Comparison In Morphology Anatomy And Karyotype Between Pinus Tabulaeformisf.Shekanensis And P. Abulaeformis

Pinus tabulaeformis f. Shekanensis is only distributed in Ziwuling Loess Plateau. ThePinus tabulaeformis f. Shekanensis has many advantages comparing with Pinustabulaeformis such as taller body, straighter trunk and more natural pruning. The populationof Pinus tabulaeformis f. Shekanensis in this region constitutes important component of theecosystem. The classification status of Pinus tabulaeformis f. Shekanensis was unconfirmed,Zhu Zhicheng and Le Tianyu considered it was a variation of P. tabulaeformis species inLoess Plateau, but it was not recorded in authoritative writings such as Flora RepublicasePopularis Sinicae and Dendrologia Schensiensis. In this research, morphology anatomy,karyotype and physiology were compared between two kinds of pine in order to provide basisof classification for Pinus tabulaeformis f. Shekanensis. The results were showed as follows:(1)In adult trees, the thickness and width of needle of Pinus tabulaeformis f.Shekanensis were much shorter than P. tabulaeformis. The average of resin canal area andquantity of needle of Pinus tabulaeformis f. Shekanensis were1394.40μm2and4.87respectively, for P. tabulaeformis, the average of which were respectively1651.81μm2and6.70. The width of early wood and late wood of Pinus tabulaeformis f. Shekanensis werewider than that of P. tabulaeformis. The average of the width of early wood to late wood ratioof Pinus tabulaeformis f. Shekanensis was1.97, for P. tabulaeformis, the average of whichwas1.94. The average of tracheids’ walls to lumen ratio of early wood of Pinus tabulaeformisf. Shekanensis and P. tabulaeformis were0.188and0.193respectively, and the average oftracheids’ walls to lumen ratio of the late wood of Pinus tabulaeformis f. Shekanensis and P.tabulaeformis were respectively0.550and0.617. The average area of lengthways resin canaland amphitropous resin canal of Pinus tabulaeformis f. Shekanensis s were3620.69μm2and2727.62μm2respectively， for P. tabulaeformis, the average of which were respectively5113.65μm2and3571.54μm2. The tracheid length of Pinus tabulaeformis f. Shekanensis waslittle shorter than that of P. tabulaeformis.(2)The karyotype formula of Pinus tabulaeformis f. Shekanensis was12n=20m(2SAT)+4sm(4SAT), the tenth and eleventh pairs of chromosome were submetacentricchromosome and others were metacentric chromosome. The karyotype formula of P. tabulaeformis was12n=20m(4SAT)+4sm(2SAT), the eleventh and twelfth pairs ofchromosome were submetacentric chromosome and others were metacentric chromosome.The satellites of two kinds of pine were both located at ninth, tenth and eleventh pairs ofchromosome, and the karyotypes were all1A type. Furthermore, the asymmetry indexes were55.57%and57.06%respectively.(3) The seeds of Pinus tabulaeformis f. Shekanensis and P. tabulaeformis werecultivated at the same place in order to comparing the differences of anatomical structure andphysiological feature between two kinds of pine in seedling stage. The results showed: Thecontent of chlorophyll A, chlorophyll B, total chlorophyll and soluble protein in needle ofPinus tabulaeformis f. Shekanensis were little lower than P. tabulaeformis, but waterpotential in stem, peroxidase activities in needle and superoxide dismutase activities in needleof Pinus tabulaeformis f. Shekanensis were higher than P. tabulaeformis. The thickness andwidth of needle of Pinus tabulaeformis f. Shekanensis were much shorter than that of P.tabulaeformis. The average area of lengthways resin canal of Pinus tabulaeformis f.Shekanensis was555.49μm2, for P. tabulaeformis it was892.87μm2. The cross-sectionalarea of pith of Pinus tabulaeformis f. Shekanensis was smaller than P. tabulaeformis. Thewidth of xylem, phloem, cortex and periderm of Pinus tabulaeformis f. Shekanensis were0.234mm,0.082mm,0.125mm and0.056mm respectively, for P. tabulaeformis it were0.389mm,0.113mm,0.207mm,0.084mm. The average area of lengthways resin canal ofPinus tabulaeformis f. Shekanensis was1822.68μm2, for P. tabulaeformis it was3575.38μm2.