Academic literature on the topic 'Endosperm morphology'

Programmed cell death (PCD) is a requisite, genetically controlled process in plants resulting in the death of particular cells and tissues and the recycling of the cellular constituents back to the organism. PCD in the lateral and micropylar endosperm cells during and following germination of tomato ( Solanum lycopersicum L.) seeds was characterized by transmission electron microscopy, by terminal d-UTP nick-end labelling of nuclei, and agarose gel electrophoretic analysis of genomic DNA. Postgerminative cells of lateral and micropylar endosperm displayed morphologies and terminal d-UTP nick-end labelling positive nuclei consistent with PCD. PCD was not detected in the lateral endosperm in the absence of the embryo. The embryo’s effect on promoting lateral endosperm PCD could be substituted with gibberellic acid at 50 μmol/L. Micropylar endosperm cells undergo PCD irrespective of incubation with or without the embryo; gibberellic acid only hastens the onset of PCD morphology. Precursor protease vesicles, novel endoplasmic reticulum derived organelles considered markers of PCD, were observed in postgerminative lateral and micropylar endosperm cells. Internucleosomal laddering was not detected in endospermic DNA. These results suggest that a late postimbibition gibberellic acid linked mechanism promotes PCD in the lateral endosperm, whereas the promotion of PCD in the micropylar endosperm occurs early in, or prior to, imbibition.

Australia's native grass species contain a diverse array of wild cereal relatives which are adapted to a broader range of environmental conditions than current commercial cereals and may contain novel alleles which have utility in commercial production systems. Characterizing the available variation in endosperm morphology is one of the first steps towardsin plantamanipulation of endosperm by either the introgression of novel alleles or bioengineering cereal starch and protein. The endosperm of 19 crop wild relatives (CWR) was examined using scanning electron microscopy (SEM). Mature caryopses were fixed, dehydrated, critical-point dried and then snap fractured transversely through the grain. Wild relatives exhibited similar types of starch granules to that of their respective cultivated species, though in general the wild species retained a greater proportion of the endosperm cell wall at maturity. The two species examined with no closely related cultivated species exhibited a rice-like endosperm. Wild sorghum relatives exhibited an abundance of endosperm variations described as variations in starch granule size, shape and surface morphology, and the distribution of protein bodies. This is particularly important because the grain ofSorghum bicolorhas inherently low starch and protein digestibility. These variations within the wild relatives of commercial cereals may provide novel sources of genetic diversity for future grain improvement programmes.

Acalypha gracilis, Euphorbia cotinifolia e Jatropha gossypiifolia pertencem a Euphorbiaceae e às respectivas subfamílias Acalyphoideae, Euphorbioideae e Crotonoideae. Informações sobre morfologia e desenvolvimento seminal de Euphorbiaceae são escassas na literatura. Este estudo tem por objetivo acompanhar o desenvolvimento morfoanatômico das espécies em questão. Os óvulos dessas espécies são anátropos, sésseis, crassinucelados e bitegumentados. A micrópila, em linha reta, é delimitada pelo endóstoma e exóstoma, é obliterada pela projeção do nucelo, não muito evidente em A. gracilis, que pode alcançar o obturador. As sementes são consideradas exotégmicas, albuminosas, com endosperma na maturidade contendo grãos de aleurona. O embrião apresenta eixo hipocótilo-radicular curto e cônico, cotilédones largos e foliáceos, sendo diferenciado tardiamente – primeiro ocorre todo o desenvolvimento do envoltório seminal, para que depois ele se desenvolva por completo. Jatropha gossypiifolia é endopaquicalazal e apresenta endosperma misto: núcleo-celular. Carúncula bem evidente ocorre em J. gossypiifolia, sendo que nas outras duas espécies é inconspícua.Palavras-chave: Anatomia; endosperma; morfologia; nucelo; tegumento. AbstractOntogenetic analyzes in seeds of Euphorbiaceae. Euphorbia cotinifolia and Jatropha gossypiifolia belong to Euphorbiaceae, and to the respective subfamilies Acalyphoideae, Euphorbioideae and Crotonoideae. Information on morphology and seminal development of Euphorbiaceae are lean in literature. This research aims to monitor the morphoanatomic development of the involved species. The ovule of these species are anatropous, sessile, bitegmic and crassinucelate. The micropyle, straight, is bounded by endostome and exostome, and obliterated by the projection of the nucellus, not very evident in A. gracilis. The seeds are considered exotégmic, albuminous endosperm at maturity containing aleurone grains. The embryo with hypocotyl-radicle axis is short, broad and foliaceous cotyledons, being distinguished later: first, all the seminal wrap development occurs, so that it evolves completely. J. gossypiifolia is endopachichalazal and presents mixed endosperm: cell nucleous. Caruncule is evident in J. gossypiifolia, but it is inconspicuous in the other two species.Keywords: Anatomy; endosperm; morphology; nucellus; integument.

