DEVELOPMENT OF THE SEED AND FRUIT IN MELAMPYRUM NEMOROSUM L. AND M. ARVENSE L.

1965 ◽  
Vol 43 (12) ◽  
pp. 1511-1521 ◽  
Author(s):  
B. Tiagi
Keyword(s):  
Seed Coat ◽  
Embryo Sac ◽  
Developing Seed ◽  
Chalazal Haustorium ◽  
Meristematic Region ◽  
Micropylar Canal ◽  
Pass Through

The ovary is bilocular, with four massive axile placentae, each bearing a sessile hemianatropous, unitegmic, and tenuinucellate ovule. The innermost integumentary layer forms endothelium around the micropylar part of the embryo sac. The micropylar canal is surrounded by the micropylar tube, whereas the endothelium is hypodermal in this region. The endothelium and an adjacent meristematic region contribute to the growth of the integument. The endosperm is of the Brunella type described by K. Schnarf in 1929. The chalazal haustorium is a highly aggressive, two-nucleate chamber which becomes inactive and is filled with a haustorial chalazal endosperm. The two multinucleate micropylar haustorial cells give rise to many tubular extensions which pass through the micropylar tube, but only one reaches the placenta. The cells of the storage endosperm are pitted and thickened with hemicellulose. An opaque tanniferous zone of endosperm separates the storage endosperm from the chalazal endosperm. The embryo is small and straight, with two cotyledons and a hypocotyledonary region. The seed coat is feeble, one to three layered. The pericarp is many layered and cuticularized. The two innermost lignified layers form columns at the dorsal line of the two valves of the capsule, where it dehisces. The chalazal part of the developing seed absorbs nourishment directly from the pericarp.

scholarly journals Anatomy of the pericarp and seed-coat of Lithraea molleoides (Vell.) Engl. (Anacardiaceae) with taxonomic notes

2005 ◽  
Vol 48 (4) ◽  
pp. 599-610 ◽  
Author(s):  
Sandra Maria Carmello-Guerreiro ◽  
Adelita Aparecida Sartori Paoli
Keyword(s):  
Calcium Oxalate ◽  
Seed Coat ◽  
Outer Layer ◽  
Cell Walls ◽  
Embryo Sac ◽  
Vascular Bundles ◽  
Developing Seed ◽  
Secretory Canals ◽  
Polyhedral Cells ◽  
Parenchymal Cells

The aim of the present work was to record anatomical data for the fruit and seed of Lithraea molleoides (Vell.) Engl, and compare the results with those for L. brasiliensis and the genera Schinus and Rhus. The L. molleoides fruit was a drupe with a friable and lignified exocarp. The mesocarp was parenchymatous with large secretory canals associated with vascular bundles. The endocarp consisted of four layers: an outer layer of polyhedral cells with prismatic crystals of calcium oxalate, and three inner layers of sclereids in a palisade arrangement. The ovule was anatropous, unitegmic, and crassinucelate. In the chalazal region, a cup-like zone of tanniniferous parenchymal cells formed the hypostase. The developing seed had a circinotropous-like shape, that originated through curvature of the long, coarse funicle that surrounded the tegument and embryo sac. The ripe seed was endotestal with bar-like thickenings or pittings in the cell walls.

EMBRYOLOGICAL STUDIES IN CANADIAN REPRESENTATIVES OF THE TRIBE RHINANTHEAE, SCROPHULARIACEAE

1963 ◽  
Vol 41 (2) ◽  
pp. 267-302 ◽  
Author(s):  
Govindappa D. Arekal
Keyword(s):  
Ab Initio ◽  
Embryo Development ◽  
Seed Coat ◽  
Nuclear Division ◽  
Vertical Wall ◽  
Embryo Sac ◽  
Intercellular Spaces ◽  
Chalazal Haustorium ◽  
Thin Walled ◽  
Polygonum Persicaria

