Type of presentation: Poster

LS-6-P-1540 The taxonomic and phylogenetic studies on and related genera

Yang T.1, Tian C. M.1, Liang Y. M.2, You C. J.1

1The Forestry Institute, Beijing Forestry University, Beijing, China, 2Museum of Beijing Forestry University, Beijing, China

Email of the presenting author: [email protected]

The Pucciniastrum was first established by Otth in 1861 with a type . But the taxonomic treatment of this genus with the genus Calyptospora and Thekopsora was different among researchers. The genus Thekopsora was described by Magnus in 1875 based on the species Thekopsora areolata. It was distinguished from Pucciniastrum only by the position of the telia, namely in Pucciniastrum teliospores develop underneath the epidermis of plants, but within the epidermal cells of plants in Thekopsora. Calyptospora was established by Kühn in 1869, consisting of a single species Calyptospora goeppertiana. This species was distinguished from Thekopsora by the absence of the uredinia and formation of teliospores on stems (Pady 1933, Faull 1938). Although these three genera could be distinguished by the position of telia, other morphological characteristics were similar. In earlier studies, some authors did not consider the position of telia as an important taxonomic characteristic and treated Thekopsora and Calyptospora as synonyms of Pucciniastrum, thus, Pucciniastrum as broad sense (Dietel 1900, Fischer 1904, Arthur 1907-1925). In order to get a clearer understanding of the relationship among Pucciniastrum, Thekopsora and Calyptospora, phylogenetic analyses of 28s rRNA is applied in this research along with the morphological studies. The characteristics of both uredinia and telia were observed under the light microscope and scanning electron microscope. Sequences of genera of Pucciniastreaece were used in this study. And it is also the first time to use the molecular studies on the systematic research of Pucciniastraceae. The phylogenetic results showed that species of these three genera did not assemble in separate clades on the basis of genus. Species of these three genera were crossed and separated in three main clades which had a better correspondence with the characteristics of the ostiolar cells of the uredinia ranther than the location of the telia. That is to say, species which had well-developed and smooth ostiolar cells (Group Ⅰ), had no well-developed ostiolar cells (Group Ⅱ)and had well-developed and coarsely ostiolar cells (Group Ⅲ) formed three distinct lineage (Fig.1; 2). It was the first time to use comparative analyses of molecular phylogeny and morphology to study of the taxonomic status of Pucciniastrum, Thekopsora and Calyptospora. It suggested that it is inappropriate to distinguish these three genera according to the position of telia, and we propose a combination of these three genera and treat them as broad Pucciniastrum. Also, the result implied that the characteristics of the uredinial ostiolar cells had a closer relationship with the evolution of these genera rather than the telia.

Acknowledgement: This research is supported by the NSFC in China (NO.31070572). Thank to the herbaria HH, TSH, HMAS, HMNWFC. We are grateful to Dr. M. Kakishima and Dr. Y. Ono for their help.

Fig. 1: A tree formed based on 28S sequences with maximum parsimony method. Bootstrap values were calculated from 1000 replications. Parsimony bootstraps greater than 40% are shown. Sequence of betulinum was used as out group. The bar of the picture stands for 20μm.

Fig. 2: A tree formed based on 28S sequences of species of Pucciniastraceae with maximum parsimony method. Bootstrap values were calculated from 1000 replications. Parsimony bootstraps greater than 40% are shown. Sequence of Puccinia hordei was used as out group.