Academic literature on the topic 'Hypogeal germination'

AbstractConvallariamajalishas double dormancy and hypogeal germination, but no information is available on embryo growth or on the effects of light and gibberellic acid (GA3) on germination in this genus. Therefore, we investigated embryo growth and other germination features in seeds ofC. keiskeiand compared the data with those ofTrillium camschatcensein another study. Until now, in seeds with double dormancy, embryo growth and germination (epigeal) have been studied in detail only for seeds ofT. camschatcense. Phenology of embryo growth and emergence of cotyledonary petiole/root (hereafter root) and shoot in seeds ofC. keiskeiwere monitored outdoors. Effects of temperature, light and GA3on embryo growth and root and shoot emergence were tested under laboratory conditions. Roots emerged the first spring following seed dispersal in autumn. The embryo grew soon after root emergence, and germination was hypogeal. Seeds with an emerged root formed buds from which a shoot (leaf) emerged above ground during the second spring. Alternating temperatures and light had negative effects on root emergence, and GA3did not substitute for cold stratification in root emergence. Seeds ofC. keiskeihave double dormancy, but it differs from that inT. camschatcense. Based on differences in embryo growth before (T. camschatcense) versus after (C. keiskei) root emergence, and on epigeal (T. camschatcense) versus hypogeal (C. keiskei) germination, we suggest that two types of deep simple double morphophysiological dormancy (MPD) be recognized. Since embryo growth inC. keiskeidoes not fit the standard definition of MPD, we propose to expand this definition.

Seedling morphology was studied in Campa guianensisAubl. and Carapa proceraD. C. from germination to 90 days age. In both species germination is hypogeal and cryptocotylar. Both have rare albino seedlings. Though both species have compound leaves when adult, C, proceraputs out an average total of six simple leaves at germination, while leaves of C. guianensisare compound at all stages. This is the best diagnostic character for separation of the two species at the young seedling stage. Not diagnostic, but none the less useful, is the fact, that polyembryonic seeds are often found in C. procera,but not observed in C guianensis.

A technological approach to the morphofunctional classification of forest species seedlings defines the essential structures in the evaluation of germination testing and identifies changes in this structures that suggest abnormalities. The objective was to associate morphofunctional seedling classification to seed germination testing using official germination methods for 50 forest species from Amazon, Caatinga, Cerrado, Atlantic Forest and Pantanal biomes. Morphofunctional classification and abnormalities were defined using seedlings from 232 germination pre-tests and 1,160 samples that were formed for each species using seeds from distinct locations and with at least three levels of vigor. The phanero-epigeal germination with a non-developed epicotyl predominated among species (84%). Common in hypogeal germination, the development of the epicotyl occurred only in seedlings of Anadenanthera colubrina and Erythrina speciosa, both with epigeal germination. The need to supply and sustain the great mass produced in its long life cycle, the presence of the primary root was considered essential for the normal seedling classification of these forest species. Curled, stunted, necrotic, bifurcated primary root and those retained in the seed coat or in the fruit structures, were the main abnormalities of the seedling root systems. Damages to the shoot system were uncommon.

The aim of this work was to describe the morphology of seedlings and saplings of Pachyrhizus ahipa, a cultivated species of Phaseoleae (Fabaceae), analysing the seedling type and characterizing the structure of cotyledons, eophylls and metaphylls. It was observed that the seedling was semi-hypogeal, a germination type not yet recorded for the Phaseoleae tribe. It formed two opposite and unifoliated eophylls with an evident pair of stipels. Metaphylls were trifoliolate and had alternate phyllotaxis. Both eophylls and metaphylls were pinnate, camptodromous, and brochidodromous.

Studies were undertaken to determine effects of scarification, temperature, stratification, pH, and osmotic potential on seed germination; to determine the effect of planting depth on emergence; to describe the emergence sequence; and to quantify seedling development of bigroot morningglory. Mechanical and chemical scarification caused increased germination but cool, moist stratification did not break dormancy. Optimum germination occurred at 20 and 25 C and with alternating temperatures of 20/10 and 30/20 C. The optimum pH range for germination was between 6 and 8.5. Increasing the solution osmotic potential decreased germination linearly from 90% at −0.08 MPa to 0% at −0.8 MPa. Plant establishment was best at 2 to 4 cm and decreased at greater seeding depths. Seedling emergence was observed and recorded and found not to fit the classical models of hypogeal or epigeal emergence. Only 3% of 5-day-old seedlings sprouted after being clipped to the root crown. When seedlings were 11 days old at clipping, over 85% of the plants sprouted. These results indicate that bigroot morningglory has the potential to successfully reproduce by seed and that the rapid development of the plant should be considered when designing control programs.

