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1
Elizabeth, Julie I., e T. Sheela Paul. "Growth and yield of oyster mushrooms (Pleurotus spp.) on organically amended agro wastes". INTERNATIONAL JOURNAL OF PLANT PROTECTION 13, n. 2 (15 ottobre 2020): 160–65. http://dx.doi.org/10.15740/has/ijpp/13.2/160-165.
Testo completoAbstract (sommario):
The present experiment was conducted to identify the best organic amendment on the growth and yield of five species of oyster mushrooms viz.,Pleurotus florida, P. sajor-caju, P. eous, P. tuber-regium and Hypsizygus ulmarius by using organic amendments like rice bran, dry azolla, Neem cake, vermiwash and dry biogas slurry at three different concentrations. The effect of organic amendments on the number of days for sporophore formation, number and weight of sporophores varied according to the mushroom species. Results revealed that except dry biogas slurry, all organic amendments had superior effect in reducing number of days for sporophore formation, increasing the number of sporophores and yield. Effect of organic amendments on the yield of oyster mushrooms showed that all organic amendments except dry biogas slurry performed well with more number and weight of sporophores. The number of days for sporophore formation varied between 16.5 to 20.8 days in P. eous, 19.5 to 39 days in P. tuber-regium and 17.5 to 36.8 days in H. ulmarius. In P. florida and P. eous highest yield of 350.3g and 379g, respectively obtained from paddy straw amended with 1 per cent Neem cake. P. sajor-caju gave the maximum yield of 405.3g in 5 per cent rice bran. The maximum yield of 134.8g was recorded in P. tuber-regium when treated with 4 per cent rice bran whereas paddy straw amended with 6 per cent dry azolla gave highest yield of 218.3g in H. ulmarius.
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C. T. Kumbhar, D. Godse, e A. C. Jadhav L. S. Shitole. "Effect of Growth Regulators and Micronutrients on Growth and Yield of Pleurotus sajor-caju". International Journal of Current Microbiology and Applied Sciences 10, n. 12 (10 dicembre 2021): 240–50. http://dx.doi.org/10.20546/ijcmas.2021.1012.028.
Testo completoAbstract (sommario):
The present investigation was conducted to study the effect of various growth regulators and micronutrients on growth and yield of Pleurotus sajor-caju. Results of the research explicitly indicated that the growth regulators and micronutrients experimented at different concentrations, targeting at stimulating growth and sporophore yield of Pleurotus sajor-caju, displayed significantly diverse response to in vitro colony diameter of the fungus, days required for spawn run, pinhead formation, first harvest of sporophores, yield of sporophores and biological efficiency. However, among the growth regulators used, gibberellic acid (GA) @ 20 and 15 ppm significantly improved the colony diameter (90 and 89.98 mm) in in vitro study; reduced the period required for spawn running (13 and 13.5 days), pinhead formation (16 and 16.5), and first harvest (18.5 and 19); augmented the total sporophore yield (858.25 and 855 g/kg dry substrate) and biological efficiency (85.83 and 85.5%). Mixture of micronutrients was ineffective in augmenting the foregoing traits. From the present investigation it is concluded that, spraying of gibberellic acid at 20 and 15 ppm concentrations on cultivation substrate, at the time of spawning, is highly beneficial for obtaining maximum yield of Pleurotus sajor-caju.
3
Latgé, J. P., D. F. Perry, M. C. Prévost e R. A. Samson. "Ultrastructural studies of primary spores of Conidiobolus, Erynia, and related Entomophthorales". Canadian Journal of Botany 67, n. 9 (1 settembre 1989): 2576–89. http://dx.doi.org/10.1139/b89-333.
Testo completoAbstract (sommario):
Wall development during primary spore formation, discharge, and germination of Entomophthorales is emphasized in ultrastructural studies of Conidiobolus, Entomophaga, Neozygites, and Erynia. In the fungi examined, spore and sporophore walls consist of a thick, electron-translucent inner layer and a thin, electron-dense outer layer. During spore formation, cytoplasm of the supporting sporophore cell migrates into the spore initial. As the former cell empties, a septum develops. Discharge is caused by inversion of the papillum, which lacks the electron-dense layer. Only in Erynia did the two spore wall layers separate upon impact. Intracytoplasmic organization of the primary spore is typical of the Zygomycotina; the morphology of organelles was characteristic of species, whereas nuclear ultrastructure was consistent within genera. Conidiobolus nuclei have a prominent nucleolus that lacks heterochromatin, in contrast with the other genera where large patches of heterochromatin were observed. Upon germination, no rupture of the spore outer layer was observed other than at points of germ tube emergence. The germ tube wall was continuous with the inner spore wall layer. The results are discussed in reference to Entomophthorales taxonomy and definition of the terms conidium and monosporous sporangiolum.
