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1.
野豌豆属4种植物种子萌发的积温模型分析   总被引:1,自引:0,他引:1       下载免费PDF全文
以青藏高原野豌豆属窄叶野豌豆(Vicia angustifolia)、山野豌豆(V. amoena)、歪头菜(V. unijuga) 3种野生植物与一种当地栽培植物救荒野豌豆(箭筈豌豆) (V. sativa) ‘兰箭3号’种子为材料, 在5、10、15、20、25及30 ℃下进行萌发实验, 应用种子萌发的积温模型对上述4种植物萌发对温度的响应特征进行了比较分析。结果表明: 1)基于萌发速率(1/Tg)对种子萌发温度最低温Tb值的估计受萌发率(g)的影响较小; 与此不同, 除‘兰箭3号’种子外, 对萌发最高温Tc值的估计, 受到g的显著影响。 这表明种群内所有种子个体萌发的Tb值相对恒定, 但Tc值在有些物种中变异较大; 2)基于重复概率单位回归分析估计的种子萌发Tb值与基于萌发速率估计的值较为接近; 而由此方法估计的Tc值则与萌发率为50%时的估计值较为接近; 3)相比多年生豆科植物歪头菜和山野豌豆, 一年生豆科植物箭筈豌豆‘兰箭3号’与窄叶野豌豆具有相对较低的TbTc值; 4)积温模型可准确地预测休眠破除后豆科植物种子在不同温度条件下的萌发进程。  相似文献   

2.
以3个黑莓(Rubus spp.)品种‘Arapaho’、‘Boysenberry’和‘Kiowa’的成熟果实为实验材料,对果实的形状指标以及硬度进行了测定,并采用石蜡切片技术和扫描电子显微镜分别对3个品种果实的解剖结构以及外果皮及果肉的微形态特征进行了观察;在此基础上,对果实结构与果实硬度的关系进行了探讨.结果表明:品种‘Arapaho’果实的硬度值(0.79 lb·mm-2)大于品种‘Boysenberry’和‘Kiowa’果实的硬度值(0 lb·mm-2):品种‘Arapaho’果实的纵径、横径和单果质量均极显著小于‘Boysenberry’和‘Kiowa’果实.石蜡切片观察结果显示:3个品种的外果皮均较薄且无角质层覆盖,由1~2层表皮细胞组成;其中,品种‘Arapaho’果实的表皮细胞1层、短小且排列紧密,品种‘Boysenberry’果实的表皮细胞2层、细长且排列疏松整齐,品种‘Kiowa’果实的表皮细胞2层、胞壁有褶皱且果面局部凹陷.品种‘Arapaho’的中果皮由大量较完整的薄壁细胞组成并包含没有解体的维管束,而品种‘Boysenberry’和‘Kiowa’的中果皮内均匀分布着解体的薄壁细胞.扫描电镜观察结果显示:品种‘Boysenberry’外果皮具浅波状纹饰、表皮细胞形状不规则,并具稀疏的表皮毛和片状分泌物;品种‘Kiowa’外果皮表面有明显的不规则波纹状纹饰;品种‘Arapaho’外果皮表面纹理紧凑致密、表皮细胞轮廓清晰且形状规则.3个品种的果肉细胞均呈现不同程度的解体现象,但品种‘Arapaho’的果肉细胞中分布有没有解体的胶状物质.根据观察结果推测:黑莓果实果皮和果肉的解剖结构以及微形态特征与其硬度有一定的关系.  相似文献   

