金桂银桂丹桂四季桂脉序比较研究

采用脉络法对桂花的4个栽培品种,即金桂、银桂、丹桂和四季桂的叶片脉序进行比较研究.结果表明：桂花的4个品种均为环结曲行羽状脉;一级脉走向直行无分支,二级脉走向急转曲行,三级脉类型为结网型,呈直角网状;二级脉脉环被三级脉或四级脉的脉环包围,二级间脉均为复合;叶缘末级脉序结环;齿无腺点,齿尖简单,齿内主脉为三级四级脉,走向居中,直入齿内,无副脉;四季桂与其余3个品种之间区别较大,四季桂叶尖形状为戟尖,而其余3种的叶尖形状均为剑尖;四季桂一级脉与二级脉的夹角上部较下部为锐,其余3种夹角的变异接近一致.四季桂与金桂、银桂、丹桂亲缘关系较远,金桂、银桂、丹桂之间的亲缘关系更为接近.

A Comparative Study of Venation in Thunbergii,Latifolius,Aurantiacus and Semperflorens

A comparative study is made of the four cultivars of Osmanthus blossoms,namely the Thunbergii,Latifolius,Aurantiacus and Semperflorens to find out about their leaf venation.The findings showed that all of the four are brochidodromous camptodromous pinnate with a straight and unbranched primary vein;secondary vein is sharp and camptodromous,tertiary vein is reticulate,orthogonal.The loop of secondary vein is rounded by the loops of tertiary vein or quaternary vein.The intersecondary veins are all compound;the marginal ultimate venation takes the shape of a knotted ring;the teeth have no glands and the teeth tips are simple and within the teeth the primary vein has a tertiary or quaternary rein which point toward the middle and go right into the teeth without any accessory reins;the semperflorens is rather different from the other three varieties：the former has a killer tip while the other three have a sword-t ip-shaped leaf tip;the upper angle of Osmanthus fragrans var.semperflorens is sharper than the lower part,the angle variation of the other three kinds is approximately the same,indicating that the former has a rather distant genetic relationship with the latter three,and the latter three are genetically closer compared with the former.