初生木质部

原生木质部：初生木质部的成分，最早由原形成层形成。

Protoxylem The PRIMARY XYLEM elements that are formed from the procambium first .

根的初生木质部多为二原型，少数为三原型；成熟根的结构以次生结构为主。

The primary xylem is diarch , triarch is few . Mature structure mainly depends on the secondary structure .

蓝靛果忍冬初生木质部发育为外始式，根的初生结构为8原型。

Primary xy-lem is exarch , primary structure of root is 8 polyarch .

是初生木质部的内，外方都有初生韧皮部分布的一种维管束排列方式。

Bicollateral bundle The arrangement of tissues in the vascular bundles in which the phloem is situated on both sides of the xylem .

结果表明：不同直径大小的横走侧根均由周皮、次生维管组织和四原型的初生木质部构成。

The results showed that all the cross branch roots of different sizes consisted of periderm , secondary vascular tissue and tetrarch primary xylem .

星状中柱，初生木质部外始式，初生韧皮部呈孤岛状，呈径向辐射状排列位于初生木质部之间，中央形成微弱的髓。

It has Actinostele , primary xylem is exarch , primary phloem located between primary xylems like an island . The pith is shaped in the middle .

结果：根横切面上栓内层的石细胞环带和次生木质部导管的排列方式、初生木质部为四原型等为显微鉴别特征；

Results : The circular belt of sclereids in the phelloderm , secondary xylem vessel order of the transverse section , and tetrarch of the primary xylem were microscopic characters .

智囊团的经济特质是显而易见的。结果表明：内皮层都具有凯氏带，幼根均具有明显的髓，初生木质部均为外始式四原型；

The economic feature is obvious . shows that of all types casparian strip exits in endodermis and evident pith does in young root ; primary xylem is exarch and tetrarch ;

初生木质部与初生韧皮部之间可见到2&3层排列规则或不规则的薄壁组织细胞，但是没有维管形成层的发生。

Between primary xylem and primary phloem there are 2 & 3 layers of parenchymatous cells , regularly or irregularly arranged , but no cambial zone can be recogni - zed .

这种植物的根茎维管组织的过渡区域，看不到一般双子叶植物中所见到的初生木质部束扭曲、分开或倒转的现象。

The transition region where root and stem meet showed no evidence of twisting , splitting or inversion of the strands in the primary vascular tissues which are common in most of the dicots .

老根由外向内依次为：周皮、次生韧皮部、形成层、次生木质部、初生木质部。在根中五叶木通木质部导管口径比三叶木通的大很多。

While for older roots , there are periderm , secondary phloem , cambium , secondary xylem and primary xylem . In root , the duct caliber of xylem in Akebia quinata ( Thunb . ) Decne .

根系由不定根组成，根的初生结构木质部为2～4原型，次生结构中栓内层较厚。

Its root system is composed of adventitious roots . The primary xylem of root is 2 ~ 4 arches , and the secondary structure of root is characterized by a thicker phelloderm .

结果表明，红麻初生韧皮部和次生木质部的纤维长度及其分布分别优于次生韧皮部和初生木质部；

The results showed that the primary phloem and the secondary xylem had advantages obviously in the fiber length and the fiber length distribution .