Evolutionary relationships of Pemphigus and allied genera （Hemiptera： Aphididae： Eriosomatinae） and their primary endosymbiont, Buchnera aphidicola

Aphids harbor primary endosymbionts, Buchnera aphidicola, in specialized cells within their body cavities. Aphids and Buchnera have strict mutualistic relationships in nutrition exchange. This ancient association has received much attention from researchers who are interested in endosymbiotic evolution. Previous studies have foundparallel phylogenetic relationships between non-galling aphids and Buchnera at lower taxonomic levels （genus, species）. To understand whether relatively isolated habitats such as galls have effect on the parallel relationships between aphids and Buchnera, the present paper investigated the phylogenetic relationships of gall aphids from Pemphigus and allied genera, which induce pseudo-galls or galls on Populus spp. （poplar） and Buchnera. The molecular phylogenies inferred from three aphid genes （COI, COII and EF-la） andtwo Buchnera genes （gnd, 16S rRNA gene） indicated significant congruence between aphids and Buchnera at generic as well as interspecific levels. Interestingly, both aphid andBuchnera phylogenies supported three main clades corresponding to the galling locations of aphids, namely leaf, the joint of leaf blade and petiole, and branch of the host plant.The results suggest phylogenetic conservatism of gall characters, which indicates gall characters are more strongly affected by aphid phylogeny, rather than host plants.

Taxonomy and the evolutionary history of Micropeltidaceae

Micropeltidaceae species are flyspeck fungi which have been subjected to few systematic studies.We re-examined 27 genera which were accepted in the Micropeltidaceae and re-described them based on herbaria materials and protologues.Based on morphology and phylogenetic investigations,we transfer Micropeltidaceae to a new order,Micropeltidales(Lecanoromycetes).Genera with bluish or greenish upper walls(Dictyopeltella,Dictyothyriella,Dictyothyrina,Dictyothyrium,Haplopeltheca,Micropeltis,Scolecopeltidium and Stomiopeltopsis)are accepted in the new taxonomic concept for Micropeltidaceae.A molecular clock approach estimated the divergence time of the Micropeltidaceae crown group at 130(165–104)Mya,which also supports its rank as an order(diverging from 220–100 Mya).The evolutionary histories between Micropeltidaceae species and host plants are interpreted by cophylogenetic analyses calibrated by their divergence times.The result indicates that the diversification of Angiospermae(130–80 Mya)fosters the formation of genera of Micropeltidaceae mainly via cospeciation events,and this codivergent period would be an important reference when establishing generic boundaries of epifoliar fungi.