focus on genetic consequences range contraction populations evergreen shrub Myrtus nivellei, endemic Saharan mountains at least end last Green Sahara period, around 5.5 ka B.P. Multilocus genotypes (nuclear microsatellites and AFLP) were obtained from 215 individuals collected 23 wadis (temporary rivers) three main mountain ranges southern Algeria (the Hoggar, Tassili n’Ajjer n’Immidir ranges). Identical found several plants growing apart within same wadis, pattern taken as evidence clonality. Multivariate analyses Bayesian clustering revealed that diversity was mainly structured among ranges, while low isolation by distance observed each range. induced episode aridification likely increased M. without greatly affecting whole. here suggests high connectivity may have prevailed during humid periods, which is consistent with recent paleoenvironmental reconstructions.