3.
灵武长枣正常果及裂果中Ca2+的细胞化学定位研究   总被引:3,自引:0,他引:3  
采用焦锑酸钾沉淀法,对灵武长枣正常果发育过程中的Ca2+及不同开裂度果实中的Ca2+进行细胞化学定位,在透射电镜下观察并比较Ca2+的分布特征和积累规律.结果表明:(1)正常长枣青果期的外果皮细胞及胞间隙中检测到大量的钙沉淀颗粒,而果肉细胞以及叶绿体中很少有钙沉淀颗粒.红果期很多外果皮细胞中钙沉淀颗粒特异性地沿细胞壁呈一圈分布,且越靠近内方的细胞中钙沉淀颗粒越少、越小.果肉细胞中仍无钙沉淀颗粒分布.(2)具轻微开裂的长枣很多外果皮细胞中无钙沉淀颗粒,只有少数细胞中有且集中分布于大液泡中;细胞质沿细胞壁分布,也无钙沉淀颗粒;在果肉细胞中几乎看不到钙沉淀颗粒分布.(3)完全开裂的长枣中钙沉淀颗粒只分布在少数体积较小的外果皮细胞中,而果肉细胞的细胞壁边缘或细胞壁以及胞间隙中分布有大量的钙沉淀颗粒.  相似文献   

4.
以套白色单层纸袋的着色富士系‘天红2号’和短枝富士后代优系4-1-103,以及不着色姊妹系‘冀苹4号’和‘冀苹5号’4个苹果品种(系)为试验材料,利用质构仪整果穿刺和质地多面分析法(texture profile analysis,TPA)测定果实质地,光学显微镜观察果实显微结构,探讨苹果果实质地及其显微结构与果面裂纹的关系,为抗裂纹品种的选育和潜在裂纹机制提供理论依据。结果表明:(1)盛花后132~185 d,‘天红2号’和‘冀苹4号’裂纹率和裂纹指数始终高于4-1-103和‘冀苹5号’,其裂纹主要部位为果肩部。(2)‘天红2号’和‘冀苹4号’的果肉脆裂性、果肉硬度分别显著小于4-1-103和‘冀苹5号’。(3)‘天红2号’和‘冀苹4号’的表皮细胞密度显著小于4-1-103和‘冀苹5号’,其果肉细胞间隙率显著大于4-1-103和‘冀苹5号’,且其角质膜有“V”型凹陷,并发生龟裂,而4-1-103和‘冀苹5号’角质膜完整均一。(4)主成分和灰色关联度分析表明,果肉硬度、果皮果肉硬度比和果肉细胞间隙率是解释裂纹的主要指标。研究发现,果实角质膜完整均一、果肉硬度大、果肉细胞间隙率小的苹果品种不易发生果面裂纹。  相似文献   

5.
以授粉后无距虾脊兰不同发育阶段的蒴果为材料,对果实生长动态进行研究,并用石蜡切片法进行果实结构研究。观察结果表明:无距虾脊兰果实授粉至授粉后40 d生长速度最快。果实由3心皮组成,横切面为6瓣,3瓣有胎座,3瓣无胎座,开裂后6瓣于顶端连接。发育的过程中,果皮细胞层数及果实内外表皮细胞体积不变,果实直径的增加主要来自于细胞平周分裂和中果皮细胞体积的增大。果实成熟时只有少数细胞有细胞壁增厚现象,开裂线的前体细胞细胞壁发生木质化并向不同方向收缩导致果实的开裂。  相似文献   

6.
不同生育期花生叶片蛋白质含量及氮代谢相关酶活性分析   总被引:2,自引:0,他引:2  
以5个珍珠豆型花生(Arachis hypogaea Linn.)品种(系)‘汕E’(‘Shan E’)、‘汕G’(‘Shan G’)、‘TH’、‘TJ’和‘泉花7号’(‘Quanhua No.7’)为研究对象,分析了花针期、结荚期和饱果期花生叶片中可溶性蛋白质含量及硝酸还原酶(NR)、谷氨酰胺合成酶(GS)和谷氨酸脱氢酶(GDH)活性的变化趋势,并比较了5个品种(系)荚果和秆产量的差异。结果表明:在3个生育期内,5个花生品种(系)叶片可溶性蛋白质含量和GDH活性的变化趋势基本一致,而NR和GS活性的变化趋势则有差异。其中,可溶性蛋白质含量均呈"低—高—低"的变化趋势,在结荚期最高;GDH活性均逐渐升高,至饱果期达最高;‘泉花7号’叶片NR活性呈"高—低—高"的变化趋势,而其他4个品种(系)叶片NR活性均逐渐降低;‘汕E’、‘TJ’和‘泉花7号’叶片GS活性呈逐渐降低趋势,而‘汕G’和‘TH’叶片GS活性呈"低—高—低"的变化趋势。总体上看,5个品种(系)中,‘汕G’和‘泉花7号’叶片的可溶性蛋白质含量及NR和GDH活性、‘汕E’叶片的NR和GS活性以及‘TH’叶片的GDH活性均较高。5个品种(系)的2个产量指标(单株荚果鲜质量和单株秆鲜质量)均有明显差异,总体上看,‘汕G’、‘泉花7号’和‘TH’的2个产量指标均较高,而‘汕E’和‘TJ’的2个产量指标均较低。综合分析结果显示:‘汕G’和‘泉花7号’叶片可溶性蛋白质含量及NR和GDH活性均相对较高,其荚果和秆产量也均较高,表明花生荚果和秆产量与不同生育期叶片氮代谢水平有一定关系。  相似文献   