The taxonomic position of Backhousia anisata is reassessed on morphological and anatomical grounds and its affinities found to lie with the Acmena alliance. Backhousia anisata is glabrous and has a suite of wood anatomical character-states that are more consistent with a phylogenetic position in or near the Acmena alliance than with other Backhousia species; molecular data also support this placement. Since this species lacks the fleshy fruit, thick cotyledons and hypogeal germination characteristic of other members of the Acmena alliance, a new genus Anetholea Peter G.Wilson is described to accommodate it, and the new combination Anetholea anisata (Vickery) Peter G.Wilson made.

Areca palm is an ornamental palm largely used in landscape which propagate occur by seeds germination. However, the biometry and the endogenous and exogenous factors than can limit propagation of this plant are poorly known, so this work was aimed characterize biometrics of fruits and seeds of areca palm and evaluate the germination of seeds in different substrates. For this, the biometric analyses of length, diameter and weight were recorded; the description of internal and external morphology of frit and seed were also studded. The treatments to improvement of seed germination were intact seeds (T1), intact seeds soaked in 500 mg L-1 GA3 solution (T2), physically scarified seeds with the aid of sandpaper (T3) and physically scarified seeds after immersion in 500 mg L-1 GA3 solution (T4). The Seeds were sown in containers containing sand, coir dust or vermiculite. The areca pal fruits and seeds are both, elliptical shape and the weight of fruits and seeds is 1.70g and 1.04g, respectively. There is positive correlation between fruit weight and length and diameter of the fruit and just like the diameter has a positive correlation with the diameter of the seed. The mechanical scarification improve the seed germination. The Coir dust is the most atrophied substrate to seed germination of areca palm. The seed germination of Areca palm is hypogeal and the protrusion of the haustorium was observed at 59 days after sowing and the plantlets is fully grown at 153 after sowing.

The interest in Syagrus schizophylla as an ornamental palm tree and the demand for conservation and preservation of the species led to this research. The objective was to study the physiological characteristics of its germination at different temperatures, as well as the morphological and biometrical characterization of diaspores and seedlings at the initial stages of growth and development. The research was divided into two experiments. In the first one, the aim was to identify the water absorption phases of seeds during germination under five scarification treatments as follows: intact diaspores, scarified diaspores, diaspores with endocarp rupture and intact seeds. In the second experiment, germination was tested at 25, 30 e 25 - 35 ºC; the first germination count, seedling emergence, abnormal seedlings, non-germinated seeds, the emergence curve, the emergence speed index and the mean time of emergence were evaluated. Afterwards, the morphological and biometrical characteristics of diaspores and seedlings were described. The water absorption curve observed under the different scarification treatments showed different water absorption patterns. Emergence percentages were 53, 61 and 47% at 25, 30 and 25 - 35 ºC, respectively. The highest emergence speed index was obtained at 30 ºC. The mean time of emergence was 30 days, approximately, under all the temperatures tested. The diaspores showed a great variability in both shape and size, presenting a globular to ovoid shape with an average length of 2.44 cm and an average width of 1.39 cm. The germination can be classified as hypogeal crypto cotyledonal of the remote-tubular type.

Aiming to compare morphofunctional features related to dispersion and establishment of plants, this study evaluated seed biometry and biomass, as well as germination and emergence potential in eight plant species native to the Semideciduous Seasonal Forest. Biometric measurements and biomass of seeds were obtained with a caliper and a precision scale. Afterwards, they were subjected to a germination test in BOD chambers under constant temperature and 12 hours photoperiod, and sown in styrofoam trays containing organic substrate and sand, kept in full sunlight. Data from germination and emergence was subjected to cluster analysis, according to the functional morphotype of the seedling. Most species presented seeds with a rounded shape, uniform staining at the mature stage, varied coat consistency, two types of dispersal syndromes (anemochory and zoochory) and four morphofunctional patterns in developing seedlings (crypto-hypogeal-storers, crypto-epigeal-storers, phanero-epigeal-storers and phanero-epigeal-foliaceous). The species belonging to group I (Albizia niopoides, Cedrela fissilis, Pterogyne nitens and Randia ferox) have foliaceous photosynthetic cotyledons and group II (Cabralea canjerana, Eugenia pyriformis, Inga laurina and Poecilanthe parviflora) have a reserve cotyledon. Species of group I had higher means in the percentage and rate of germination, less variability and amplitude of days for seedlings emergence. On the other hand, species of group II showed higher mean values in seed biometry and biomass. Thus, seeds with foliaceous cotyledons have an optimized development because of luminosity, whereas seeds with reserve tend to have slower development, remaining at the seedling stage for a longer time.

