维管束

The result showed that in Beijing there are 1505 species of wild vascular bundle, of which there are 3 species protected in the level of state and 98 species protected in the level of area and 36 species threatened and 199 species endemism. These species mainly distribute in Mentougou, Miyun, Yanqing, Huairou, Haidian, Fangshan, Changpin.

结果表明：北京地区野生维管植物共计1505种，国家重点保护野生维管束植物3种，北京市保护野生维管束植物98种，受危胁野生维管束植物36种，中国特有野生维管束植物199种，且主要分布于门头沟区、密云县、延庆县、怀柔区、海淀区、房山区、昌平区。

Consisted of single, double vascular bundle, transition types between them, but given priority to double vascular bundle; the epidermal cell consisted of cutin layer; the hypodermis consisted of typical two-layer of parenchyma cells arranged continuously or discontinuously.

云南松针叶的维管束以双维管束为主，同时亦有单维管束以及介于单、双维管束之间的过渡类型；皮下层为典型的二型皮下层；表皮层的角质层明显；树脂道多为典型的外生型。

The midrib-bundl es have be found with follow possible evolutionary trends: amphicribral bundle- almost-amphicriral bundle collateral bundle.

讨论 了中脉维管束类型可能的演化趋势：周韧维管束→近周韧维管束→下韧维管束。

According to the arra ngem ent of phloem and xylem, shape of xylem and the Arranging way of xylem rays, the midrib-bundles were divided into five forms :(1) amphicribral round bundle;(2 ) pinnate-ray amphicribral reniform bundle;(3) fan-ray amphicribral reniform b undle;(4) almost-amphicribral bundle;(5) collateral bundle.

根据中脉维管束结构特点：木质部与韧皮部的位置，木质部的形状，木射线排列的方式，可分为5个类型：（1）圆形周韧维管束；（2）羽线肾形周韧维管束；（3）扇线肾形周韧维管束；（4）近周韧维管束；（5）下韧维管束。

They all have the typical structure of leaf of C4 plant, but out of the ordinary is that the structure of the midrib is alike the parallel veins and there is a layer of fiber cells between the phloem and the bundle-sheath of vein in the midrib and big parallel veins while the outer wall of the bulliform cells is less cuticularized.

摘 要：以7个杂交狗牙根品种的叶片进行解剖研究，结果表明，各品种均具禾本科 C4植物叶片典型结构，其独特处是：中脉结构与平行脉相似；中脉维管束、平行脉大维管束的维管束鞘内侧韧皮部外有一层纤维细胞；泡状细胞外壁很少角化。

The other six bundles,which were nearly round,continuously expanded towards the top,of which three bundles entered the ovary wall after extended into the locule region to become the carpellary dorsal bundles which finally entered the style,of which the other three moved to center to become the placenta vascular bundles which were absent at the top of the locule.

另6枚近圆束形的维管束一直在中央向上延伸，进入子房室区后，其中3枚进入子房壁，成为3束心皮背束，最后3束心皮背束进入花柱成为花柱维管束，另3枚聚向中央，成为胎座维管束，胎座维管束至子房室顶部时消失。

The results showed that rice straw growth and fascicular alteration interacted when water was deficient. It not only affected the transportation of nutritious substance from rhizine and leaf to kernel, but also led to the decrease of agronomic characters and yield. 4 ecotypes of rice vascular bund...

结果表明：水分不足对稻秆及秆中维管束的影响是相互的：稻秆的发育情况影响了维管束变化，同时维管束的变化影响了稻秆的发育，最终影响营养物质从根部、叶部向籽粒运输，从而使结粒数、稔实率、千粒重、产量下降。4种生态型水稻维管束系统与一次及高次枝梗数目、结粒数、千粒重等有类似的相关性，而且水分不足时反应出相同的结果，说明土壤水分对维管束系统的分化有很大的影响，水分不足将使维管束面积变小，维管束比增大，从而使产量变小。

The area and number of heavy tracheae for a SVB, mean area of a tracheae for a SVB, the area and number of tracheae for all SVB had a significantly positive correlation with PGG on CMS lines, while the area of a tracheae for a SVB which has tracheaes, the area for a SVB, volume, weight, water potential had a negative correlation with PGG on CMS lines.

不育系种子裂颖率与浆片单个小维管束的导管面积和数目、单个小维管束平均单个导管面积、整个小维管束的导管面积和数目呈极显著负相关，与浆片单个导管未退化小维管束单个导管面积、单个小维管束面积、体积、重量、水势呈显著正相关。

Experimental results show that there are existing some indifferent mechanisms to the pollen sterilization of the Ms types: during the period of single nucleic to three nucleic pollen cell,we observed that the cell of xylem and phloem in anther septum abnormally developed,also the cell in the sheath of vascular bundle,smaller and arranged irregularly; the metabolic block developed too,es...

结果表明，不育类型的花粉败育有着一些共同的机理：在花粉单核期至三核期可见到花药隔维管束的木质部及韧皮部细胞发育较差，维管束鞘细胞发育不良，体积较小，排列紊乱；在单核花粉期至三核花粉期均发生物质代谢障碍，特别在花药部位尤为明显；由于维管束发育不良和花药物质代谢障碍，导致了花粉缺乏营养而败育。

Here are the results: there are no clear difference in the length and width of leaf epidermis stomatal apparatus, stoma density and vascular bundle area in 1st internode below the ear between cold and warm type wheat. The vascular bundle area in 2nd internode below the ear of cold type wheat is obvious smaller than warm type wheat's. There are clear difference in the vascular bundle number in unit transverse area of 1st internode and 2nd internode below the ear and the rate of the total area of vascular bundle and the transverse area of wheat stem between cold and warm type wheat.

研究表明，冷、暖型小麦叶表皮气孔器的长度和宽度、气孔密度、穗下节间中维管束面积均无显著差异；冷型小麦倒二节间中维管束面积明显小于暖型小麦；冷、暖型小麦穗下节间、倒二节间单位横截面积中维管束数目、维管束总面积占茎横截面积的百分率均有显著差异。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。