7.
本文叙述了白扁豆荚果的形态发育和组织分化规律。果实的生长曲线略呈单顶型,前期快,中期缓慢,以后干缩变小。在此过程中,果皮的颜色、表面特征和质地也产生有规律的变化。在上述生长发育过程中,果皮的外表皮与下皮形成外果皮,内表皮与其内的4—5层纤维状细胞形成内果皮,两者之间的薄壁组织与维管束组成中果皮。在荚果迅速生长期末,种子各部分结构已基本形成。成熟的种子由外珠被形成的种皮和发育完全的胚组成。由于其果皮内缺乏交叉的厚壁组织,且两缝线处具有两排木质化细胞的封闭层,故成熟时荚果不开裂。根据其荚果的形态发育规律和结构特征对白扁豆的栽培管理提出了一些建议。  相似文献   

8.
以荚果和籽仁生长发育正常的花生品系‘05D610’及其籽仁皱缩变异系‘05D677’为材料,在荚果膨大阶段初期滴加赤霉素(GA,20mg·L~(-1))和脱落酸(ABA,15 mg·L~(-1))处理幼果,检测荚果生长期间幼果或籽仁内源GA、ABA、ZT(玉米素)和IAA(生长素)含量的变化以及荚果和籽仁的生长量特征,以明确激素含量与荚果和籽仁生长发育的关系和‘05D677’籽仁皱缩的原因。结果显示:(1)外源施加GA处理,可显著提高‘05D610’和‘05D677’的内源GA和ZT含量,并推迟内源IAA含量峰值出现的时间,显著提高‘05D610’荚果和籽仁的鲜重、干重,极显著提高了‘05D677’荚果干重。(2)外源施加ABA处理,使‘05D610’内源GA含量显著降低,‘05D677’内源GA和ABA含量显著提高,同时两品系内源IAA含量峰值出现的时间推迟,使‘05D610’和‘05D677’籽仁干重分别显著和极显著提高。研究表明,用适宜浓度外源GA和ABA处理荚果膨大阶段的初期果针,可以调控荚果膨大阶段幼果或者籽仁中内源激素水平,从而提高花生荚果、籽仁产量;荚果膨大阶段内源GA、ABA和ZT含量不足是导致‘05D677’籽仁皱缩的重要原因。  相似文献   

