Conservation of Fern Spores

Ballesteros, Daniel

doi:10.1007/978-1-4419-7162-3_12

Cited by 15 publications

(12 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Una condición similar se observó también en otros licopodios (Sersic, 1983;Lugardon, 1990;Rincón et al, 2009; Rincón et al en prep.) y coincidiría con su utilización como aporte energético hasta que las esporas germinan y se forman los gametófitos (Gullvag, 1969;Gemmrich, 1977;Randi & Felippe, 1988;Raghavan, 1989;Ballesteros & Walters, 2007;Rincón et al, 2009;Ballesteros 2011;Gabriel & Galán y Prada, 2011). estudiaron la ontogenia del esporodermo en L. clavatum y señalaron que la formación del exosporio externo (responsable de la macro-ornamentación de las esporas) se inicia inmediatamente después de terminar la meiosis, durante la etapa de tétrada, como también sucede en Psilotum Sw. y Ophioglossum L. (Pettitt, 1979;Schraudolf, 1984;Uehara & Kurita, 1986Lugardon, 1990).…”

Section: Discussionunclassified

Esporogénesis, esporodermo y ornamentación de esporas maduras en Lycopodiaceae

Barón

Rolleri

Passarelli

et al. 2014

RBT

View full text Add to dashboard Cite

Sporogenesis, sporoderm and mature spore ornamentation in Lycopodiaceae. Studies on reproductive aspects, spore morphology and ultrastructure of Lycopodiaceae are not very common in the scientific literature, and constitute essential information to support taxonomic and systematic relationships among the group. In order to complete existing information, adding new and broader contributions on these topics, a comparative analysis of the sporogenesis ultrastructure, with emphasis on cytological aspects of the sporocyte coat development, tapetum, monoplastidic and polyplastidic meiosis, sporoderm ontogeny and ornamentation of the mature spores, was carried out in 43 taxa of eight genera of the Lycopodiaceae: Austrolycopodium, Diphasium, Diphasiastrum, Huperzia (including Phlegmariurus), Lycopodium, Lycopodiella, Palhinhaea and Pseudolycopodiella growing in the Andes of Colombia and the Neotropics. For this study, the transmission electron microscopy (TEM) samples were collected in Cauca and Valle del Cauca Departments, while most of the spores for scanning electron microscopy (SEM) analysis were obtained from herbarium samples. We followed standard preparation procedures for spore observation by TEM and SEM. Results showed that the sporocyte coat is largely composed by primary wall components; the sporocyte develop much of their metabolic activity in the production of their coat, which is retained until the spores release; protective functions for the diploid cells undergoing meiosis is postulated here for this layer. The abundance of dictyosomes in the sporocyte cytoplasm was related to the formation and development of the sporocyte coat. Besides microtubule activity, the membrane of sporocyte folds, associated with electrodense material, and would early determine the final patterns of spore ornamentation. Monoplastidic condition is common in Lycopodium s.l., whereas polyplastidic condition was observed in species of Huperzia and Lycopodiella s. l.. In monoplastidic species, the tapetum presents abundant multivesicular bodies, while in polyplastidic species, the secretory activity of the tapetum is less intense. Sporoderm development is centripetal, exospore is the first formed layer, then the endospore and, if present, perispore is the final deposited layer. Adult spores of the Lycopodiaceae showed two patterns of ornamentation: negative or caviform (foveolate spores) and positive or muriform ornamentation, the latter with two subtypes (rugate and reticulate spores). The spores of Huperzia are characteristically foveolate, the rugate spores were found in a few species of Huperzia and in all of the Lycopodiella s. l. taxa studied, while Lycopodium s.l. spores bear reticulate ornamentation. Numerous ornamentation traits are diagnostic at the specific level. The types of ornamentation found do not support the recent extreme fragmentation of the family in several genera, but could match, a priori, with the idea of three subfamilies. The findings of sporogenesis, extremely similar in all taxa studied, point more to con...

show abstract

Section: Discussionunclassified

Esporogénesis, esporodermo y ornamentación de esporas maduras en Lycopodiaceae

Barón

Rolleri

Passarelli

et al. 2014

RBT

View full text Add to dashboard Cite

show abstract

“…En los helechos se ha determinado que los triacilgliceroles pueden llegar a constituir entre el 25-79% del peso seco de las esporas (Gullvag, 1969;Gemmrich, 1977;Randi & Felippe, 1988;Raghavan, 1989;Ballesteros & Walters, 2007;Ballesteros 2011;Gabriel, Galán & Prada, 2011). Sersic (1983), Lugardon (1990), Uehara & Kurita (1991) y Rincón et al (2009), observaron abundantes reservas lipí-dicas en el citoplasma de los esporocitos y las esporas de algunas especies de Lycopodiaceae.…”

Section: Mucopolisacáridos áCidosunclassified

Ontogenia de los esporangios, formación y citoquímica de esporas en licopodios (Lycopodiaceae) colombianos

