Abstract:
Chinese subtribe Conyzinae (Asteraceae:Astereae) consists of three small genera,
Conyza,
Microglossa and
Thespis. To date,however,the molecular phylogenetic relationships among African
Conyza,and Chinese
Conyza,
Thespis and
Microglossa have not been investigated. The internal and external transcribed spacers of nuclear ribosomal DNA were used to reconstruct the phylogeny of Chinese Conyzinae through maximum parsimony and Bayesian analyses. Results showed that four Chinese
Conyza species and
Thespis divaricata belonged to a clade with most sampled African
Conyza,whereas two
Conyza stricta varieties and
Microglossa pyrifolia were embedded deeply within the subtribe Grangeinae clade.
Microglossa pyrifolia was closely related to
Psiadia pascalii. Based on phylogeny,we considered that (1)
C. stricta and
C. incisa should be treated as a separate genus that belongs to subtribe Grangeiane;(2) four Chinese
Conyza,
Thespis and most sampled African
Conyza belong to the genus
Eschenbachia.
Eschenbachia should belong to a new separate subtribe,while
Thespis should be treated as a section of
Eschenbachia.
Eschenbachia may have arrived at southern China by several long-distance dispersals from Africa;(3) it is reasonable to maintain the generic status of
Welwitschiella and
Microglossa and treat
Psiadia pascalii,
C. scabrida and
C. pyrrhopappa as members of
Microglossa.