Two new species of Pustula (Albuginales, Oomycota) from Junggar Basin in China based on morphology and molecular data

Two new species of Pustula, P. cancriniae and P. xinyuanensis associated with Cancrinia discoidea and Convolvulus gortschakovii, respectively, are described based on morphological and molecular characters. They were placed in Pustula based on the following morphological characters: primary sporangia with an overall thickened wall, secondary sporangia with laterally thickened annulus, and oospores with reticulate wall ornamentation. In phylogenetic analysis inferred from the cox2 mtDNA region, P. xinyuanensis and P. cancriniae formed two independent lineages, apart from other known species of Pustula. Both morphological and molecular evidence confirmed the placement of the two species in Pustula and showed its relations with similar species in the genus. Moreover, this is the first record of Pustula on Convolvulaceae in the world.