9.
汁胞粒化是柑橘类果实一类普遍的生理失调病害,主要表现为汁胞硬度增加,果实品质降低。为了明确汁胞粒化过程其他果实组织的生理代谢特征,该试验以成熟‘琯溪蜜柚’果实为材料,室温贮藏60 d,测定不同贮藏阶段果实背面维管束汁胞、侧面维管束汁胞、囊衣和果皮总细胞壁物质含量,以及两类汁胞可溶性固形物含量,同时利用透射电子显微镜观察果实背面维管束和侧面维管束细胞超微结构的动态变化。结果显示:(1)贮藏10 d时两类果实维管束的筛管和伴胞次生细胞壁开始明显加厚,韧皮部薄壁细胞线粒体和囊泡数量开始增多,而且次生细胞壁也开始明显加厚;贮藏20 d时两类维管束韧皮部薄壁细胞线粒体和囊泡数量持续增加,而且高尔基体出现(之后消失),同时囊衣和果皮总细胞壁物质含量开始显著提高;贮藏40 d时仅侧面维管束韧皮部薄壁细胞线粒体数量持续增多,侧面维管束汁胞总细胞壁物质含量开始显著升高;贮藏60 d时两类果实维管束次生细胞壁持续加厚,囊衣、果皮和侧面维管束汁胞总细胞壁物质含量均持续显著升高,然而至贮藏期结束背面维管束汁胞总细胞壁物质含量始终无显著变化。(2)贮藏期内囊衣总细胞壁物质含量始终显著高于果皮,而果皮总细胞壁物质含量始终显著高于两类汁胞;贮藏后期侧面维管束汁胞总细胞壁物质含量显著高于背面维管束汁胞。(3)在果实贮藏过程中背面维管束汁胞可溶性固形物含量始终无显著变化,而侧面维管束汁胞可溶性固形物含量从贮藏40 d至贮藏期结束持续显著降低。研究表明,贮藏期柚果实维管束、囊衣和果皮中细胞壁物质代谢的变化早于汁胞;发现果实维管束韧皮部薄壁细胞内线粒体数量增加的同时维管束次生细胞壁明显加厚,在整个贮藏期内侧面维管束汁胞可溶性固形物含量的显著降低伴随着总细胞壁物质含量的显著升高。这些结果可能有助于柑橘类果实粒化机理的全面揭示。  相似文献   

10.
豆科紫藤属Wisteria约有5-6个现生种,间断分布于中国、日本和美国的温带地区,但化石记录表明,该属在新近纪可能广泛分布于捷克、荷兰、格鲁吉亚阿布哈兹、保加利亚、罗马尼亚、俄罗斯远东、日本和中国。因此,研究紫藤属化石有助于深入认识它的早期演化、分类、多样性、古生态和生物地理,其中荚果化石的分类价值和演化意义尤为显著。文中基于对产自山东临朐中中新世山旺组的山旺紫藤W.shanwangensis荚果化石的再观察,并结合紫藤属3个现生种——紫藤W.sinensis、藤萝W.villosa和多花紫藤W.floribunda的荚果发育特征,讨论这些化石的分类、演化、发育和埋藏学意义。结果进一步证明,山旺紫藤荚果化石与国产的2个现生种——紫藤和藤萝的荚果更为相似,呈倒披针形、种子较少和室间缢缩明显。比较而言,日本和美国产的紫藤属现生种——多花紫藤和美国紫藤W.frutescens的荚果呈线形、种子较多和室间缢缩不明显,而且日本中新世和上新世报道的紫藤属荚果化石与多花紫藤的荚果更为相似。然而,中国和日本报道的紫藤属荚果化石迄今都没发现被毛,这与现生种中最原始的美国紫藤的荚果相似,而与东亚紫藤属现生种密被绒毛的荚果形成显著差别。因此,中国、日本和美国的紫藤属种类可能早在中新世就已经发生了形态地理分化,而荚果无毛或许是该属演化过程中一个比较原始的性状;紫藤属现生种荚果在发育的中、后期果壁上具有与纵轴方向成锐角的倾斜纤维纹饰,它们在荚果完全成熟后导致果瓣沿缝线开裂并卷曲,卷曲的果瓣放入水中又能恢复平整。值得注意的是,山旺紫藤荚果化石果壁上也发现了类似的倾斜纤维纹饰,这表明它们在脱落保存时处在发育的中、后期,这一发育时期脱落的荚果更有可能保存为化石记录;山旺紫藤荚果化石果壁的碳质残片中还富含硅藻类,近似于远距直链藻Melosira distans和颗粒直链藻M.granulata这些浮游相的、生活在深水区的优势种。因此,山旺紫藤荚果脱离母体后可能沉积在湖水较深的地方,而且它也可能是在成熟开裂的状态下脱落,瓣片本来卷曲,被短程搬运至湖中,又在湖水的浸泡下恢复平整状态,而后经沉积物掩埋后形成化石。  相似文献   