Descriptions are given of the ovary and ovules, megasporogenesis, embryo sac, endosperm, embryo, and seed coat structure of Euphrasia arctica Lange, Orthocarpus luteus Nutt., and Melampyrum lineare Desr. Although the ovary is usually bicarpellary, syncarpous, and bilocular with axile placentation in the tribe, a tendency toward unilocularity and parietal placentation occurs in Orthocarpus luteus. The number of ovules is reduced to four in Melampyrum lineare. Development of the embryo sac is of the monosporic eight-nucleate type in Euphrasia arctica and Orthocarpus luteus, but is tetrasporic and seven-nucleate in Melampyrum lineare. No fusion of polar nuclei occurs in the latter. The endosperm is ab initio cellular. Nuclear division in the primary micropylar chamber is followed by a vertical wall which remains incomplete. Aggressive haustoria develop at opposite ends of the endosperm. The chalazal haustorium is unicellular and binucleate. The micropylar haustorium is incompletely bicelled, with four nuclei in E. arctica and M. lineare and two nuclei in O. luteus. In M. lineare six to eight tube-like processes develop from the micropylar haustorium of which one usually enlarges and enters the funicle. The endosperm proper is generally uniform in E. arctica and O. luteus, but in M. lineare it becomes differentiated into three regions, the massive micropylar part consisting of cells with thickened, prominently pitted walls and the chalazal part of thin-walled cells with large intercellular spaces. Embryo development in E. arctica and O. luteus resembles that of Capsella bursa-pastoris, while development in M. lineare follows that of Polygonum persicaria. Embryologically Melampyrum lineare differs markedly from other members of the tribe.

Fruit and Seed Structure of Thryptomene calycina (Myrtaceae)

1993 ◽  
Vol 41 (2) ◽  
pp. 183 ◽  
Author(s):  
DV Beardsell ◽  
RB Knox ◽  
EG Williams
Keyword(s):  
Seed Coat ◽  
Embryo Sac ◽  
Small Cells ◽  
Seed Structure ◽  
Polygonum Type ◽  
Developing Seed ◽  
Nucellar Tissue ◽  
Auramine O ◽  
Hydrophobic Lipid ◽  
Thin Band

At anthesis the receptacle of flowers of T. calycina (Lindl.) Stapf is enclosed by a layer of small cells with a thick cuticle. The hypodermis consists mostly of large oil-containing cells interspersed with much smaller cells. The tissue surrounding the ovary consists mostly of spongy parenchyma. The micropyle of the ovule is formed only by the inner integument which is double-layered. The embryo sac at anthesis is typical of the Myrtaceae, and appears to follow the monosporic polygonum type, with considerable nucellar tissue surrounding it. In a mature fruit the parenchyma is compressed into a thin band surrounding the seed. The integuments form a two-layered seed coat within the fruit. The aborted ovule is displaced below and to one side of the developing seed. In fruit weathered for several years there is an accumulation of phenolic material giving the fruit a black appearance. The two layers of the seed coat within freshly shed fruit lie closely together and stain strongly with the lipid stain auramine O. In fruit weathered for at least 2 years the two layers of the seed coat become separated for at least part of their length and staining from auramine O is less intense. The breakdown in seed dormancy in weathered fruits is probably due to a less complete barrier to water uptake provided by the separation of the two layers. This would increase lateral and radial movement of water. The observed reduction in the hydrophobic lipid content of the testa layers probably also aids water entry into the seed in a weathered fruit.

Ovule and seed structure in Scolopia zeyheri (Scolopieae), with notes on the embryology of Salicaceae

Bothalia ◽  
2005 ◽  
Vol 35 (2) ◽  
pp. 175-183 ◽  
Author(s):  
E. M. A. Steyn ◽  
A. E. Van Wyk ◽  
G. F. Smith
Keyword(s):  
Microscopic Study ◽  
Seed Coat ◽  
Embryo Sac ◽  
Single Layer ◽  
Relevant Information ◽  
Seed Structure ◽  
Globular Embryo ◽  
Polygonum Type ◽  
Old World ◽  
Seed Characters

