Development and structure of the drupe in Sclerocarya birrea (Richard) Hochst. subsp. caffra Kokwaro (Anacardiaceae), with special reference to the pericarp and the operculum

The development and structure of the exo-, meso- and endocarp of the drupe of Sclerocarya birrea subsp. caffra were examined. The mature exocarp comprises the outer epidermis with stomata and lenticels, subepidermal collenchyma and parenchymatous layers with secretory canals. This exocarp sensu lato develops from the outer epidermis and the outer layers of the ovary wall. The fleshy parenchymatous mesocarp or sarcocarp also contains secretory tissue. The mesocarp develops after endocarp differentiation and lignification. The developmental sequence within the pericarp corresponds to the general pattern in drupes. The endocarp or sclerocarp, which is not stratified, consisting mainly of brachysclereids, fibres and vascular elements, develops from the inner epidermis and adjacent tissue of the young ovary wall including the procambium strands. The operculum represents a well-defined part of the endocarp. Early in its development a parenchymatous zone already clearly demarcates the operculum. The literature on the pericarp of the Anacardiaceae drupe is discussed to establish the diagnostic value of these morphological characteristics for future taxonomic studies.     

Development and structure of the pericarp of Lannea discolor (Sonder) Engl.(Anacardiaceae)

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.     

The ontogeny and structure of the pericarp and seed-coat of Harpephyllum caffrum Bernh. ex Krauss (Anacardiaceae)

The exocarp sensu lato , which develops from the outer epidermis and adjacent parenchyma of the ovary wall, consists of collenchyma cells with a stomatous epidermis. The fleshy, parenchymatous mesocarp or sarcocarp develops after endocarp differentiation. The endocarp is partly spongy and partly woody. The spongy endocarp contains most of the vascular tissue and fills the cavities and grooves of the intricately sculptured outer woody endocarp. The inner woody endocarp and adjacent woody, endocarpal operculum develop from the inner epidermis and subepidermal parenchyma of the ovary wall. The bitegmic, anatropous ovule develops into a derived, exalbuminous seed with an undifferentiated seed-coat. An extensive chalaza, extensive hypostase sensu lato and the raphe are important in the development of the seed-coat. The pericarp and seed-coat of H. caffrum is compared with those of Sclerocarya birrea subsp. caffra and Lannea discolor . The close phylogenetic relationship of these three species of the Spondieae is reaffirmed. The marked similarities in pericarp and seed structure between H. caffrum and species of the genus Spondias are noted.     

The Generic Position of Protorhus namaquensis Sprague (Anacardiaceae): Evidence from Fruit Structure

In Protorhus namaquensis the outer epidermis of the ovary formsthe exocarp. At maturity it is uniseriate and consists of palisade-likeparenchyma cells and modified stomata (MS). A cuticle, extensivecutinization of the outer cell walls and starch also characterizethe exocarp. The mesocarp develops from the ground tissue ofthe ovary wall and includes an outer zone of large-celled tanniniferousparenchyma, secretory ducts associated with some of the vascularbundles, prismatic crystals of calcium oxalate and brachysclereids.The inner epidermis of the ovary undergoes successive periclinaldivisions whose derivatives form the mature endocarp. It isstratified and tetraseriate, comprising successive layers (frommesocarp inwards) of crystalliferous cells, brachysclereids,osteosclereids and macrosclereids. The morphology of the femaleflower, and the fruit structure of P. namaquensis are comparedwith that of P. longifolia (lectotype of the genus and onlyother African species) and species of Ozoroa. We present abundantevidence that P. namaquensis should be associated with somemembers of the genus Ozoroa , rather than with P. longifolia.The new combination, Ozoroa namaquensis (Sprague) Von Teichman& Van Wyk, is proposed. Characters of the perianth and pericarp,inter alia the occlusion of the pores of most MS, are consideredadaptations of the species to its harsh semi-desert habitat.Copyright1994, 1999 Academic Press Anacardiaceae, Protorhus namaquensis, Ozoroa namaquensis, pericarp, fruit, flower, modified stomata, ontogeny, histochemistry, cutin     