11.
BACKGROUND AND AIMS: Medicago truncatula has gained much attention as a genomic model species for legume biology, but little is known about the morphology of its pods and seeds. Structural and developmental characteristics of M. truncatula pod walls and seed coats are presented. METHODS: Plants of M. truncatula ecotype A17 were grown under controlled conditions in a greenhouse. Flowers were date-tagged at anthesis, so that pods of known age could be collected. Harvested pods were fixed and sectioned for light microscopy. Structural attributes of pod walls and seed coats were characterized at four time points throughout early to mid-stages of pod development (3, 6, 13 and 20 d post-pollination). KEY RESULTS: Basic features of the pod wall are an exocarp comprised of a single epidermal layer, a mesocarp with seven to 14 layers of parenchyma cells, and an endocarp composed of an inner epidermal cell layer and three to five layers of sclerenchyma cells adjacent to it. Vascular bundles are abundant in the pod wall and include one lateral carpellary bundle, one median carpellary bundle and nine to 12 vascular bundles, all embedded within the mesocarp parenchyma. Seed coat features include an epidermal layer of macrosclereids, a sub-epidermal layer of osteosclereids, and two to five rows of internal parenchyma cells. The hilar region contains the tracheid bar and the chalazal vascular bundle, the latter of which expands to form only two short branches. CONCLUSIONS: This characterization provides a needed understanding of pod structure and development in this model legume, and should facilitate various molecular investigations into legume fruit and seed biology.  相似文献   

12.
KUO  J.; PATE  J. S. 《Annals of botany》1985,55(5):635-647
A mycelium-like network of internal phloem was observed in theinner mesocarp of the lateral pod walls of the fruit of certaingenotypes of cowpea [Vigna unguiculata (L.) Walp.] In the cultivarVita 3, the network consists of single, or rarely double, strandsof sieve elements and associated phloem parenchyma, orientedmainly parallel with the fibres of the adjacent endocarp, andstretching marginally beyond the sheets of fibres to connectabove and below with the outermost phloem of the longitudinalstrands of the dorsal and ventral sutures of the fruit. Theinternal phloem network does not relate conformationally to,or interconnect with the conventional (xylem+phloem) vasculatureof the mid mesocarp of the pod wall. In Vita 3, sieve elementsdifferentiate in the internal phloem after those in the majorveins of the pod, but before the presumptive endocarp fibrescommence wall thickening. The pod walls of twenty-one otherspecies of legumes proved negative for internal phloem, whileof nine varied genotypes of cowpea examined, six proved positive,three negative for the trait. Presence of internal phloem incowpea is not always associated with presence of endocarp fibresor necessarily with large fruits with large seeds. Possiblefunctions suggested for the phloem network are to provide assimilatesfor fibre wall thickening or to transport solutes to or fromsites of temporary storage in the fleshy inner layers of thepod wall. Internal phloem, legume fruit, translocation, mesocarp, pod wall, Vigna unguiculata, cowpea  相似文献   

13.
Ditylenchus africanus entered the immature pegs and pods of peanut (Arachis hypogaea cv. Sellie) at the peg-connection and subsequently invaded the parenchymatous regions of the hull exocarp and endocarp, and eventually the seed testa. The nematode caused malformations of the cells of infected tissues, cell wall breakage, and cell collapse. The damage appeared to be due to enzymatic activity. In some testae the entire parenchyma region, which aids in protection of the seed, was destroyed. In immature pods, the nematodes moved across the fibrous region of the mesocarp into the hull endocarp. In mature pods, however, the fibrous mesocarp of the hull was lignified and apparently was a barrier to penetration of the inner pod tissues. In late-harvested pods, increased numbers of eggs and anhydrobiotes were found in the hull tissues, and eggs in the seed testa, suggesting the onset of winter survival mechanisms of the nematode.  相似文献   

14.

