1·Tree rings are made of tissue called xylem.
构成年轮的组织被称为木质部。
2·The xylem of ferns only contains tracheids.
蕨类植物的木质部只含有管胞。
3·The xylem of ferns and conifers contains only tracheids.
蕨类植物和针叶树的木质部仅含有管胞。
4·Large proportion of xylem benefit to the water transfer.
叶脉中木质部比重越大，越有利于水分的传输。
5·Wilting toxins can induce to block the xylem of cotton seedling.
致萎毒素可引起棉苗维管束系统堵塞。
6·The bine is comprised by cerebral cortex, xylem and fungous marrow.
茎由皮层。木质部和海绵状的髓组成。
7·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。
8·Secondary xylem consists of pitted vessels, parenchyma fibers and rays.
次生木质部由孔纹导管、 薄壁组织及射线所组成。
9·Blade Angle is strikingly correlated to xylem water potential at midday.
中午木质部水势与叶片角有显著相关性。
10·A system confined to the transport of mineral elements is known as the xylem.
专门用来运输矿物元素的系统称为木质部。
1·But the very end of such a network, the leaf, has a different architecture. Unlike the xylem and phloem, the veins in a leaf cross-link and loop.
但网络的最边缘——叶子，却具有不同的结构，与木质部和韧皮部不同，叶子的纹路交叉并成环。
2·Roads, railways, water and gas mains, sewage pipes and electricity cables all move things around. So do the blood vessels of animals and the sap-carrying xylem and phloem of plants.
他的观点是，在某种程度上二者均由运输物质的网络构成——公路，铁路，水路以及煤气管，污水管还有电缆线都在输送物质，动物血管和植物运输汁液的木质部、韧皮部也是如此。
3·The xylem of ferns and conifers contains only tracheids.
蕨类植物和针叶树的木质部仅含有管胞。
4·In older stems, only the most recent rings of xylem participate in the transport of materials. these make up the sapwood.
在老茎中，仅最新的木质部环参与物质的运输。这些木质部环组成边材。
5·The stele includes all primary tissues derived from the procambium consists of pericycle, phloem and xylem.
中柱包括从原形成层衍生而来的全部初生组织，由中柱鞘、韧质部和木质部组成。