Seed coat development, anatomy and scanning electron microscopy of Harpagophytum procumbens (Devil's Claw), Pedaliaceae

Seed coat development of Harpagophytum procumbens (Devil's Claw) and the possible role of the mature seed coat in seed dormancy were studied by light microscopy (LM), transmission electron microscopy (TEM) and environmental scanning electron microscopy (ESEM). Very young ovules of H. procumbens have a single thick integument consisting of densely packed thin-walled parenchyma cells that are uniform in shape and size. During later developmental stages the parenchyma cells differentiate into 4 different zones. Zone 1 is the multi-layered inner epidermis of the single integument that eventually develops into a tough impenetrable covering that tightly encloses the embryo. The inner epidermis is delineated on the inside by a few layers of collapsed remnant endosperm cell wall layers and on the outside by remnant cell wall layers of zone 2, also called the middle layer. Together with the inner epidermis these remnant cell wall layers from collapsed cells may contribute towards seed coat impermeability. Zone 2 underneath the inner epidermis consists of large thin-walled parenchyma cells. Zone 3 is the sub-epidermal layers underneath the outer epidermis referred to as a hypodermis and zone 4 is the single outer seed coat epidermal layer. Both zones 3 and 4 develop unusual secondary wall thickenings. The primary cell walls of the outer epidermis and hypodermis disintegrated during the final stages of seed maturation, leaving only a scaffold of these secondary cell wall thickenings. In the mature seed coat the outer fibrillar seed coat consists of the outer epidermis and hypodermis and separates easily to reveal the dense, smooth inner epidermis of the seed coat. Outer epidermal and hypodermal wall thickenings develop over primary pit fields and arise from the deposition of secondary cell wall material in the form of alternative electron dense and electron lucent layers. ESEM studies showed that the outer epidermal and hypodermal seed coat layers are exceptionally hygroscopic. At 100% relative humidity within the ESEM chamber, drops of water readily condense on the seed surface and react in various ways with the seed coat components, resulting in the swelling and expansion of the wall thickenings. The flexible fibrous outer seed coat epidermis and hypodermis may enhance soil seed contact and retention of water, while the inner seed coat epidermis maintains structural and perhaps chemical seed dormancy due to the possible presence of inhibitors.     

山茱萸果皮的解剖学研究

本文报导了山茱萸果皮的解剖学研究结果.外果皮由一层表皮细胞构成.中果皮外方为3-4(5)层厚角组织细胞,这些细胞通常含有单宁;其内方包含薄壁细胞、单宁细胞和8束维管束.单宁细胞成团或零星分布于薄璧细胞中,前者的体积明显大于后者.单宁细胞的单宁与多糖结合在一起.维管束含有环纹、螺纹、梯纹、网纹及孔纹管胞,还有少数散生的纤维.内果皮高度木质化,主要由多种形状的石细胞组成,其间分布了肉眼可见、排列成环状的异细胞,偶见少数生活石细胞及薄壁细胞.内果皮有3束维管束.     

Fruit structure of the southern African species of Apodytes Meyer ex Arn. (Icacinaceae)

Fruit development and structure of three southern African species of Apodytes were examined by light and scanning electron microscopy. These are A. dimidiata E. Meyer ex Arn. subsp. dimidiata and two undescribed species designated Apodytes sp. nov. A and B. Fruits are unilaterally developed drupes, ellipsoid and somewhat compressed laterally, with a large succulent appendage. Appendages of A. dimidiata and Apodytes sp. nov. A are predominantly red, whereas those of Apodytes sp. nov. B are a pale translucent green. In all three species the appendages turn black in old fruit. The exocarp is uniseriate and develops solely from the outer epidermis of the ovary wall. The mesocarp is partly parenchymatous, with vascular bundles and cells containing druse crystals of calcium oxalate, and partly lignified (= stone). The uniseriate endocarp s. sir. develops from the inner epidermis of the ovary wall. In a sense the fruit of Apodytes is a composite of parts comparable to a nut (alternatively an achene) and a fleshy drupe. The drupaceous part (fleshy appendage) is a derived structure which develops from the sterile carpel of a reduced locule. We suggest that the fleshy appendage originates as an indicator of seed/fruit maturity, and to attract avian dispersers. Limited field observations support the idea that the red/black appendages of A. dimidiata and Apodytes sp. nov. A also serve as an edible reward for birds. Dispersal of fruit of Apodytes sp. nov. B, with its rather inconspicuously coloured appendage, may be dependent on a specialized fruit/frugivore relationship.     