Palm fruits show great structural complexity, and in-depth studies of their development are still scarce. This work aimed to define the developmental stages of the fruit of the neotropical palm Butia capitata and to characterize the ontogenesis of its pericarp. Biometric, anatomical, and histochemical evaluations were performed on pistillate flowers and developing fruits. The whole fruit develops in three phases: (I) histogenesis (up to 42 days after anthesis – DAA), when the topographic regions of the pericarp are defined; (II) pyrene maturation (42 to 70 DAA), when the sclerified zone of the pericarp is established; and (III) mesocarp maturation (70 to 84 DAA), when reserve deposition is completed. During pericarp ontogenesis (i) the outer epidermis and the outer mesophyll of the ovary give origin to the exocarp (secretory epidermis, collenchyma, parenchyma, sclerenchyma, and vascular bundles); (ii) the median ovarian mesophyll develops into the mesocarp, with two distinct topographical regions; (iii) the inner ovarian epidermis originates the endocarp; and in the micropylar region, it differentiates into the germination pore plate, a structure that protects the embryo and controls germination. (iv) Most of the inner region of the mesocarp fuses with the endocarp and, both lignified, give rise to the stony pyrene; (v) in the other regions of the mesocarp, carbohydrates and lipids are accumulated in a parenchyma permeated with fiber and vascular bundles. The development of the B. capitata pericarp presents high complexity and a pattern not yet reported for Arecaceae, which supports the adoption of the Butia-type pyrenarium fruit class.

  相似文献   

15.
An exocarp sensu stricto develops from the outer epidermis of the ovary wall. At maturity it comprises extensively radially elongated palisade-like parenchyma cellS. Besides having an outer cuticle, the outer tangential and outer parts of the radial cell walls of these cells are strongly cutinized. Large, permanently open stomata and saucer-shaped depressions also characterize the exocarp. The mature mesocarp sensu stricto consists of secondarily thickened parenchyma and brachysclereidS. An abundance of tanniniferous deposits and crystals, as well as secretory ducts associated with the vascular bundles also form part of the mature mesocarp. Derivatives of the inner epidermis of the ovary wall differentiate into the stratified endocarp sensu stricto. At maturity this comprises consecutive layers of macrosclereids, osteosclereids (typified by a capitate part and cell wall flutes), brachysclereids, and crystalliferous sclereidS. Pericarp structure is related to its taxonomic significance and the possible role of micromorphological characters in the survival strategy of Ozoroa paniculosa. It is shown that ontogenetic studies contribute to the precise interpretation of previously described cell layers, ensuring that homologous tissues are compared in different taxa.  相似文献   

16.
龙眼果皮形态结构比较观察及其与果实耐贮运的关系   总被引:7,自引:0,他引:7  
林河通  席玙芳  陈绍军  陈锦权 《广西植物》2002,22(5):413-413,424,T004
比较了福建省 1 0个主栽龙眼品种果实的果皮形态和结构 ,结果表明 :不同品种在果皮厚度、外果皮表面颜色、龟状纹、放射线、瘤状突、刺毛、外果皮皮孔、周皮层厚度、栓质层厚度和连续性、中果皮薄壁组织细胞排列、石细胞大小、含量、排列和分布 ,维管束发达状况、排列和分布 ,内果皮表皮细胞排列和角蜡质层厚度等方面均存在着明显差异。风梨味、东壁、油潭本、乌龙岭、红核子、蕉眼龙眼果皮厚 ,外果皮表面瘤状突和剌毛多 ,外果皮周皮层、栓质层厚且连续性好 ,中果皮石细胞 (团 )含量多且排列紧密 ,分布在中果皮外侧且在中果皮中所占比例大 ,维管束发达且排列有序 ,内果皮角蜡质层厚 ;这些品种果实耐贮运、抗病性强。而水涨、赤壳、福眼、普明庵龙眼果皮薄 ,外果皮周皮层薄、栓质层不发达 ,中果皮石细胞 (团 )含量少、分布分散 ,维管束不发达 ,薄壁组织细胞胞间隙大 ,皮孔间隙大、皮孔通道与中果皮组织细胞间隙相通 ;这些品种的果实不耐贮运、抗病性弱。讨论了龙眼外果皮表面主色为褐色和内果皮比外果皮更容易褐变的解剖学原因及龙眼果皮形态结构与果实耐贮运的关系。  相似文献   