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Combet, Emilie, Janey Henderson, Daniel C. Eastwood e Kerry S. Burton. "Influence of Sporophore Development, Damage, Storage, and Tissue Specificity on the Enzymic Formation of Volatiles in Mushrooms (Agaricus bisporus)". Journal of Agricultural and Food Chemistry 57, n. 9 (13 maggio 2009): 3709–17. http://dx.doi.org/10.1021/jf8036209.
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Khan, Foziya, e Ramesh Chandra. "EFFECT OF PHYSIOCHEMICAL FACTORS ON FRUITING BODY FORMATION IN MUSHROOM". International Journal of Pharmacy and Pharmaceutical Sciences 9, n. 10 (2 ottobre 2017): 33. http://dx.doi.org/10.22159/ijpps.2017v9i10.20086.
Testo completoAbstract (sommario):
Objective: Fungi are heterotrophs and are involved in decomposition, nutrient cycling and nutrient transport, and are indispensable for achieving sustainable development. Mushrooms are the fungi with a distinctive fruiting body. Mushrooms are produced all over the world. In India, Punjab is the leading mushroom growing state. Mushrooms are rich sources of proteins, vitamins and minerals. Different types of immunoceuticals like lentinan, schizophyllan, active hexose correlated compound (AHCC) etc. have also been prepared from various mushrooms. The present review work highlights important observations in the area of mushroom. Methods: This review also shows that how several factors affect the fruiting body formation of mushrooms, which includes physiological (composition of culture media) and environmental factors (light, temperature, salinity, etc.). There are different factors like light, temperature etc. which affects the fruiting body development.Results: It has been found that, light has positive effects on hyphal aggregation and fruiting body maturation. It has been found that in oyster mushroom, light is essential for both normal expansion of pileus and in spore formation. It has been found that length of Stipe and the diameter of cap decreases with an increase in the concentration of CO2. Also, there is a range of temperature within which sporophore development occurs. The composition of media affects the growth of mushrooms too. It’s important to maintain a balance between carbon and nitrogen sources for induction of the fruiting body.Conclusion: There are different environmental factors affecting the fruiting body development of mushrooms. Hence, by adjusting various factors like temperature, light, media composition production of mushrooms can be increased.
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Ficke, Andrea, David M. Gadoury, Robert C. Seem e Ian B. Dry. "Effects of Ontogenic Resistance upon Establishment and Growth of Uncinula necator on Grape Berries". Phytopathology® 93, n. 5 (maggio 2003): 556–63. http://dx.doi.org/10.1094/phyto.2003.93.5.556.
Testo completoAbstract (sommario):
Grape berries become resistant to powdery mildew early in development and are nearly immune to infection within 4 weeks after bloom. In this study, ontogenic resistance did not reduce attachment, germination, or appressorium formation of Uncinula necator on 3- to 4-week-old berries of Vitis vinifera ‘Chardonnay’ or 3-week-old berries of V. labruscana ‘Concord’. Pathogen ingress halted at the cuticle before formation of a penetration pore. As berries aged, hyphal elongation and colony growth slowed until finally no secondary hyphae formed on fully resistant berries. More appressoria formed per unit of hyphal length as berries aged, indicating that failure to penetrate older berries led to increased attempts to penetrate resistant fruit. Additionally, hyphae within the colonies began to die as berries aged. Finally, the number of degree-hours between germination and sporulation of the colony (latent period) increased and sporophore density decreased with berry age at time of inoculation. Thus, ontogenic resistance both slows, and eventually halts disease development on grape berries, and limits the likelihood of spread by reducing absolute supply of conidia and delaying their formation. It furthermore has a consistent, stable, and predictable impact on grape powdery mildew and operates in a similar fashion and to a similar degree in both V. labruscana and V. vinifera, although at a slightly earlier phenological stage in V. labruscana.
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Annepu, Sudheer Kumar, Sharma VP, Anupam Barh, Satish Kumar, Mahantesh Shirur e Shwet Kamal. "Effects of genotype and growing substrate on bio-efficiency of gourmet and medicinal mushroom, Lentinula edodes (Berk.) Pegler". Bangladesh Journal of Botany 48, n. 1 (31 marzo 2019): 129–38. http://dx.doi.org/10.3329/bjb.v48i1.47431.