Development and structure of the seed-coat of Lannea discolor (Sonder) Engl. (Anacardiaceae)

VON TEICHMAN, I., 1988. The development and structure of the seed-coat of Lannea discolor (Sonder) Engl. (Anacardiaceae). The bitegmic, anatropous ovule contains a group of nucellar cells with slightly thickened and intensively staining cell walls. Besides this hypostase sensu stricto, the nucellus cells in the chalaza become tanniniferous. This tanniniferous chalazal-nucellar tissue is intially plate-like. It is referred to as the hypostase sensu lato. The latter and the chalaza enlarge significantly. The raphe, extensive chalaza and well-developed cup-like hypostase sensu lato play an important role in the development of the seed-coat. The inner, tanniniferous epidermis of the inner integument persists in parts of the mature seed-coat. The outer, distinctly tanniniferous epidermis of the outer integument shows in the mature seed-coat a degree of secondary wall thickening. This undifferentiated type of seed-coat of L. discolor (tribe Spondieae) is remarkably similar to that of Camnosperma minor (tribe Rhoideae), both also showing tendency towards the exotestal type. In the Rhoideae the endotestal, i.e. differentiated type, of seed-coat is also present. The exalbuminous seed of L. discolor represents a derived and advanced type.     

Fruit structure of Amborella trichopoda (Amborellaceae)

The indehiscent fruitlets of the apparently basalmost extant angiosperm, Amborella trichopoda, have a pericarp that is differentiated into five zones, a thin one‐cell‐layered skin (exocarp), a thick fleshy zone of 25–35 cell layers (outer mesocarp), a thick, large‐celled sclerenchymatous zone (unlignified) of 6–18 cell layers (middle mesocarp), a single cell layer with thin‐walled (silicified?) cells (inner mesocarp), and a 2–4‐cell‐layered, small‐celled sclerenchymatous zone (unlignified) derived from the inner epidermis (endocarp). The border between inner and outer mesocarp is not even but the inner mesocarp forms a network of ridges and pits; the ridges support the vascular bundles, which are situated in the outer mesocarp. In accordance with previous observations by Bailey & Swamy, no ethereal oil cells were observed in the pericarp; however, lysigenous cavities as mentioned by these authors are also lacking; they seem to be an artefact caused by re‐expanding dried fruits. The seed coat is not sclerified. The fruitlets of Amborella differ from externally similar fruits or fruitlets in other basal angiosperms, such as Austrobaileyales or Laurales, in their histology. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 148 , 265–274.     

Structure and ontogeny of Swartzia langsdorffii (Leguminosae) pericarp

In order to elucidate the position of the Swartzieae in Leguminosae, Swartzia langsdorffii was chosen as a representative of this tribe type genus and subjected to structural studies of immature ovaries (in the floral bud and flowers) and developing and mature fruits. The external epidermis of the ovary is characterized by one layer of thin-walled polyhedral cells with a thin cuticle. Parenchyma cells have a large quantity of tannin-containing idioblasts located inside a procambial ring. The one-layered inner epidermis consists of flattened cells. In fruits the one-layered exocarp is covered by a thick cuticle. The mesocarp consists of three distinct regions, the middle region being a sclerenchymatous layer. The one-layered endo-carp shows cells with little cohesion. The occurrence of canals consisting of a net of resinous cells was also observed in the mesocarp. Secretion was of an elaborate composition. Differentiation of the secretory structures begin in the floral bud ovary, where they appear as idioblasts containing tannin. The taxonomic position of this tribe, as well as the function of the mesocarp secreting canals, are discussed.     

