Studies On Comparative Anatomy Of Pinus Armandi Franch. And Pinus Prokoraiensis Y.T.Zhao, J.M.Lu Et A.G.Gu

Anatomic structures of neddles of Pinus armandi Franch.and Pinus prokoraiensisY.T.Zhao,J.M.Lu et A.G.Gu were studied by the methods of paraffin and two-dimensionalmicrotechnique and their wood structures were studied by the methods of fiberize,freehandsection and optical microtechnique,with a view to analyze and discuss inerspecificrelationship between P. armandi and P.prokoraiensis and provide anatomic evidences for theevolutionary status of Pinus prokoraiensis.The thickness of needles' cutin of P. prokoraiensi(s2.65-3.65μm) was thincker than thatof P. armand(i2.25-3.25μm), which showed that P. prokoraiensis had a stronger cold resistantability.Their cells of hypoderm of neddles of P. prokoraiensis and P. armandi were both onelayer. The methophyll of P. armandi were cinquefoil-shaped and the cell walls had innerplications, but the cell walls of P. prokoraiensis methophyll had fewer inner plications andeven some had no inner plication, which showed that cell metabolism and photosynthesis of P.armandi neddles were stronger than those of P. prokoraiensis. Transfusion tissues of P.armandi and P. prokoraiensis were both developed and belonged to primitive pinus-type. Oncross-section,xylem of P. armandi neddle was semiorbicular but that of P. prokoraiensis wasridge-shaped. Their tracheid cells of veins both had helical thickening, which indicated thatboth of them were primitive.Growth rings of P. prokoraiensis and P. armandi were gradual chaging-type. Therewere more resin ducks and were not noly single-resin ducks but also multi-resin ducks in P.armandi. There were no elongitudinal parenchyma on their cross-section.Bordered pits of tracheids of P. armandi were more uniserial and pit aperture wasrounded.Pit aperture of P. prokoraiensis was rounded,elliptic and slit-shaped. Cross-field pits of P.armand and P. prokoraiensis were both window-like (one to four pits) . Pit aperture of cross-fieldpit of P. armand was rounded but that of P. prokoraiensis was tetragonal. Their wood rays wereboth composed of parenchyma cells and ray tracheids, which was primitive character.Wood rays of P. armand and P. prokoraiensis on tangential section both had two shapes,that was, uniserial wood ray and spindle wood ray. The height of uniserial wood ray of P.armand was one to eighteen cells and that of P. prokoraiensis was one to sixteen cells.The avarage length of P. armand tracheid was 2829.36μm, average diameter was 36.93μm,and the end tails were evident and slight. The avarage length of P. prokoraiensis tracheid was2534.11μm, average diameter was 37.89μm, and the end tails were variously shaped, such asfinger-shaped and wedge-shaped. From the angle of phylogeny, the evolutionary trend of tracheidlength was from long to short, so P. armand was primitive.And the end tails of P. armand wereevident and slight which was also the primitive character.