Comparative Studies On Anatomical Structure Of Four Species Of Potentilla

The paraffin section method was used to compare the root,stem and leaf anatomical structure of Potentilla supina L.,P.flagellaris Willd.ex Schlecht.,P.chinensis Ser.?P.anserina L.in Changchun area.The anatomical structure was different among the three species.The theoretical basis was provided for the development,utilization and protection of natural resources and taxonomy.The comparative study on the anatomical structure of the four plants was conducted by using the theories of plant physiology,plant anatomy and ecology,and the status of the four plants in habitat,introduction,domestication and systematic evolution was discussed.The results were as follows:(1)The leaf type of four species of Potentilla is allogeneic-type leaves,and all have epidermal hair.The leaf stomata type of four species of Potentilla is irregular-type.The palisade parenchyma of the four species of Potentilla are all 2-layer and long cylindrical,while the sponge parenchyma was relatively short and irregular,with obvious cell gaps.At the same time,there are also significant differences in leaf structure density,the thickness ratio of the palisade parenchyma to the sponge parenchyma,and vascular bundle structure among the four species of Potentilla.The CTR of P.supina,P.flagellaris,P.chinensis,P.anserina is 40.94%,38.00%,41.68%,39.79%.The thickness ratio of the palisade parenchyma to the sponge parenchyma of the four species of Potentilla is 1.32,1.17,2.09,1.30.The stomatal index of four species of Potentilla is 18.08%,17.85%,18.27%,18.01%.The stomatal density is 156.58 / mm2,126.35 / mm2,278.94 / mm2,137.45 / mm2.The leaf structure characteristics of the four species of Potentilla angustifolia reflect the close relationship of the same genus,and the differences between different species also reflect the adaptability to the environment.And the above characteristics indicate that the drought tolerance and cold tolerance of the four species of Potentilla are: P.chinensis >P.supina >P.anserina>P.flagellaris.(2)The anatomical structures of the stems of the four species of Potentilla are similar,all of which are composed of three parts: epidermis,cortex and middle column,and all of which have only one layer of epidermis.From the transverse section of the stem of the four species of Potentilla,it can be seen that they are all infinite external tough vascular bundles arranged in a ring.The number of vascular bundles of the four species of Potentilla:P.supina is18,P.flagellaris is 5,P.chinensis is 16,P.anserina is 9.The thickness of the pith of the four species of Potentilla is: 2162.91 ± 302.59?m,464.79 ± 64.11?m,3330.75 ± 310.39?m,1019.07 ±149.84?m.The type of vessel of the stem of the four species of Potentilla are all ring and threaded.The thickness ratio of the vascular tissue to the ground tissue(cortex and pith)is 15.36%,31.98%,12.82%,28.13%.The drought resistance of the four species of Potentilla is: P.chinensis >P.supina >P.anserina>P.flagellaris.(3)The epidermis of the anatomical structures of the roots of the four species of Potentilla is all composed of one layer of cells,and the number of cortex was large,with 8?18 layers of parenchyma cells,and the middle column is composed of primary xylem,primary phloem,middle column sheath and parenchyma.The growth and development of the roots of the four species of Potentilla is all in the outer beginning type.The primary xylem of the first root of P.chinensis and P.anserina are three prototypes,the primary xylem of the first root of P.flagellaris is four prototypes,and the first root xylem of the first root of P.supina is a multiple prototype.The vessel diameter of the root of the four species of Potentilla.The vascular tissues of the first root of four species of Potentilla is relatively developed.The vessel diameter of the primary xylem are 65.35±19.66?m,58.68±18.09?m,66.47±19.88?m,61.13±18.39?m.The results showed that the drought tolerance of four species of Potentilla was from strong to weak is: P.chinensis >P.supina >P.anserina>P.flagellaris.(4)The type of vessel of the stem of P.supina,P.flagellaris,,P.anserina are all annular vessel,spiral vessels,type of vessel of the stem of P.chinensis is annular vessel,spiral vessels and reticulate vessel.There are more evolved characteristics of reticulate vessel.At the same time,the original characteristics of P.chinensis is preserved.The diameter of the vessels of 4 species of Potentilla is the largest,and the diameter of the branches of Potentilla is the smallest,which also reflects the more evolved position of P.chinensis.