Pericarp histogenesis and histochemistry during fruit development in Butia capitata (Arecaceae)

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.

     

Specific Changes of Exocarp and Mesocarp Occurring during Softening Differently Affect Firmness in Melting (MF) and Non Melting Flesh (NMF) Fruits

Melting (MF) and non melting flesh (NMF) peaches differ in their final texture and firmness. Their specific characteristics are achieved by softening process and directly dictate fruit shelf life and quality. Softening is influenced by various mechanisms including cell wall reorganization and water loss. In this work, the biomechanical properties of MF Spring Crest’s and NMF Oro A’s exocarp and mesocarp along with the amount and localization of hydroxycinnamic acids and flavonoids were investigated during fruit ripening and post-harvest. The objective was to better understand the role played by water loss and cell wall reorganization in peach softening. Results showed that in ripe Spring Crest, where both cell turgor loss and cell wall dismantling occurred, mesocarp had a little role in the fruit reaction to compression and probe penetration response was almost exclusively ascribed to the epidermis which functioned as a mechanical support to the pulp. In ripe Oro A’s fruit, where cell wall disassembly did not occur and the loss of cell turgor was observed only in mesocarp, the contribution of exocarp to fruit firmness was consistent but relatively lower than that of mesocarp, suggesting that in addition to cell turgor, the integrity of cell wall played a key role in maintaining NMF fruit firmness. The analysis of phenols suggested that permeability and firmness of epidermis were associated with the presence of flavonoids and hydroxycinnamic acids.     

核桃果皮的发育解剖学研究

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,     

山茱萸核果的解剖结构和组织化学定位

用解剖学和组织化学的方法研究了山茱萸 (MacrocarpiumofficinacleSieb .etZucc .)核果的解剖结构和皂甙、多糖的组织化学定位。结果表明 :山茱萸核果的外果皮革质 ,由一层被覆较厚角质膜的表皮细胞构成 ;中果皮肉质 ,由多列薄壁细胞构成 ,含色素细胞不均匀分布 ,靠近外果皮的薄壁细胞大多为含色素细胞 ,使果实呈现红色 ,向内的薄壁细胞体积渐渐增大 ,在较大的薄壁细胞以及维管束周围的薄壁细胞内常含有色素块。组织化学定位显示 :外中果皮的含色素细胞的色素块中含有丰富的皂甙和多糖 ,果实的中果皮的薄壁细胞在未成熟时就已经形成皂甙 ,并随着果实的成熟逐渐增加积累     

油茶叶肿病子房瘿体和叶片瘿体的形态结构特征观察

采用光学显微镜观察了油茶叶肿病子房瘿体和叶片瘿体的形态特征和组织结构特点。结果表明:(1)油茶叶肿病瘿体是油茶的幼嫩子房和幼叶被细丽外担菌感染后所导致的组织增生而成的,细丽外担菌分布于成熟子房瘿体的外表面和叶片瘿体的表面。(2)子房瘿体由受感染的雌蕊子房增殖而来,成熟后表皮层脱落。(3)子房壁分两层,外层子房壁肉质肥厚,主要由大型薄壁细胞构成,是食用的主要部分,内层子房壁为较薄的心皮层,内外两层子房壁之间具有较大的空隙;心皮内有胚珠,胚珠着生在中轴胎座上,胚珠内部中空而没有育性。(4)叶片瘿体为受感染的幼嫩叶片增殖所致,由大型薄壁细胞构成,瘿体表面具表皮层,成熟后表皮脱落。(5)在正常叶片与叶片瘿体的过渡区内有维管束相通,瘿体侧的厚度比正常叶片厚度增加3～4倍,细胞体积增大5～10倍,但瘿体细胞内无叶绿体。     

