木质部的

What is the "annual ring" It is made of the xylem, the congregation of the pipes that carry water in a tree.

何谓『年轮』？输送水分的导管集合起来成为木质部，年轮就是由木质部构成的。

The primary cambium is found in the stem and root between the phloem and xylem cells, and by division gives rise to the secondary phloem and xylem in woody dicotyledonous plants.

它纵贯于根，茎等器官的木质部和韧皮部之间，是具有分生能力的组织。通过形成层的分裂可以在木本的双子叶植物中形成次生木质部和次生韧皮部。

In the primary structure of root, the primary xylem is diarch and the development of both the primary xylem and the primary phloem is exarch.

在根的初生结构中，其初生木质部为二原型，木质部及韧皮部的发育均为外始式。

The degree of lignification varies from slight in protoxylem to heavy in sclerenchyma and some xylem vessels, but values of 25-30% lignin and 50% cellulose are average.

不同部位的木质化的程度不同，原生木质部中只有轻微的加厚，而在厚壁组织和一些木质部导管中则进一步加厚，平均含25％-30％的木质素和50％的纤维素。

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 results showed that POD activity increased at first and then decreased in the skin and flesh of root. The peak occurred at 40 d and 60 d in the skin and flesh, respectively. POD activity in the skin was higher than that in the flesh at 30 d and then contrary results were observed. The higher POD activity was, the more POD isoenzyme was. The pattern of POD isoenzymes was different between skin and flesh at different vegetative growth stages. POD isoenzymes in the skin were composed of five monomers and four dimers while five dimers or two monomers, two dimers and one tetramer in the flesh. POD isoenzymes in the root were mainly acidic. POD localized mainly in the cell walls of periderm, cambium, xylem ray, xylem vessels and primary xylem.

结果显示，心里美萝卜营养生长期肉质根的皮和肉中POD活性均先升高后降低，分别在播种后第40 d和60 d出现峰值，30 d时皮中POD活性高于肉，之后则相反，酶活性最高时同工酶数目也最多，不同时期，皮和肉中同工酶种类不同；皮中POD同工酶由5个单体和4个二聚体组成，而肉中由5个二聚体或2个单体、2个二聚体和1个四聚体组成，均以酸性同工酶为主；组化定位显示POD主要分布在肉质根的周皮、形成层、木射线、木质部导管和肉的初生木质部等的细胞壁附近。

Results showed: in Podocarpus leaves, there is only one midrib, the xylem tracheid of midrib vascular bundle is multi-form, transfusion tissue belongs to Cycas-type and transfusion tracheids are isodiametric, the accessory transfusion tracheids between palisade tissue and sponge tissue are developed; in Nageia leaves, there are plenty of parallel leaves, the xylem tracheids of each vein are relatively simple, transfusion tissue belongs to Taxus-type and transfusion tracheids are longer in longitudinal section than that in transverse section, the accessory transfusion tissue between palisade tissue and sponge tissue is absent.

结果表明：罗汉松属叶1条主脉，主脉维管束木质部管胞发达，转输组织为苏铁型，转输组织管胞等径，栅栏组织和海绵组织之间的副转输组织管胞发达；竹柏属叶多条平行叶脉，维管束木质部管胞相对不发达，转输组织为红豆杉型，转输组织管胞纵向伸长，栅栏组织和海绵组织之间不存在副转输组织。

Primary xylem Xylem derived from the procambium in the young plant.

初生木质部：指幼嫩植物中来源于原形成层的木质部。

Sapwood The outer living xylem cells in a tree trunk, consisting of secondary xylem elements, that are actively involved in water transport and food storage.

边材：由树干近外方的有生命的木质部细胞构成，包括次生木质部、薄壁组织和髓射线。在植物的水分运输及养料储存方面起重要作用。

The study reveals that the secondary xylem of 6 mangrove species of Sonneratia possesses the following characteristics:the diameter of vessel is small,the distribution frequency of vessel is high,the reperforating rate is high,the wall of vessel is thick,the wall of fibre is relatively thick and the wood parenchyma is short or sparse,whish is suitable with the environment.

应用光镜及扫描电镜对生长在热带、亚热带海岸潮间带的 6种海桑属红树植物的次生木质部进行了解剖学研究表明：海桑属 6种红树植物的次生木质部具有导管直径小，导管分布频率高，复孔率高，导管壁厚和纤维壁较厚且具次生加厚，木薄壁组织缺乏或稀少等与环境相适应的特点。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。