Structural differences such as abnormalities, damage and free spaces in seeds may affect germination. The aim of this study was to study the relationship between eggplant seed morphology and seed germination. Ten seed lots of the eggplant cultivar Embu were evaluated by X-ray image analysis and the germination test. Seed image analysis was performed by Image Pro Plus® software and the whole seed area and free space between the embryo and endosperm were measured. The internal seed area filled by the embryo and endosperm was calculated from the difference between the whole seed and free space areas. Based on these results and visual seed analysis, seeds were classified into three categories and information on germination was obtained for each one. X-ray image analysis provides a perfect view of the internal seed parts and for seed morphology studies. An increase in seed area filled by the endosperm and embryo does not improve seed germination. Mechanical seed damage and deteriorated tissues can adversely affect seed germination.

Li, C.-Y., Li, W.-H., Lee, B., Laroche, A., Cao, L.-P. and Lu, Z.-X. 2011. Morphological characterization of triticale starch granules during endosperm development and seed germination. Can. J. Plant Sci. 91: 57–67. The morphology of starch granules and its changes during endosperm development and seed germination in triticale has been investigated under scanning electron microscopy (SEM). Starch granules were rapidly accumulating in triticale endosperm after 6 d postanthesis (DPA). The double-disk structure of starch granules was detected in endosperms from 6 DPA until 27 DPA in triticale and its parental crops, wheat and rye. The equatorial grooves of triticale starch granules were more susceptible to enzymatic hydrolysis than the broad or flat surfaces. Triticale starch was slowly degraded within 4 or 5 d post germination (DPG) and most starch granules were almost completely hydrolyzed after 9 DPG. Morphological changes of starch granules observed under SEM during the in vitro enzymatic hydrolysis were consistent with patterns identified during the germination process. As a hybrid of wheat and rye, triticale inherits many morphological characteristics of starch synthesis and storage in the seed endosperm. However, triticale also possesses unique features of granule shape, size, distribution, and enzyme susceptibility. These results will make it possible to effectively utilize triticale starch in the starch-based production.

Anatomy of normal and abortive fruit was compared at each of the three postpollination fruit drops characteristic of pecan [Carya illinoensis (Wangenh.) C. Koch]. Size differences between normal and abortive fruit decreased during the growing season, but differences in ovule size between normal and abortive fruit increased. During Drop II, normal and abortive fruit had an integument enclosing a massive nucellus in which an embryo sac was embedded, but embryo sac shape and constituents differed. Embryo sacs were distended in normal fruit and contained a definitive zygote as evidence of fertilization, i.e., union of egg and sperm. In contrast, embryo sacs in abortive fruit were shriveled and contained an egg apparatus as in unfertilized distillate flowers. During Drop III, normal and abortive fruit had a similar multicellular embryo. The nucellus in normal fruit was reduced to a cap at the micropyle region and cellular endosperm was evident. In contrast, the nucellus in abortive fruit was abundant and cellular endosperm was not evident. During Drop IV, embryo development in abortive fruit lagged behind that of normal fruit. Thus, we present the first direct evidence that aborted pecans deviate from normal fruit by an absence of a zygote at Drop II, a deficiency in cellular endosperm at Drop III, and a delay in embryo development at Drop IV.

The paper presents the results of the study on seed morphology and anatomy of Allium anisopodium Ldb. The seed shape is elliptic, glossy-black in color. The seed surface is scaly and its hilum appears in white color. The seed size is 1.7-2.1 mm long, 1.2-1.4 wide, 0.5-2.1 mm in thick and one thousand seed weight is 1.9 g. The anatomical structure is endospermic one cotyledons seed type. The seed coat thin and cotyledon is emphasized apparently from longitudinal section. The embryo is curved, coiled and black colored embryonic roots are relatively thick. The endosperm is surrounded by seed coat moreover between the cotyledon and embryo.

AbstractEarly maturity allows weedy rice (Oryza sativa L. f. spontanea) to persist by escaping harvest in paddy fields. A shorter grain-filling period contributes to the early maturity of weedy rice. However, the differences in morphology and endosperm development in the caryopsis between weedy and cultivated rice are largely unexplored. Here, we selected four biotypes of weedy rice and associated cultivated rice (ACR; Oryza sativa) from different latitudes to conduct a common garden experiment. The endosperm development process of the caryopsis was observed by optical microscopy and electron microscopy. Endosperm cell division and starch accumulation rate during grain filling were also measured. The grain development progress in weedy rice was more rapid and earlier than that in ACR. The endosperm development progress of weedy rice was 6 to 8 d earlier than that of ACR. The endosperm cells of weedy rice cellularized earlier and more rapidly than those of ACR, and the starch grains of weedy rice were more sharply polygonal and compactly arranged than those of ACR. The active endosperm cell division period in weedy rice was 4 to 7 d shorter than that in ACR, while the active starch accumulation period of weedy rice was 2 to 8 d shorter than that of ACR. The rapid development of endosperm cells and starch grains leads to the shorter grain-filling period of weedy rice. weedy rice.