Barón

Rolleri

Guarin

et al. 2014

RBT

View full text Add to dashboard Cite

Ontogeny of the sporangium, spore formation and cytochemistry in Colombian Lycopodials (Lycopodiaceae). Studies on reproductive aspects of Lycopodiaceae are not very abundant in the scientific literature, and constitute essential information to support taxonomic and systematic relationships among the group. Here we present a detailed study of the ontogeny of sporangia and sporogenesis, and the chemical determination of several compounds generated during spore formation. The analyses were performed in 14 taxa of six genera of the family, Diphasiastrum, Diphasium, Huperzia (a genus which is treated here including Phlegmariurus), Lycopodiella, Lycopodium and Palhinhaea. Specimens were collected in three departments from the Colombian Andes between 1 454-3 677m altitude. Ontogeny was studied in small, 1cm long pieces of strobili and axis, which were fixed in glutaraldehyde or FAA, dehydrated in alcohol, embedded in LR White, sectioned in 0.2-0.5μm and stained with toluidine blue (TBO), a metachromatic dye that allows to detect both sporopollenin and lignin or its precursors, during these processes. For other studies, paraplast plus-embedded sections (3-5μm) were stained with safranin-fast green and alcian blue-hematoxylin. Chemical tests were also conducted in sections of fresh sporangia at different stages of maturity using alcian blue (mucopolysaccharides), Lugol solution (starch), Sudan III (lipids), phloroglucinol (lignin) and orcein (chromosomes). Sections were observed with photonic microscope equipped with differential interference contrast (DIC) and fluorescence microscopy (for spore and sporangium walls unstained). Strobili and sporangia were dehydrated with 2.2 dimethoxypropane, critical point dried and coated with gold for scanning electron microscopy (SEM). Our results indicated that the ontogeny of sporangia and sporogenesis were very similar to the previously observed in Huperzia brevifolia. Cutinisation occurs in early stages of development of sporangium cell walls, but in their final stages walls become lignified. As for the sporoderm development, the exospore is the first layer formed, composed by sporopollenin. The endospore deposits as a thin inner layer composed of cellulose, pectin and carboxylated polysaccharides. The perispore, if present, deposits at last. Mucopolysaccharides were found on the sporocyte coat and its abundance in sporangial cavity persists up to the immature tetrads stage, and then disappears. The lipids were abundant in the sporocytes, tetrads and spores, representing the main source of energy of the latter. In contrast, starch is not detected in the spores, but is abundant in premeiotic sporocytes and immature tetrads, developmental stages of high cellular metabolic activity. Intrinsic fluorescence corroborates the presence of lignin and cutin in the sporangium wall, while the sporopollenin is restricted to the exospore. The transfusion cells and the perispore are not always present. However, the processes of ontogeny and sporogenesis are extremely similar througho...

show abstract

“…Over the last decade, the importance of fern preservation has been considered more seriously (Quintanilla et al 2002;Pence 2008a, b;Li et al 2010;Barnicoat et al 2011;Ballesteros 2011;Gabriel y Galán and Prada 2011;Ibars and Estrelles 2012;Shi 2014, 2015). Among those discussed, species belonging to the family Osmundaceae takes a special place.…”

Section: Introductionmentioning

confidence: 99%

The effect of moisture content and temperature on spore aging in Osmunda regalis

et al. 2015

View full text Add to dashboard Cite

For spores, like seeds, the moisture level and storage temperature seem to be crucial factors responsible for their survival. However, in chlorophyllous spores in particular, the problem is not yet fully understood. The aim of this study was to investigate the effect of moisture content (MC; 6.6 and 4.6 %) and storage temperature (15 and -196°C) on spore germination and gametophyte development in Osmunda regalis. The MC (fresh weight basis) in freshly released spores was 7.5 %, and decreased to 6.6 and 4.6 % during 2 weeks of spore storage at 42 and 18 % relative humidity, respectively. Those spores germinated at 99.9 % within 28 h. The spores with 6.6 and 4.6 % MC were used for the storage at 15 and -196°C. The deterioration of spores, maintained with 6.6 % MC, proceeds within 1.5 years of storage at 15°C, starting with month 8. For the spores with 4.6 % MC serious disturbances in germination and capacity to gametophyte development were postponed for more than 6 months. The time required for spore germination increased with the age of the spores, ranging from 28 h in fresh spores to 10 days in spores stored for more than 11 months. Following 7-year-long cryostorage, spore viability remained at 99.9 %, the time taken for germination remained unaltered and gametophyte development was normal. The viability and vigor of spores were directly correlated with their age, the moisture content and storage temperature.Keywords Germination Á Liquid nitrogen Á Long-term cryostorage Á Spore equilibrium relative humidity

show abstract

Conservation of Fern Spores

Cited by 15 publications

References 37 publications

Esporogénesis, esporodermo y ornamentación de esporas maduras en Lycopodiaceae

Esporogénesis, esporodermo y ornamentación de esporas maduras en Lycopodiaceae

Ontogenia de los esporangios, formación y citoquímica de esporas en licopodios (Lycopodiaceae) colombianos

The effect of moisture content and temperature on spore aging in Osmunda regalis

Contact Info

Product

Resources

About