Testo completoAbstract (sommario):
The preference of a particular strain to a specific substrate in shiitake mushroom was investigated. The effect of different genotypes (DMRO-34, DMRO-23, DMRO-327 and DMRO-388s), substrates (sawdust and wheat straw) and their interactions were found highly significant for yield and yield attributing factors. Strain DMRO-388s recorded the highest bio-efficiency (85.63%) on saw dust (SD) and the strain DMRO-327 with 53.02% on wheat straw (WS). The mycelial colonization was rapid on SD, while the sporophore formation was found earlier on WS. Breakdown of phenolic compounds in the substrate was found much higher in WS particularly with strain DMRO-327. Ability of the strains to degrade lignin content was found higher by the strain DMRO-388s (58.78%) in SD. Hemicellulose concentration decreased in both the substrates with each passing growth stage and it was found much rapid with DMRO-388s after spawn run stage. Of the substrates used, SD gave higher yield over the WS. But the earliness of fruiting on WS can economize the cost of shiitake cultivation as it is cheap and abundantly available.
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Tang, C. M., L. D. Waterman, M. H. Smith e C. F. Thurston. "The cel4 Gene of Agaricus bisporus Encodes a β-Mannanase". Applied and Environmental Microbiology 67, n. 5 (1 maggio 2001): 2298–303. http://dx.doi.org/10.1128/aem.67.5.2298-2303.2001.
Testo completoAbstract (sommario):
ABSTRACT Mannases have industrial uses in food and pulp industries, and their regulation may influence development of the mushrooms of commercially important basidiomycetes. We expressed an Agaricus bisporus cel4 cDNA, which encodes a mannanase, inSaccharomyces cerevisiae and Pichia pastoris. CEL4 had no detectable activity on cellulose or xylan. This gene is the first isolated from this economically important fungus to encode a mannanase. P. pastoris secreted about three times more CEL4 than S. cerevisiae. The removal of the cellulose-binding domain of CEL4 lowered the secreted specific activity by P. pastoris by approximately 97%. The genomic sequence ofcel4 was isolated by screening a cosmid library of A. bisporus C54-carb8. The open reading frame was interrupted by 12 introns. The level of extracellular CEL4 increases dramatically at the postharvest stage in compost extracts of A. bisporus fruiting cultures. In laboratory liquid cultures ofA. bisporus, the activity of CEL4 detected in the culture filtrate reached a maximum after 21 days. The levels of CEL4 broadly mirrored the levels of enzyme activity. In the Solka floc-bound mycelium, CEL4 protein showed a maximum after 2 to 3 weeks of culture and then declined. Changes in CEL4 activity during fruiting-body development suggest that hemicellulose utilization plays an important role in sporophore formation. The availability of the cloned gene will further studies of compost decomposition and the extracellular enzymes that fungi deploy in this process.
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Hermsen, Elizabeth J. "Revisions to the fossil sporophyte record of Marsilea". Acta Palaeobotanica 59, n. 1 (1 giugno 2019): 27–50. http://dx.doi.org/10.2478/acpa-2019-0005.
Testo completoAbstract (sommario):
Abstract The fossil record of Marsilea is challenging to assess, due in part to unreliable reports and conflicting opinions regarding the proper application of the names Marsilea and Marsileaceaephyllum to fossil leaves and leaflets similar to those of modern Marsilea. Specimens examined for this study include material assigned to Marsileaceaephyllum johnhallii, purportedly the oldest fossil record of a Marsilea-like sporophyte from the Lower Cretaceous of the Dakota Formation, Kansas, U.S.A.; leaves and leaf whorls of the extinct aquatic angiosperm Fortuna from several Late Cretaceous and Paleocene localities in western North America; and leaves and leaflets resembling Marsilea from the Eocene Green River Formation, Colorado and Utah, U.S.A. Literature on the fossil record of Marsilea was also reviewed. As a result, several taxonomic changes are proposed. Marsileaceaephyllum johnhallii is reinterpreted as an aquatic angiosperm that shares some architectural features with the genus Fortuna, although Marsileaceaephyllum is here maintained as a distinct genus with an emended diagnosis; under this reinterpretation, the name Marsileaceaephyllum can no longer be applied to sporophyte organs with affinities to Marsileaceae. Three valid fossil Marsilea species are recognized on the basis of sporophyte material that includes characteristic quadrifoliolate leaves and reticulate-veined leaflets: Marsilea campanica (J. Kvaček & Herman) Hermsen, comb. nov., from the Upper Cretaceous Grünbach Formation, Austria; Marsilea mascogos Estrada-Ruiz et al., from the Upper Cretaceous Olmos Formation, Mexico; and Marsilea sprungerorum Hermsen, sp. nov., from the Eocene Green River Formation, U.S.A. The species are distinguished from one another based on leaflet dimensions. Leaves from the Eocene Wasatch Formation, U.S.A., are transferred from Marsileaceaephyllum back to Marsilea, although not assigned to a fossil species. Finally, an occurrence of Marsilea from the Oligocene of Ethiopia is reassigned to Salvinia. A critical evaluation of the fossil record of Marsilea thus indicates that (1) the oldest fossil marsileaceous sporophytes bearing Marsilea-like leaves are from the Campanian; (2) only four credible records of sporophyte material attributable to Marsilea are known; and (3) the oldest dispersed Marsilea spores are known from the Oligocene.