Wild relatives of Oryza will be increasingly used in commercial rice breeding programs. However, the effects of rising atmospheric CO2 concentration on photosynthesis, light interception, canopy architecture and grain properties of the wild species are unknown. Two accessions of the Australian wild rice, O. meridionalis (Cape York and Howard Springs), were grown in ambient (aCO2, 400 ppm) and elevated CO2 (eCO2, 700 ppm) with O. sativa cv. Doongara in glasshouses and compared for photosynthesis, light interception, biomass and carbon (C) gain. For grain quality and endosperm morphology characterisation, an accession of O. australiensis was also studied. Photosynthesis (Amax) was enhanced at eCO2 by 20–50% across all genotypes, doubling the number of tillers, leaves and biomass. Light interception (¯STAR) was lower in eCO2 than in aCO2 due to denser canopies and less dispersed leaves. Nevertheless, plant biomass and C gain were higher in eCO2 than aCO2, despite less efficient light interception. Wild rices had denser crowns and lower light capture than domesticated rice in both CO2 treatments. Grain physicochemical analysis showed that seed length, seed width and 1000-seed weight were higher in eCO2 than in aCO2. Protein content decreased at eCO2 by 23% in Doongara and 15% in Howard Springs. Peak and final flour viscosity increased in the wild rices at eCO2, but in Doongara, only peak viscosity increased. SEM images showed that aleurone cell length and width were higher in Howard Springs, but the area and length of starch granules were larger in Cape York in eCO2 than in aCO2. Responses of rice endosperm morphology to eCO2 were dependent on genotype. In conclusion, Australian and Asian rice species have qualitatively distinct traits and responses to eCO2, as seen in light interception, photosynthesis, canopy architecture and grain properties.