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Data of morphometric of fruits and seeds, although they still are scarce, are important for studying genetic improvement of populations, as well for improvement of storage conditions and for improvement of seedling yield. In order to subsidizing the knowledge of Jacaranda decurrens ssp. symmetrifoliolata (carobinha), this research had as aims to evaluate morphometric of fruits, seeds and seedlings and germinative potential of seeds that were stored in different periods, at environmental temperature. Morphometrical study of fruits and seeds was done in February, 2007, at UFGD, in Dourados, MS. In a sample of 116 fruits that were gathered in aleatory way from a populations of 25 plants, mass, length, width and thickness, besides the counting of seeds per fruit, were determined. In biometrical analysis of seeds, a sample with 550 seeds which was gathered in aleatory way from fruits was used, and length, width and thickness were measured. Germination was studied after three periods of storage of seeds (120, 480 and 720 days) and in four temperatures of germination, which three of them were constant (18, 25 and 30ºC, under constant light) and one alternated (20-30ºC under light, with photoperiod of 12 hours day/night). Treatments were arranged in 3 x 4 factorial scheme on a complete randomized design with three replications. Seedling development was evaluated 35 days after sowing, in which measurement of length of root and stalk. Carobinha fruits showed great variability of mass, length, width, thickness and number of seeds, which averages were 45.5 g, 86.5 mm, 62.7 mm, 18.2 mm, respectively. Averages for length, width and thickness of seeds were 9.2mm, 8.8 mm and 1.5mm, respectively. Percentage of germination and velocity of germination of seeds that were stored under environmental temperature were influenced significantly by periods of storage, which the greatest averages were registered under temperature of 25ºC (69.4% and 0.983). Seeds that were stored for 480 and 720 days, under environmental temperature lost completely vigor. Carobinha seedlings showed hypogeal germination, conforming in crypto cotyledonal type. The development of root and stalk was higher at 25ºC, but eophyls of seedlings that were germinated under temperatures of 30ºC and alternated showed themselves more developed
Dados de morfometria de frutos e sementes, embora ainda sejam escassos, são valiosos em estudos de melhoramento genético de populações, bem como na melhoria das condições de armazenamento e para a otimização na produção de mudas. A fim de subsidiar o conhecimento da Jacaranda decurrens ssp. symmetrifoliolata (carobinha), este trabalho teve como objetivos avaliar a morfometria dos frutos, sementes e plântulas e o potencial germinativo das sementes armazenadas em diferentes períodos, à temperatura ambiente. O estudo morfométrico dos frutos e sementes foi realizado emfevereiro de 2007 na UFGD, em Dourados, MS. Em uma amostra de 116 frutos colhidos aleatoriamente de uma população de 25 plantas cultivadas ex situ, foi determinada a massa, o comprimento, a largura e a espessura, além da contagem de sementes por fruto. Na análise biométrica das sementes, foi utilizada uma amostra de 550 sementes, retiradas aleatoriamente dos frutos, sendo medidos comprimento, largura e espessura. A germinação foi estudada após três períodos de armazenamento das sementes (120, 480 e 720 dias) e em quatro temperaturas de germinação, sendo três constantes (18, 25 e 30ºC, sob luz constante) e uma alternada (20-30ºC sob luz, com fotoperíodo de 12 horas dia/noite). Os tratamentos foram arranjados em esquema fatorial 3 x 4, em delineamento inteiramente casualizado, com três repetições. O desenvolvimento das plântulas foi avaliado 35 dias após a semeadura, sendo realizadas medidas de comprimento de radícula e caulículo. Os frutos da carobinha apresentaram grande variabilidade de massa, comprimento, largura, espessura e número de sementes, sendo as medianas de 43,5 g, 86,5 mm, 62,7 mm, 18,2 mm, respectivamente. As medianas para comprimento, largura e espessura das sementes foram de 9,2 mm, 8,8 mm e 1,5 mm, respectivamente. A porcentagem de germinação e a velocidade de germinação das sementes armazenadas sob temperatura ambiente foram influenciadas significativamente pelos períodos de armazenamento, sendo as maiores médias registradas sob 25ºC (69,4% e 0,983, respectivamente). As sementes armazenadas por 480 dias e 720 dias sob temperatura ambiente perderam totalmente a capacidade de germinação. As plântulas de carobinha apresentaram germinação hipógea, enquadrandose no tipo criptocotiledonar. O desenvolvimento da radícula e caulículo foi maior a 25ºC, mas os eofilos das plântulas germinadas nas temperaturas de 30ºC e alternada apresentaram-se mais desenvolvidos.