Scolopia zeyheri (Nees) Harv. is a widespread African tree and a member of the largest genus of the tropical Old World tribe Scolopieae (Salicaceae sensu lato). This light microscopic study is the first report on ovule and seed structure in the genus and the tribe. Ovules vary from four to six per ovary, are anatropous. crassinucellate. bitegmic and occur in an epitropous (rarely pleurotropous). median-parietal position in the unilocular, usually bicarpellate ovary. A very extensive nucellus cap. comprising nucellus epidermal derivatives and parietal tissue, characterizes the young ovule during mega- sporogenesis and megagametogenesis, but the chalazal nucellus is poorly developed. During meiosis. the micropvlar dyad cell degenerates early. The functional dyad cell forms two megaspores of which the chalazal one usually develops into a Polygonum-type embryo sac. At maturity, the micropylar end of the embryo sac is covered by the remnants of the nucellus epidermis, the parietal tissue having degenerated. The globular embryo has a short suspensor and lies in nuclear endosperm becoming cellular. The seed coat develops from both integuments, is tannimferous. has a glabrous surface with stomata and a single layer of exotegmic, longitudinal fibres.Results are compared with relevant information previously reported for genera in the tribes Flacourtieae. Samvdeae. Saliceae, Scyphostegiae and for Oncoha Forssk. (Salicaceae sensu lato). Embryologically Scolopia shows a number of ple- siomorphic features compared to other Salicaceae. For example, it lacks an extranucellar embryo sac. an apomorphic fea­ture in many Salicaceae. A summary of ovule and seed characters in Salicaceae sensu lato is given and contrasted with data available for Achariaceae  sensu lato. Embryological data broadly supports the reclassification of genera, traditionally referred to Flacourtiaceae. amongst Salicaceae sensu lato and Achariaceae sensu lato.

THE DEVELOPMENT OF THE BLUEBERRY SEED

1957 ◽  
Vol 35 (2) ◽  
pp. 139-153 ◽  
Author(s):  
Hugh P. Bell
Keyword(s):  
Seed Development ◽  
Seed Coat ◽  
Embryo Sac ◽  
Pollen Tubes ◽  
Homogeneous Plasma ◽  
Stage Of Development ◽  
Micropylar Endosperm ◽  
Mature Seeds ◽  
Number Of Seeds

Seed development was followed from fertilization to maturity. Pollen tubes required about 4 days to grow from stigma to ovule. In some plants, particularly bagged ones, nucellar cells remained alive and contents of the embryo sac degenerated. Many ovules did not develop. Seeds were counted and sorted in a random representative collection of 1075 berries. The average number of seeds per berry was 64.2. Of these 49.9 (or 77.7%) were imperfect. More complete pollination increased the percentage of normally developing ovules. Development of perfect seeds followed a familiar pattern. Unfamiliar features were noted as follows: 1. Degeneration of cells at both micropylar and chalazal ends resulted in a homogeneous plasma. This plasma formed strands across haustoria and almost completely surrounded the zygote. 2. Micropylar endosperm cells formed a dense plug. Developing embryos may have had difficulty in penetrating this plug. 3. Many embryos had died at some stage of development. 4. A conspicuous integumentary tapetum was present until the endosperm was about half its final size.Embryo development was the "soland" type. Mature seeds were "axile linear". Imperfect seeds were chiefly of two types: (a) medium sized and solid with middle integumentary layers lignified, or (b) small and collapsed with all tissues inside seed coat disintegrated. No imperfect seed had an embryo.

scholarly journals Embriología de Erythroxylum havanense Jacq. (Erythroxylaceae)

2017 ◽  
pp. 25
Author(s):  
Sonia Vázquez-Santana ◽  
César A. Domínguez ◽  
Judith Márquez-Guzmán
Keyword(s):  
Seed Coat ◽  
Embryo Sac ◽  
Pollen Grains ◽  
Endosperm Development ◽  
Anther Wall ◽  
Starch Grains ◽  
Reproductive Structures ◽  
Exine Sculpturing ◽  
Erythroxylum Havanense ◽  
Mature Anther

We studied the development of reproductive structures in pin and thrum morphs of Erythroxylum havanense. The young anther wall consists of an epidermis, endothecium , 1-3 middle layers anda binucleate secretory tapetum. The mature anther wall has only two layers: epidermis and endothecium. Microspore tetrads are tetrahedral or isobilateral. Mature pollen grains are tricolporate, bicellular and contain starch grains. Exine sculpturing is verrugate in thrum pollen and reticulate in pin pollen. The ovule is sessile, pendulous, anatropous, bitegmic and crassinucellate. The embryo sac is heptacellular. An endothelium is differentiated. The endosperm development is nuclear, and the basal part of the nucellus persists during early endosperm development. Both integuments form the seed coat.