Thesis (PhD (Food Sc))--Stellenbosch University, 2015.
ENGLISH ABSTRACT: Maize kernels consists of two types of endosperm, a harder vitreous endosperm and a softer floury endosperm, and the ratio of the vitreous and floury endosperm present mainly determines the hardness of the kernel. Maize (Zea mays L.) is a staple food in many countries, including South Africa, and is industrially processed into maize meal using dry-milling. For optimal yield and higher quality products, hard kernels are favoured by the milling industry. Despite many maize hardness methods available, a standardised method is still lacking, furthermore, no dedicated maize milling quality method exists. Using an industrial guideline (chop percentage), a sample set of different maize hybrids was ranked based on milling performance. Unsupervised inspection (using principal component analysis (PCA) and Spearman’s rank correlation coefficients) identified seven conventional methods (hectoliter mass (HLM), hundred kernel mass (HKM), protein content, particle size index (PSI c/f), percentage vitreous endosperm (%VE) as determined using near infrared (NIR) hyperspectral imaging (HSI) and NIR absorbance at 2230 nm (NIR @ 2230 nm)) as being important descriptors of maize milling quality. Additionally, Rapid Visco Analyser (RVA) viscograms were used for building prediction models, using locally weighted partial least squares (LW-PLS). Hardness properties were predicted in the same order or better than the laboratory error of the reference method, irrespective of RVA profile being used. Classification of hard and soft maize hybrids was achieved, based on density measurements as determined using an X-ray micro-computed tomography (µCT) density calibration constructed from polymers with known densities. Receiver operating classification (ROC) curve threshold values of 1.48 g.cm-3 , 1.67 g.cm-3 and 1.30 g.cm-3 were determined for the entire kernel (EKD), vitreous (VED) and floury endosperm densities (FED), respectively at a maximum of 100% sensitivity and specificity. Classification based on milling quality of maize hybrids, using X-ray µCT derived density and volume measurements obtained from low resolution (80 µm) µCT scans, were achieved with good classification accuracies. For EKD and vitreous-to-floury endosperm ratio (V:F) measurements, 93% and 92% accurate classifications were respectively obtained, using ROC curve. Furthermore, it was established that milling quality could not be described without the inclusion of density measurements (using PCA and Spearman’s rank correlation coefficients). X-ray µCT derived density measurements (EKD) were used as reference values to build NIR spectroscopy prediction models. NIR spectra were acquired using a miniature NIR spectrophotometer, i.e. a microNIR with a wavelength range of 908 – 1680 nm. Prediction statistics for EKD for the larger sample set (where each kernel was scanned both germ-up and germ-down) was: R2 V = 0.60, RMSEP = 0.03 g.cm-3 , RPD = 1.67 and for the smaller sample set (where each kernel was scanned only germ-down): R2 V = 0.32, RMSEP = 0.03 g.cm-3 , RPD = 1.67. The results from the larger sample set indicated that reasonable predictions can be made at the fast NIR scan rate that would be suitable for breeders as a rough screening method.
AFRIKAANSE OPSOMMING: Mieliepitte bestaan uit twee tipes endosperm, ‘n harder glasagtige endosperm en ‘n sagter melerige endosperm, en die verhouding waarin die twee tipes endosperm aangetref word, bepaal hoofsaaklik die hardheid van die pit. Mielies (Zea mays L.) is ‘n stapelvoedsel in baie lande, insluitende Suid-Afrika, en word industrieël geprosesseer na mieliemeel deur van droë-vermaling gebruik te maak. Vir optimale produksie en beter kwaliteit produkte, word harde pitte deur die meule verkies. Ongeag die beskikbaarheid van verskeie mielie hardheid metodes, ontbreek ‘n gestandardiseerde metode nog, en verder bestaan ‘n metode om mielies se maalprestasie te bepaal ook nie. ‘n Monsterstel, bestaande uit verskillende mieliebasters, is op grond van maalprestasie ingedeel deur van ‘n industriële riglyn (chop persentasie) gebruik te maak. Inspeksie sonder toesig (deur gebruik te maak van hoofkomponentanalise (HKA) en Spearman’s rangkorrelasiekoëffisiënte) het sewe onkonvensionele metodes (hektoliter massa, honderd pit massa, protein inhoud, partikel grootte indeks, persentasie glasagtige endosperm soos bepaal deur gebruik te maak van naby-infrarooi (NIR) hiperspektrale beelding en NIR absorbansie by 2230 nm) identifiseer as belangrike beskrywers van maalprestasie. Daarbenewens, is Rapid Visco Analyser (RVA) viskogramme gebruik om voorspellingsmodelle te bou deur gebruik te maak van plaaslik geweegte gedeeltelike kleinstekwadrate (PG-GKK) wat hardheidseienskappe kon voorspel met laer, of in dieselfde orde, laboratorium foute van die verwysingsmetodes, ongeag die gebruik van verskillende RVA profiele. Klassifikasie tussen harde en sagte mieliebasters was moontlik, gebasseer op digtheidsmetings soos bepaal met ‘n X-staal mikro-berekende tomografie (µBT) digtheids kalibrasie gebou vanaf polimere met bekende digthede. Ontvanger bedryf kenmerkende (OBK) kurwe drempelwaardes van 1.48 g.cm-3 , 1.67 g.cm-3 en 1.30 g.cm-3 is bepaal vir hele pit, glasagtige en melerige endosperm digthede, onderskeidelik, teen ‘n maksimum van 100% sensitiwiteit en spesifisiteit. Klassifikasie van die mieliebasters, gebasseer op maalprestasie en deur gebruik te maak van X-straal µBT afgeleide digtheid en volume metings soos verkry teen lae resolusie (80 µm) skanderings, was moontlik met goeie klassifikasie akkuraatheid. Vir heel pit digtheid en glasagtigtot-melerige endosperm verhouding metings is 93% en 92% akkurate klassifikasies verkry wanneer OBK kurwes gebruik is. Verder is dit vasgestel (deur gebruik te maak van HKA en Spearman’s rangkorrelasiekoëffisiënte) dat digtheidsmetings ingesluit moet word vir ‘n volledige beskrywing van maalprestasie. X-straal µBT afgeleide digtheid metings is gebruik as verwysings waardes om NIR spektroskopie voorspellings modelle te bou. NIR spektra is verkry deur van ‘n miniatuur NIR spektrofotometer, naamlik ‘n microNIR, bebruik te maak vanaf 908 – 1680 nm. Voorspellings statestiek vir die groter monsterstel (waar elke pit beide kiem-bo en kiem-onder geskandeer is) was vir HPD: R2 V = 0.60, RMSEP = 0.03 g.cm-3 , RPD = 1.67 en vir die kleiner monsterstel (waar elke pit was slegs kiem-onder geskandeer is) vir HPD: R2 V = 0.32, RMSEP = 0.03 g.cm-3 , RPD = 1.67. Die resultate van die groter monsterstel het aangedui dat redelike voorspellings moontlik is, teen die vinnige NIR skaderings tempo wat as rowwe vertoningsmetode geskik sal wees vir telers.