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Sundberg, Sebastian. "Sporophyte production and spore dispersal phenology in Sphagnum: the importance of summer moisture and patch characteristics". Canadian Journal of Botany 80, n. 5 (1 maggio 2002): 543–56. http://dx.doi.org/10.1139/b02-060.
Testo completoAbstract (sommario):
Sporophyte production in Sphagnum was followed annually in 80 permanent 1-m2 plots at the bog expanse of a pristine mire during 19931999 and in 60 plots in peat pits abandoned 50 years ago during 19961999 in east central Sweden. The nine most abundant Sphagnum species produced sporophytes, with mean annual production ranging from 0.64 to 20 sporophytes/dm2 of cover among species. An estimated mean of 16 million Sphagnum spores/m2 mire area was produced annually at both mires. At the pristine mire, sporophyte production was positively related to the amount of precipitation the previous summer, suggesting that gametangium formation is especially sensitive to summer droughts. At the wetter peat pits, the amount of precipitation during spring in the year of sporophyte formation appeared more important, probably by positively affecting male gamete dispersal and fertilization. Larger patches had a higher probability of producing sporophytes at least once, showing areas with both sexes present among dioecious species, and thus giving an indication of clone size. Only slight differences in sporophyte production were found between the two mires, apart from effects of hydrological conditions and patch size. This indicates numerous colonizations at the peat pits. Summer droughts affected sporophyte maturation negatively by drying out sporophytes prematurely. Spore release phenology differed among species by up to a month and lasted from the beginning of July until the end of August. The early timing of spore dispersal in the most drought-sensitive, lawn-inhabiting sphagna should reduce the risk of sporophytes drying out prematurely during summer droughts.Key words: bryophyte, long-term study, mire, model, sexual reproduction, strategy.
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Kai, Tomoki, Kazumi Nimura, Hajime Yasui e Hiroyuki Mizuta. "Regulation of Sorus Formation by Auxin in Laminariales Sporophyte". Journal of Applied Phycology 18, n. 1 (febbraio 2006): 95–101. http://dx.doi.org/10.1007/s10811-005-9020-8.
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Kawakami, Suzue M., Michio Ito e Shogo Kawakami. "Apogamous sporophyte formation in a fernPteris multifida and its characteristics". Journal of Plant Research 108, n. 2 (giugno 1995): 181–84. http://dx.doi.org/10.1007/bf02344342.
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Hedenäs, Lars, e Irene Bisang. "Episodic but ample sporophyte production in the moss Drepanocladus turgescens (Bryophyta: Amblystegiaceae) in SE Sweden". Acta Musei Silesiae, Scientiae Naturales 68, n. 1-2 (1 luglio 2019): 83–93. http://dx.doi.org/10.2478/cszma-2019-0009.