UJI VIABILITAS TERHADAP BENIH POLYEMBRIONI

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Jasmi Jasmi
Keyword(s):  
Seed Germination ◽  
Seed Coat ◽  
Seed Viability ◽  
Embryo Sac ◽  
Dry Weight ◽  
Food Storage ◽  
Number Of Leaves ◽  
Citrus Seed ◽  
Food Reserves ◽  
Germination And Growth

Seeds are mature ovules. One or more of the ovaries formed in the legume, but never more than one seed formed in the ovaries of monocots. Each ripe seed always consists of at least two parts, namely: (1) Embryo, (2) Seed coat (Seed coat or testa). Embryo is formed or derived from fertilized eggs (zygote) by undergoing cell division in the embryo sac. Seed coat is formed from the integument (one or more) of the ovules. In legumes generally there are two layers of seed coat. Every very young and growing seed always consists of three parts: (1) Embryo, (2) seed coat, (3) Endosperm. Endosperm is a storage food storage network which is absorbed by the embryo before or during seed germination and is always present in very young seeds. Polyembryonics is the presence of more than one embryo in one seed, but these embryos do not always mature or mature, remain undeveloped or degenerate. The purpose of this research is to study the germination of one seed that has more than one embryo and to determine the growth of seedlings from polyembryonic seeds. The results showed that the highest plant growth (plant height, number of leaves, fresh weight and dry weight of orange seeds) was found in orange seeds that had 1 embryo compared to orange seeds which had 2 and 3 embryos. Seed germination and growth is strongly influenced by the amount of food reserves stored in seeds (Magagula and Ossom 2011 in Hasnah M, 2013). Keywords: Citrus Seed, Polyembrioni, Seed Viability

scholarly journals Construction of the Seed-Coat cDNA Microarray and Screening of Differentially Expressed Genes in Barley

2004 ◽  
Vol 36 (10) ◽  
pp. 695-700 ◽  
Author(s):  
Jin-Song Pang ◽  
Meng-Yuan He ◽  
Bao Liu
Keyword(s):  
Cdna Microarray ◽  
Seed Coat ◽  
Solid Material ◽  
Cdna Clones ◽  
Dna Fragments ◽  
Wild Type ◽  
Expression Ratio ◽  
Over Expression ◽  
Developing Seed ◽  
Material Basis

Abstract Some barley mutants can synthesize neither anthocyanins nor proanthocyanidins in the seed coat, which is related to several genes in locus Ant13, but the exact model of action remains unknown. We used the cDNA microarray technology with barley transcription-deficient mutant (ant13-152) that does not synthesize proanthocyanidins as the tester, and its wild type genotype (Triumph) as the driver, to study this question. Six-thousand and forty-eight clones from the wild type Morex testa+pericarp cDNA library were amplified using PCR, and the DNA fragments were spotted on commercial amino-modified glass slide as microarray. The mRNAs from the developing seed coat (8–15 days) of both the mutant and the wild-type barley plants were isolated, and labeled respectively with Cy3-dUTP and Cy5-dUTP when reversely transcribed to cDNAs. The labeled cDNAs were used as probes, mixed at the same molar concentration, and hybridized with the DNA fragments on the slide. Seventy clones exhibiting marked differential expression (ratio>4) were identified from the microarray. All the 25 cDNA clones that showed an over-expression in wild type in comparison to the mutant ant13-152 were sequenced. It was found that most of these overexpressing clones were transcription/translation and hordein-associated genes. These results have laid a solid material basis for further elucidation of the metabolic pathway in proanthocyanidin synthesis in barley and likely other plants.

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