Studies On Anatomical Structure And Physiological Characteristics Of Cerasus Humilis (Bge.) Sok.'s Different Order Roots

In order to explore the anatomical structure and physiological characteristics of Cerasus humilis?Bge.?Sok.'s different order roots,five years' seedling Cerasus humilis?Bge.?Sok.was used in this trial.The root's order was graded by the root sequence method.Free-hand section was used in observing and measuring roots' cross-section structure.Vessels were isolated in chromic acid and nitric acid,observe and measure their structures.Vessels' models was made with resin complex legal system,took their pictures with a scanning electron microscope.roots' activity,protein content,free amino acid content,SOD activity,and the activity of nitric acid reductive enzyme of different order roots,etc were determined by the method of TTC,the method of Lorry,the indene triketone colorimetric,etc.The results indicate that:1.Cerasus humilis?Bge.?Sok.'s first and second order roots is primary root,with parenchyma,and their rates are as high as 88.44% and 80.61%,respectively;The third to sixth order roots are secondary roots,with periderm,and their thickness are 48.988 ?m?94.073 ?m?143.057 ?m?186.833 ?m,respectively.The resistance to external coercion increases with the rise of the rank.2.Vessels' diameter of Cerasus humilis?Bge.?Sok.'s first and second order roots are 17.815 ?m and 15.260 ?m and less than third to sixth order roots'.The density of first and second order roots' vessels are 1172.330·mm-2 and 836.000·mm-2,the ratios of the vessels that with out talil are 55.25% and 46.47%,the ratios of the pitted vessel are 88.46% and 90.38%,and all of them are larger than third to sixth order roots'.3.The mass of Cerasus humilis?Bge.?Sok.'s first and second order roots to the root system are only 4.18%.But the metabolism of them was active,the activity of them are up to 186.252 ?g·g^-1·h^-1,the numerical of active absorption area / total absorption area is 83.62%,and all of them are larger than third to sixth order roots'.4.Protein content of Cerasus humilis?Bge.?Sok.'s third order root is 18.33 mg·g^-1 and larger than other order roots.The third and fourth order roots Nmetabolically active.The content of protein was positively related to activities of GS and GDH.5.The activity of SOD in Cerasus humilis?Bge.?Sok.'s first and second order roots is up to 222.220 U·g^-1·min^-1,the activity of POD is up to 5.791 U·g^-1·min^-1 and the activity of CAT is up to 13.334 U·g^-1·min^-1,all of them are lager than third to sixth order roots'.But the activity of Souble sugars,starch,cellulose,free amino acid and proline in Cerasus humilis?Bge.?Sok.'s third to sixth order roots are lager than first and second order roots',they have significant or significant positive correlation.