Development and structure of the pericarp and seed of Rhus lancea L. fil. (Anacardiaceae), with taxonomic notes

The pedicel of the female flower of Rhus lancea is distinctly articulated and usually carries three bracteoles. In the linear tetrad the micropylar megaspore forms the 8-nucleate embryo sac of the Oenothera -type. The single, bitegmic ovule is anatropous. The ripe, loose, papery exocarp consists mainly of the outer epidermis and a sclerified hypodermis. The mesocarp is not a typical sarcocarp, since the ridges and the inner layers are sclerenchymatous. The endocarp, originating from the inner epidermis, consists of four layers and its structure and microchemistry emphasize the close alliance of Rhus with other genera of the section Rhoideae. The endotestal seed indicates a phylogenetic affinity between the Anacardiaceae and the Burseraceae.     

兰花蕉种子的解剖学和组织化学研究

兰花蕉种子球形或近球形,具表皮毛,种脊不明显。种子包括假种皮、种皮、外胚乳、内胚乳和胚五部分。假种皮具３～４条粗毛状裂片,包围种子或不定向伸展;裂片最外方为１层表皮细胞和１～３层厚壁细胞,内方为薄壁细胞;表皮细胞和厚壁细胞的壁增厚并木质化;成熟时裂片下部１／２段中空。种皮由外珠被发育而来,但内珠被在种子发育后期才萎缩。种皮分化为外种皮,中种皮与内种皮;外种皮由１层表皮细胞构成,其细胞壁增厚并木质化;中种皮外方为２～３层厚壁细胞,内方由１２～１５层薄壁细胞构成;内种皮由１层径向延长的石细胞构成,其细胞壁网状增厚,胞腔不明显。外胚乳极不显眼,大部分只由１层切向延长的长方形细胞构成,局部为２～１７层细胞;外胚乳细胞主要含许多脂类物质及少量蛋白质颗粒,不含淀粉。内胚乳占据种子很大的体积,由通常径向延长的长方形、长条形或方形薄壁细胞构成;细胞内充满淀粉粒和通常一颗亦有２至多颗菱形或方形蛋白质晶体,脂类物质极少。胚圆柱形,胚根和胚芽不明显。种子珠孔区不分化出珠孔领和孔盖,但具柄,柄的远轴端边缘大部分着生假种皮,着生假种皮一侧柄略膨大。合点区内种皮出现极宽的缺口,缺口间为整体呈弧状长条形的合点区厚壁细胞群。较粗的种脊维管?     

龙眼果皮形态结构比较观察及其与果实耐贮运的关系

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。     

山茱萸果皮的解剖学研究

本文报导了山茱萸果皮的解剖学研究结果.外果皮由一层表皮细胞构成.中果皮外方为3-4(5)层厚角组织细胞,这些细胞通常含有单宁;其内方包含薄壁细胞、单宁细胞和8束维管束.单宁细胞成团或零星分布于薄璧细胞中,前者的体积明显大于后者.单宁细胞的单宁与多糖结合在一起.维管束含有环纹、螺纹、梯纹、网纹及孔纹管胞,还有少数散生的纤维.内果皮高度木质化,主要由多种形状的石细胞组成,其间分布了肉眼可见、排列成环状的异细胞,偶见少数生活石细胞及薄壁细胞.内果皮有3束维管束.     

Pericarp anatomy of wild roses (Rosa L., Rosaceae)

The pericarp anatomy of representatives of all subgenera and sections of the genus Rosa was studied. All species have the same basic pericarp structure: it is composed of inner and outer endocarps, mesocarp and exocarp formed by the epidermis and hypodermis. The differences concern mainly the thickness of particular layers, and the shape and size of their cells. Cells of the endocarp and mesocarp are thick-walled. The only exception is Rosa rugosa mesocarp, which is composed of rather thin-walled cells with a large lumen. The endocarp structure of Rosa achenes resembles the drupe of the genus Prunus s.l. and drupelets of Rubus species.