Testo completoAbstract (sommario):
Abstract In the Baltic area, the long-lived dioicous wetland moss Drepanocladus turgescens (T.Jensen) Broth. produces sporophytes rarely and at irregular intervals. Based on surveys of sporophyte occurrences at 13 sites in two regions in northern Gotland (Sweden) during three to five years, we ask: (1) Is sporophyte formation associated with precipitation and a precipitation index that considers the dry periods during July-August of the preceding year, when gametangia are formed and fertilization occurs? (2) Does the estimated spore output suffice for the species’ long-term persistence of the (Northern) European population species? In one of the study regions, where D. turgescens occurs in depressions, sporophyte formation was associated with the two precipitation parameters. In the other study region, with relatively higher precipitation and exposed occurrences on a slightly sloping bedrock with very little accumulated soil, no such association existed. We suggest that this lack of weather effects results from that the exposed rock habitat requires longer continuously wet periods than the depression habitat to allow for gametangia initiation and development, and fertilisation. Average spore production for six spore capsules, from three Gotland localities was 181,000. Based on the sporophyte counts during the survey years, we estimated the total reproductive output as 411.5 million spores in 2013, and 42.5 million in 2015, in the two respective study regions. Taken together with data on haplotype patterns and considering observations on recent colonisations, we argue that such a relatively low and episodic regional spore production is sufficient to maintain global populations of long-lived species, even if these occur in specialized and geographically restricted habitats.
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Rolleri, C. H., C. Prada, J. M. Gabriel y Galán, L. M. Passarelli e M. M. Ciciarelli. "Morphology of the sporophyte and gametophyte of the swamp fern, Blechnum serrulatum (Blechnaceae, Pteridophyta)". Australian Journal of Botany 58, n. 6 (2010): 508. http://dx.doi.org/10.1071/bt09238.
Testo completoAbstract (sommario):
In the present paper, we provide a revised, comprehensive description of the sporophyte and gametophyte of the swamp fern, Blechnum serrulatum Rich., from neo- and paleotropical localities. External and internal characters of the sporophyte were analysed, including axes, laminae, pinnae, indusia and spores. Intercellular pectic connections of the parenchyma of the rhizomes are reported for the first time. In stipes, cell walls of the aerenchyma tissue contain filamentous protuberances that are composed primarily of cellulose but contain also fatty substances. The morphology of the gametophyte, from spore germination to gametangia formation, is discussed. The taxonomic significance of the characters is considered, especially in regard to the relationship between B. serrulatum and the closely related B. indicum.
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Kawakami, Suzue M., Shogo Kawakami, Katsuhiko Kondo e Alexander Shmakov. "Cytological studies of Russian Altai ferns and the haploid sporophyte formation". Chromosome Botany 6, n. 2 (2011): 21–23. http://dx.doi.org/10.3199/iscb.6.21.
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Маkоvеi, M. D. "The breeding method and its influence on the intensification of the tomato selection process". Vegetable crops of Russia, n. 5 (30 ottobre 2020): 43–48. http://dx.doi.org/10.18619/2072-9146-2020-5-43-48.
Testo completoAbstract (sommario):
Relevance. The article presents the results of using three different selection methods to obtain new forms of tomato that combine high productivity with resistance to high-temperature stress factor.Methods. Eleven hybrid combinations were used as experimental material. Selections were made starting with the offspring of the F1 generation. Three different methodological approaches were used: 1 – step-by-step alternation of sporophytic-gametophytic selections under high temperature pressure; 2 – only gametophytic selection using heat-treated pollen for pollination; 3 – traditional selections based on a high value of indicators of the studied traits. In each of the variants of the experiment, we studied: the heat resistance of offspring at different stages of ontogenesis – "sporophyte-gametophyte"; the duration of the vegetation period of plants; the fruit formation; the total yield. The offspring of the most stable and productive plants isolated from different hybrid combinations were combined in the populations in each variant of the experiment and a comparative analysis and evaluation of the effectiveness of the methods used was carried out.Results. It is shown that the combination of step-by-step sporophyte-gametophyte selections under the action of high-temperature regimes (43°C and 45°C), at early stages (F1–F3) lead to more stable, productive offspring in F5-F7 both for sporophyte and gametophyte traits, compared to using only gametophyte selections and stronger differences relative to the control variant. The gradual alternation of selections at different stages of ontogenesis also leads to the production of offspring with a shorter period of passage of the phenophases "seedling-flowering" – "floweringmaturation" and a stable manifestation of signs that determine the quality of the fruits. Using only gametophytic selections and traditional methods of selection was less effective than alternating sporophyte-gametophyte ones.Conclusions. The differentiating ability of the selection methods used and their influence on obtaining more resistance and productive genotypes was established. The advantage of the method of step-by-step alternation of sporophyte-gametophyte selections, which led to the production of new lines (118/1, 124/1, 133-11/1, 133-12/1, 134/1, 110/1 and 7/1) with high resistance at different stages of ontogenesis (sporophyte-gametophyte), shorter vegetation period and high fruit-forming capacity in three different years of research (2015-2017).