Orientador: Edvaldo Aparecido Amaral da Silva
Banca: João Nakagawa
Banca: Daiani Ajala Luccas
Resumo: Sementes de alta qualidade fisiológica é pré-requisito para o estabelecimento da cultura e para a produção. A qualidade fisiológica das sementes é adquirida durante o desenvolvimento. O conhecimento sobre quando cada componente da qualidade fisiológica é adquirido durante a fase de maturação da semente permite um ajuste no momento ideal da colheita e consequentemente colheita no período em que a semente se encontra com o máximo de qualidade fisiológica. Portanto, o objetivo deste trabalho foi estudar a aquisição de germinação, tolerância à dessecação, vigor e longevidade durante a fase de desenvolvimento de duas cultivares de amendoim produzidas em duas safras agrícolas. A produção de sementes de duas cultivares, IAC OL3 e IAC 505 cultivada no ano de 2016/2017 e no ano de 2017/2018 seguida de coleta e caracterização morfológica das sementes nos estádios reprodutivos R5, R6, R7, R8 e R9. Para cada estádio foi determinado o teor de água, massa fresca, massa seca, germinação e o vigor das sementes. O vigor foi determinado pela seguintes avaliações: primeira contagem de germinação, T50, crescimento de raiz e parte aérea, massa de matéria seca de raiz e parte aérea e avaliação de protrusão. Em seguida, as sementes foram submetidas a secagem e foi realizada o teste de germinação para a determinação da aquisição de tolerância à dessecação. As sementes secas foram então armazenadas à 35°C e 75% de umidade relativa, para caracterizar a aquisição de longevidade. A germinação foi inicia... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Seeds of high physiological quality are pre-requisite for the establishment of the crop and for the production. The physiological quality of the seeds is acquired during development. Knowledge about when each component of physiological quality is acquird during the maturation phase of the seed allows an adjustment at the ideal time of harvest and consequently harvest in the period in which the seed meets the highest physiological quality. Therefore, the objective of this work was to characterize and understand the pattern of the acquisition of the components of physiological quality in peanut seeds (germination, desiccation tolerance, vigor and longevity). Seed production of two cultivars, IAC OL3 and IAC 505 was carried out in 2016/2017 and 2017/2018 followed by collection and morphological characterization of the seeds at the reproductive stages R5, R6, R7, R8 and R9. For each stage the water content, fresh weight, dry weight, germination and vigor on fresh seeds were determined. The vigor was determined by the following evaluations: first germination count, T50, root and shoot growth, root and shoot dry matter mass and protrusion evaluation. Then seeds were submitted to drying and carried out the germination test to determine the acquisition of desiccation tolerance. The dried seeds were then stored at 35°C and 75% relative humidity to characterize the acquisition of longevity. Germination was initiated at the R5 stage and reached its maximum at the R9 stage. The desiccati... (Complete abstract click electronic access below)
Mestre

Including peanut (Arachis hypogaea L.) in crop rotations is common for eastern Virginia and the Carolinas, as it thrives in the long growing season and sandy soils. Boron (B) is widely deficient, and is more prone to leeching in sandy soils. Applied B has difficulty reaching growing points as B has reduced phloem mobility in peanuts. Current B fertilization recommendations are based on only three studies from the early 70s. Many changes have been made in cultivar breeding since then. This research examines if recommended B application rates and times are still necessary for optimal yield, plant health and seed quality for current cultivars. Two experiments in seven fields compared four total amounts of B applied (0, 0.3, 0.6, and 1.1 kg ha-1), and application time (planting; beginning peg, R2; full seed, R6; planting and R2; planting and R6), and runner and Virginia market types, newer and obsolete cultivars, with or without B fertilization. Leaf B was elevated only directly after fertilization (p=0.004, p<0.001), and in relation to total B applied (p<0.001), but seed B content was unaffected. Yield was not impacted by B rate or application time. Yield was higher (p=0.012) for newer cultivars when B fertilized, but no different than obsolete cultivars with B. Seed from obsolete cultivars had higher (p=0.010) B, no difference between market types or B fertilization. Germination of all seed was 97%. Based on this research, it is not necessary to apply B for optimal yield, plant health and seed quality for current cultivars.
Master of Science in Life Sciences

The education of natural history at primary and seconadry school is nowadays focused on theoretical interpretation. The subject of this diploma thesis is to inform pupils about the stimulating and inhibiting substances´influence on seed germination and emergence. This diploma thesis needs practical approach to pupils during the project basing, documenting seed germination, growing and its evaluation. The aim of this diploma thesis is to practically show to pupils the problems of seed germination and emergence of commonly available seeds in the school environment.