摘要
绵刺Potaninia mongolica的叶是一种顶端小叶具三裂片的羽状三出复叶,包括托叶鞘、叶柄及叶片。两侧生小叶原基发生发育较早,产生两侧生小叶。顶端小叶原基的不均匀生长较迟,产生三个裂片。两侧生裂片与两侧生小叶径向排列,位于近轴端。小叶原基中维管组织分化较迟。托叶鞘发育早期,两侧迅速延伸,包围苗端。叶柄发育较迟由居间分生组织的活动产生。绵剌叶小,密被长柔毛,角质层厚,气孔小密度大且下陷,栅栏组织发达,叶柄、托叶鞘中分布大量的厚壁组织。这些特征都有利于植株在缺水状况下保持挺立状态,增加光合作用及水分输导能力。另外侧脉维管束鞘类似C4植物的花环结构,是否与C4光合途径有关,有待进一步证实。
The leaf of Potaninia mongolica is a kinci of leafit in top and a ternate leafpingate compound leaf which has three shatters, including ocrea, leaf stalk and leaf blade. Genesis and de-velopment of the rudiment of two adnation-leafits are earlier, which forms two adnate leafits. Uneven growth of rudiment of leafit in top is later. It forms three shatters. Two adnate shatters and two adnate leafits are radial range,and they locate in the end near axle. Differentiation of facicular organism in rudiment of leafit is earlier, but in shatter it is late. When the ocrea devel-ops in the early stage, it extends rapidly in both sides and surounds shoor apex. The deve lopment of stipe starts later. It forms from germination between two parties of meristem. The leaf of potaninia mongolia is small, which is covered by a layer of long pliable pubescence. Its cuti-cle is thick, and the stoma is small,dense and cryptopore. The barricado tissue is developed, and a great quantity of sclerenchyma distributes in the leaf stem and the ocrea. These characteristics help the plant keep standing upright even 'if when there is shortage of water, and increase the a-bility of photosynthesis and conducti on of water. in additon, whether the bundle end in lateral vein like garland-structure of C4 plant,is related to the way for C4 photosynthesis needs to be further confirmed.
出处
《农业科学研究》
1992年第2期5-12,共8页
Journal of Agricultural Sciences
关键词
叶
解剖构造
leaf, anatomical structure
