The rhizome of cultivated rheum in qunjia of qinghai province , was picked broke into cortex , phloem , xylem and marrow , the content of cu , zn , fe , mn , co , ni elements of the every tissue was analyzed by atom absorb spectrum 采集青海群加地区种植大黄根茎，分为皮层、韧皮部、木质部和髓部等四部分，采用原子吸收光谱法分别测试了其不同组织中铜、锌、铁、锰、钻、镍等元素含量。
The storage protein accumulated in large quantity in the vegetative organs of swietenia macrophylla at the period near leaf fall and in the leaf - fall period with terminal branchlets much richer in the storge protein than trunks and roots 在树木年生长周期的后期， 18kda和zikda蛋白质分布于枝条、树干、大根和小根，大量积累在这些器官的次生韧皮部和末端小枝及小根的次生木质部中。
We have observed the following characteristics of anatomical structure and development : ( 1 ) the primary roots belong to archetype and the lateral roots occur in the position toward the xylem of the vascular cylinder ; ( 2 ) the root endodermis consists of thicken casparian strips , and there are from two lo four layers parenchyma cells near the pericycle ; ( 3 ) the pith and resins canals are absent in the toots ; ( 4 ) secondary structure occurs in the root hair zone , and vascular cambium is formed from the parenchyma cells between the primary xylem and primary phloem ; ( 5 ) tanning materials are abundant in pericycle cells and phelloderm cells ; ( 6 ) sclereids are found in secondary phloem , and rays are rather rich in secondary xylem 结果表明：气生不定根具有以下结构特征和发育特点： ( 1 )根为二原型，侧根正对着木质部发生； ( 2 )幼根内皮层细胞具凯氏带加厚，维管柱内紧挨中柱鞘内侧具有2 ~ 4层大型薄壁细胞； ( 2 )根中无髓和树脂道； ( 4 )次生结构发生于根毛区，维管形成层由初生木质部和初生韧皮部之间的薄壁细胞转化形成； ( 5 )中柱鞘和栓内层细胞富含单宁类物质； ( 6 )次生韧皮部有石细胞，次生木质部射线发达。
Thickness of upper and lower epidermis of leaves , width of xylem and phloem of annual and biennial branches , ratio of late wood to early wood , periderm thickness of biennial branches , and length of xylem ray present decreasing trends with latitude ascending ; while ratio of palisade tissue to spongy tissue , epidermis thickness of annual branches , and cortex thickness of biennial branches show unobvious variations with latitude increasing 叶的上下表皮厚度、 1和2年生枝木质部及韧皮部宽度、晚材早材比值、 2年生枝的周皮厚度、木射线长等均随纬度升高而呈下降趋势；而叶的栅栏组织和海绵组织比值、 1年生枝表皮厚度、 2年生皮层厚度等解剖结构随纬度变化没有明显规律。
There is great difference between the content of carotenes of different parts in different varieties : the content of carotenes of phloem is ' higher than xylem ' s to a great extent , and the results showed a descending trend of the content of carotenes from the top of carrot to lower parts 所以对这些品种建议提早采收，以便胡萝卜素含量保持在较高的水平。胡萝卜次生韧皮部中的胡萝卜素含量极显著的高于次生木质部，胡萝卜肉质根中自上而下胡萝素含量呈现递减的趋势，胡萝卜素在胡萝卜中主要分布于次生韧皮部和肉质根的上部。
The secondary phloem parenchyma cells and secondary phloem ray parenchyma cells were the preferential sites for protein storage to the xylem parenchyma cells whereas a large amount of vegetative storage proteins was present in xylem , especially in the primary xylem and the inner secondary xylem of the extended stems 营养贮藏蛋白质优先在次生韧皮部的韧皮薄壁细胞和韧皮射线薄壁细胞中积累，在新梢伸长生长停止后，新梢基部茎的木质部中也积累了相当数量的营养贮藏蛋白质，主要分布在初生木质部和内侧次生木质部的各种生活的薄壁细胞中。
More anthraquinone compounds was distributed in pith ray cells and the tissues of mature stem suchas bundle sheaths in large - scale vascular bundle , primary phloem and primary xylem than that in young stem . [ conclusion ] the distribution of anthraquinone compounds in the stem was of multilocus 结果随着茎的不断成熟，在茎的表皮、近表皮的1 ~ 2层皮层细胞及较内部皮层中，不同程度地增加贮藏和积累了一定数量的蒽醌类化合物，成为茎外部贮藏和积累蒽醌共化合物的主要结构部位成热茎大型维管束的维管束鞘、初生韧皮部、初生木质部等组织和髓射线细胞分布了比幼茎多的蒽醌类化合物。
