Phylogenetic Utility Of Chinese Rubus L. (Rosaceae) Based On NdhF Sequence

The genus Rubus L. belongs to Rosaceae and Rosoideae subfamily, which is also named Brambles. China, exceptionally rich in Rubus species, has 201 species and 98 varieties, as well as 138 specific species. Brambles are those Rubus species with edible fruits in horticultural productions. Due to the unsolved phylogenetic relationships within the genus including Brambles, it is difficult to identify and evaluate Rubus germplasms. At present, cytology method is too limited, and molecular systematics is the most promising method in the field. So we use ndhF sequence to assess the applicability of the sequence as well as the phylogeny and taxonomy level of the species in Rubus. Special attention will be paid to the wild species:Sect. Idaeobatus and Sect. Malachobatus. It can help to clarify the phylogenetic relationships, as well as the identification and classification of the excellent bramble germplasms. The results were listed as follows.1 The value of ndhF region of cpDNA in Rubus. Based on the sequenced results of all the samples, the aligned sequence was 1182 bp in the length, with 34.3% of G and C content, and 65.7% of A and T. Using the Rosa xanthina and Fragaria vesca as outgroups, the ndhF sequence revealed 88 variable sites (7.44%) and 47 parsimony informative sites (3.97%), respectively. The sequence divergence in sect. Idaeobatus was 4.8%, while it was only 1.2% in sect. Malachobatus. The phylogenetic tree had a high value of CI and RI, which afforded strong evidence of the phylogenetic relationships of Chinese Rubus. The clade had a high bootstrap support and posterior probability as well.2 The phylogenetic relationships of Chinese Rubus L.. Based on the ndhF sequence data, the Chinese Rubus formed a monophyletic group. The samples were divided into several well-supported clades according the classification of sections Idaeobatus, Malachobatus and Dalibardastrum. Futhermore, those samples from sections Malachobatus and Dalibardastrum formed a clade, while species of Sect. Idaeobatus were divided into several clades, revealing polyphyletic evolution. Within the sect. Idaeobatus, the samples from different subsections formed several clusters which mixed each other, probably indicating complicated phylogenetic relationships within the section. R. ellipticus and R. ellipticus var. obcordatus formed a clade together with 58% bootstrap support and 96% posterior probability. R. parvifolius from different localities was not formed together.