后生木质部

There is no transition between root and epicotyl of dicotyledonous seedlings with epigeal germination, whereas only having a directly simple connection between the tissues with the same radially developmental direction.

真叶叶迹的木质部与下胚轴中靠近韧皮部的后生木质部或次生木质部连接。根与上胚轴之间不存在维管组织的过渡、转变，而只是在同样发育方向的组织中有一种直接的简单的连接

It consists of the protoxylem and metaxylem.

包括原生木质部和后生木质部。

Ochikarawere studied in morphology. The results indicates that the Oochikara has lateral root primordium and lateral root, and RM109 has no those. The number of pericycle cells in protoxylem of RM109 reduces to the 77% of that of Oochikara ; the number of vessel in metaxylem increases, and the number of vessel Ⅰ is the 149% of that of Oochikara ; the number of vessel Ⅱ is the 321% of that of Oochikara ; and the vessels arrange disorderly.

ochikara的冠根组织形态进行比较，结果表明，大力品种可观察到侧根原基及侧根，而RM1 0 9均无；RM1 0 9的原生木质部间中柱鞘细胞数目减少，为大力的 77%；后生木质部导管数增加，其导管I的数量为大力的 1 4 9%，其导管Ⅱ的数量为大力的 3 2 1 %，且导管排列散乱。

Scalariform thickening A type of secondary wall formation consisting of interlaced helical bands of thickening giving a ladderlike formation. It allows for very little further extension, and is found in tissues such as metaxylem tracheids and vessels, which do not elongate after maturation.

梯纹加厚：是植物细胞次生壁的一种形态结构，壁由加厚过程中相互交错成梯状形态的螺旋带形成，其可延伸性很小，多存在于后生木质部管胞和导管等一些成熟后便不再延伸的管状分子中。

The protoxylem vessels initiated lignification in the early stage of vascular bundle differentiation, whereas metaxylem vessels and fiber walls started lignification from the middle lamella and cell comers after completion of vascular bundle differentiation. The walls of most parenchyma cells lignified after the stem reached its full height, while a few parenchyma cells remained non-lignified even the culm is 7 years old.

研究结果表明：毛竹茎的原生木质部导管在维管束发育早期就已木质化；后生木质部导管和纤维细胞在维管束分化完成后，自胞间层和细胞角隅处开始木质化；基本薄壁组织细胞木质化的发生较晚，通常在茎的节间完成伸长生长后才开始，但也有少数薄壁组织细胞始终保持非木质化的薄壁状态。

The part of the primary xylem that differentiates after the protoxylem and is characterized by broader vessels and tracheids.

后生木质部初生木质部中不同于原生木质部的一部分，以更宽的导管和管胞为特征

It also contains additional supporting tissue in the form of fibers and sclereids and some living parenchyma.

原生木质部和后生木质部组成初生木质部，是由顶端分生组织的原形成层发育而来。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。