17.
Development and structure of the pericarp of Lannea discolor (Sonder) Engl.(Anacardiaceae). The exocarp develops from the outer epidermis and subepidermal, parenchymatous cell layers of the ovary wall. A parenchymatous zone with secretory cavities more or less delimits the exocarp internally. The inner part of the parenchymatous mesocarp is tanniniferous. The parenchymatous transition zone between mesocarp and sclercnchymatous endocarp or sderocarp, contains vascular tissue. The inner endocarp and operculum develop from the inner epidermis and subepidermal parenchyma of the ovary wall, while the outer endocarp develops from the parenchymatous zone with procambium strandS. Comparing the pericarp of L.discolor with those of Sclerocarya birrea subsp. caffra and Rhus lancea , the close affinity with Sclerocarya birrea subsp. caffra is evident.  相似文献   

18.
核桃果皮的发育解剖学研究   总被引:6,自引:0,他引:6  
核桃果皮的发育过程可分为3个阶段,发育时期:中、内三层果皮的界线不清,维管束处于发育初期;发育中期:随着中果皮最外侧两层石细胞的出现和薄壁组织细胞体积的迅速扩大以及维管束轮数的增加,使三层果皮具较明显的界面,发育后期:中果皮的维管束递增到4-5轮,  相似文献   

19.
The main product of Camellia oleifera is edible oil made from the seeds, but huge quantities of agro-waste are produced in the form of shells. The primary components of C. oleifera fruit shell are cellulose, hemicellulose, and lignin, which probably make it a good eco-friendly non-wood material. Understanding the structure of the shell is however a prerequisite to making full use of it. The anatomical structure of C. oleifera fruit shells was investigated from macroscopic to ultrastructural scale by stereoscopic, optical, and scanning electron microscopy. The main cell morphology in the different parts of the shell was observed and measured using the tissue segregation method. The density of the cross section of the shell was also obtained using an X-ray CT scanner to check the change in texture. The C. oleifera fruit pericarp was made up of exocarp, mesocarp, and endocarp. The main types of exocarp cells were stone cells, spiral vessels, and parenchyma cells. The mesocarp accounted for most of the shell and consisted of parenchyma, tracheids, and some stone cells. The endocarp was basically made up of cells with a thickened cell wall that were modified tracheid or parenchyma cells with secondary wall thickening. The most important ultrastructure in these cells was the pits in the cell wall of stone and vessel cells that give the shell a conducting, mechanical, and protective role. The density of the shell gradually decreased from exocarp to endocarp. Tracheid cells are one of the main cell types in the shell, but their low slenderness (length to width) ratio makes them unsuitable for the manufacture of paper. Further research should be conducted on composite shell-plastic panels (or other reinforced materials) to make better use of this agro-waste.  相似文献   

20.
Cross- and partially cross-pollinated capitula of Cichorium intybus (Compositae, Lactuceae) were examined for a study of normal and seedless fruit development respectively. Embryos develop according to the Asterad pattern, and the free-nuclear endosperm becomes cellular 15–17 hrs after pollination. A zone of disorganized cellular material surrounds the embryo sac at anthesis, and, in normal achenes, this zone expands as the seed develops. Initially the developing seed elongates and comes into contact with the top of the ovary by 48 hrs. In contrast to this pattern, the ovule in developing seedless achenes degenerates within 72 hrs. Irregularities, such as an abnormally proliferating endothelium, embryo formation without endosperm, and endosperm formation without an embryo often accompany this degeneration. Differentiation of the pericarp in seeded achenes begins between 48 and 72 hrs, starting at the apex and proceeding basipetally; in seedless fruits the process is similar though initiated somewhat later. The normal pericarp at maturity exhibits a pigmented exocarp, a broad mesocarp of thick-walled lignified cells, and a tenuous endocarp. In seedless achenes the fruit coat is similar except that the exocarp is colorless and the cells of the mesocarp are relatively small.  相似文献   

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