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.

在根的初生結(jié)構(gòu)中，其初生木質(zhì)部為二原型真人批批120分钟，木質(zhì)部及韌皮部的發(fā)育均為外始式。

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.

結(jié)果表明：羅漢松屬葉1條主脈，主脈維管束木質(zhì)部管胞發(fā)達(dá)最新2021自拍自产视频，轉(zhuǎn)輸組織為蘇鐵型，轉(zhuǎn)輸組織管胞等徑国内精品视频一区二区，柵欄組織和海綿組織之間的副轉(zhuǎn)輸組織管胞發(fā)達(dá)黑人和黑人一级毛片；竹柏屬葉多條平行葉脈色就是色综合网，維管束木質(zhì)部管胞相對不發(fā)達(dá)，轉(zhuǎn)輸組織為紅豆杉型，轉(zhuǎn)輸組織管胞縱向伸長黄片在线高清免费观看，柵欄組織和海綿組織之間不存在副轉(zhuǎn)輸組織AAA性爱片。

The existence of nuclei in mature xylem cells is a symbol of primitiveness, for such nuclei all exist in secondary xylem of families or genera which are in the rather primitive stage of development in plant systems.

成熟木材細(xì)胞中的細(xì)胞核是一個原始的特征6080午夜三级中文在线观看，均出現(xiàn)在植物系統(tǒng)發(fā)育上較為原始的科屬木材中男女啪啪真实无遮挡免费动态图。

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

初生木質(zhì)部：指幼嫩植物中來源于原形成層的木質(zhì)部。

This indicated that arrowleaf saltbush was able to change the ultrafiltration characteristics of its root system and reduce radial reflection coefficient of the root, thus lowering the risk of higher xylem tension leading to xylem cavitation and able to reduce salt absorption to avoid damage of salt over-accumulation to the plant.

說明三角葉濱藜在鹽脅迫下一方面通過改變根系的超濾特性国产激情在线一区，降低根系徑向反射系數(shù)來防止木質(zhì)部拉力過大導(dǎo)致的木質(zhì)部空化的危險日韩成人网址播放器在线播放免费，另一方面通過減少對鹽分的吸收來避免鹽分過多積累對植株的傷害。

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.

邊材：由樹干近外方的有生命的木質(zhì)部細(xì)胞構(gòu)成，包括次生木質(zhì)部一页专区、薄壁組織和髓射線黄色视频直接进。在植物的水分運輸及養(yǎng)料儲存方面起重要作用国产一级激情免费视频。

The exterior of root system of Melilotodes in adult period mostly covers a flat thick"velamen"in the course of growth and development. The polysaccharide in the interior of root system lies in secondary phloem and secondary xylem and xylem ray ,which distributes uniformity.

在生長發(fā)育過程中，生長5年的扁蓿豆成株大部分根系外面覆蓋了一層厚厚的"根被"，其根系內(nèi)部多糖存在于次生韌皮部和次生木質(zhì)部及木質(zhì)射線中，顆粒在細(xì)胞中分布較均勻欧美一级专区。

The exterior of root system of alfalfa in adult period hasn't velamen. The polysaccharide in the interior of root system lies in partial secondary phloem and xylem ray of secondary xylem, which doesn't distribute uniformity.

這與苜蓿有差別，苜蓿成株根系外側(cè)沒有"根被"网址在线观看国产日韩视频，且根系內(nèi)部多糖存在于部分次生韌皮部和次生木質(zhì)部的木質(zhì)射線中，分布不均勻。

Deep research and comparison show that, besides the centrarch xylem, H. reflexa has G-type tracheids. Upon and between the annular secondary thickenings, the lignified layer of secondary cell wall bears irregular simple perforations of small diameter and high density. So these perforations have the characters of S-type tracheids. The robust xylem strand and dense perforations indicate the strengthened water-conducting capacity.

深入的研究和比較表明H.reflexa的木質(zhì)部除為心始式外，管胞為G-型，次生壁的木質(zhì)化層具有不規(guī)則的簡單穿孔95久久精品无码一区二区，穿孔直徑小全免费A级毛片免费看69，密度大99re视频这里只有精品，分布在環(huán)紋次生加厚帶和其間免费观看黄色的视频在线看，兼有S-型管胞穿孔的特征91主播；粗壯的木質(zhì)部束和密集的穿孔表明較強的輸導(dǎo)能力。

In addition, the repair method can also be filled tree holes, stuffing is best to use small gravel and cement mixture to be compacted filler, filler to strengthen the connection with the xylem, inside the cave can be a number of electroplating nails nails, holes dug in on both sides 4 centimeters deep groove at the bottom of filler from the start, each 20-25 cm for the layer, using linoleum separated from each floor should be inclined slightly outward to facilitate drainage, the edge should not exceed xylem, so that cambium in the formation of callus on it.

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