Study On Phylogenetic Relationships Of Potentilla In Inner Mongolia Based On Morphology And Various Genomic Sequences

The Potentilla L. is a large genus which belong to family Rosaceae,contain rich and various species, with high values for economy and ecology.The common species of Potentilla from Inner Mongolia were researched on epidermal micro-morphology characters and the leaf anatomical structure, in addition, the phylogenetic analyses was made by the nuclear ribosomal internal transcribed spacer(ITS) DNA sequence and chloroplast DNA trnL-F sequence, and then the key to Potentilla was perform ed. The main results as follows:1. The phylogenetic analysis for Potentilla by nrDNA ITS sequence indicated that one of the two main clades within P. fruticosa, P. glabra, P.parvifolia, P.bifurca, P.bifurca var. major from the sect. Rhopalostylae and P.anserina from the sect. Leptostylae, they were clustered at the base of the tree,the ser. Fruticosae in the Sect. Rhopalostylae was well supported. The plants of sect. Coaostylae and sect. Potentilla were clustered together forming second clade, The plants of sect. Coaostylae were clustered together with well support except P.acaulis from sect. Coaostylae being clustered into.2. Based on non-coding cpDNA regions trnL-F: The strict consensus tree of trnL-F divided all species of Potentilla also into two clades. The sect.Rhopalostylae were also clustered together, its ser. Fruticosae were supported well. P.anserina from sect. Leptostylae was clustered alone at the base of another clade near sect. Coaostylae and sect. Potentilla. In this clade, the plants of sect. Coaostylae were also clustered together and P.acaulis from the sect. Potentilla clustered into again. The result of trnL-F showed that the four sections were supported well except sect. Potentilla. The strict consensus tree of the combined sequences of ITS and trnL-F was similar with the ITS.3. Leaf epidermal micro-morphology characteristics: The types of trichome include pubescence, arachnoid hair, stellate hair, strigose hair,sericeous hair, glandular hair, tomentose etc on the upper epidermis and the pubescence was the most common; Trichome on lower epidermis were with dense hairs than its upper epidermis and the types of trichome include pubescence, stellate hair, strigose hair, sericeous hair, coactus hair, glandular hair, tomentose etc on the lower epidermis. Some species were with glandular hairs on their epidermis but were not mentioned such as P.reptans var.sericophylla, P.longifolia in “Flora intramongolica” and “Flora Reipublicae Popularis Sincae”. The shapes of upper and lower epidermis cells of leaves were polygonal and irregular, and most of them were polygonal. The patterns of epidermis cells were straight-curved, sinuolate and sinuate which were based on straight-curved. Stomata existed on the lower epidermis in most species, the lower epidermis stomatal length of their leaf was 15.76-28.06μm, stomatal density were 250-729 /㎜ 2, the stomatal index of plants were21.21-41.67, the difference of stomatal density had relations with the morphology of the species and growth environment.4. Leaf anatomical characteristics: The leaves of all kinds of species were bifacial, which had 1-3 layers palisade tissue that distributed on the upper epidermis, except P.bifurca which had 2 layers palisade tissues close to upper epidermis and 1 layer close to the lower epidermis. The upper and lower-epidermis were composed of monolayer cells. However, the cells in upper epidermis had a tight arrangement pattern and they were thicker than the lower ones. Their vascular numbers were 3-10.