Haustorial ultrastructure and morphology of Melampsorella and Thekopsora areolata.

摘要

The morphology and ultrastructure of dikaryotic haustoria (D-haustoria) of M. caryophyllacearum and M. symphyti differed. The haustorium of M. caryophyllacearum was branched apically and the haustorial neck was sheathed by a fold of the extrahaustorial membrane. A system of filamentous structures was present in the matrix fold around the neck. In M. symphyti, no such matrix fold was present, and the haustorial body was unbranched. D-haustoria of T. areolata were bulbous and unbranched. They differed from D-haustoria of other Thekopsora species by the presence of a matrix fold at the haustorial neck. To date, Melampsorella, Thekopsora and Pucciniastrum are the only pucciniastraceous genera, that have different haustorial types. The systematic implications are discussed.