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Park, Kyungtae, Bo Kook Jang, Ha Min Lee, Ju Sung Cho e Cheol Hee Lee. "An Efficient Method for In Vitro Shoot-Tip Culture and Sporophyte Production Using Selaginella martensii Spring Sporophyte". Plants 9, n. 2 (12 febbraio 2020): 235. http://dx.doi.org/10.3390/plants9020235.
Testo completoAbstract (sommario):
Selaginella martensii, an evergreen perennial fern that is native to South America and New Zealand, is named “frosty fern” because of its beautiful white-colored leaves and it is used as an ornamental plant. Efficient propagation methods for this species have not been developed. We aimed to develop an efficient propagation method for S. martensii through in vitro culture. We investigated culture conditions that are suitable for shoot-tip proliferation and growth. The optimum shoot-tip culture conditions were determined while using Murashige and Skoog (MS) medium (quarter, half, full, or double strength) and macronutrients (sucrose and two nitrogen sources) at various concentrations. In MS medium, the shoot tips formed a maximum of 6.77 nodes per explant, and each node formed two new shoot tips (i.e., 26 or 64 shoot tips). When using branching segments containing an angle meristem, the shoot-to-rhizophore formation ratio could be controlled by medium supplementation with plant-growth regulators. Sporophytes that were grown from shoot tips in vitro were acclimated in ex vitro soil conditions and successfully survived in the greenhouse. Numerous shoot tips could be obtained from in vitro-grown sporophytes and be proliferated ex vitro to produce a large number of plants. This method provides a way of shortening the time that is required for producing a large stock of S. martensii planting material.
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Takeno, Kiyotoshi, e Masaki Furuya. "Sporophyte formation in experimentally-induced unisexual female and bisexual gametophytes ofLygodium japonicum". Botanical Magazine Tokyo 100, n. 1 (marzo 1987): 37–41. http://dx.doi.org/10.1007/bf02488418.
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Goller, Katarzyna, e Jan J. Rybczyński. "Gametophyte and sporophyte of tree ferns in vitro culture". Acta Societatis Botanicorum Poloniae 76, n. 3 (2011): 193–99. http://dx.doi.org/10.5586/asbp.2007.022.
Testo completoAbstract (sommario):
Experiments had been carried out on gametophytes and very young fronds of sporophytes with application of Murashige and Skoog (1962) medium. The paper described the results of 15 years in vitro experiments on 16 species of tree ferns belonging to various genera: <em>Blechnum</em>, <em>Cibotium</em>, <em>Cyathea</em> and <em>Dicksonia</em>. Genus <em>Cyathea</em> was represented by: <em>C. australis</em> (R.Br.) Domin., <em>C. capensis</em> (L.f.) Sm., <em>C. cooperi</em> (F.Muell.) Domin, <em>C. brownii</em> Domin, <em>C. dealbata</em> (G.Forest) Sw., <em>C. dregei</em> Kunze, <em>C. leichhardtiana</em> (F.Muell.) Copel., <em>C. robertsiana</em> (F.Muell.) Domin., <em>C. schanschin</em> Mart., <em>C. smithii</em> Hook.f. and <em>Cyathea</em> sp. In case of genus <em>Dicksonia</em> only two species were introduced into our experiments: <em>D. fibrosa</em> Colenso and <em>D. sellowiana</em> Hook.. Taxa <em>Blechnum</em> was presented by <em>B. brasiliense</em> Desv. and <em>Cibotium</em> by <em>C. glaucum</em> (Sm.) Hook. and Arn. and <em>C. schiedei</em> Schltdl. and Cham.. The studied species presented various responses on culture conditions depending on the level of stage of development. Time required for spores germination differed between species and took from only a few to 16 weeks. Prothalium formations showed various types of growth presented by marginal meristems. For all investigated species long term gametophyte in vitro cultures was established. Mature gametophyte possessed functional antheridia and archegonia. Spontaneous fertilization helped to establish the culture of young sporophytes. For all species the ex vitro culture in greenhouse collection was established. Manipulation of sucrose content in the medium stimulated the multiplication of gametophytes, but its lack induced formation of gemmae. Apospory was observed when culture of very young fronds was extended for 6 months and new generation of gametophytes was developed. Finally, sporophytes of 12 species were obtained and they have been growing in our greenhouse.
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Xingxue, Li, e J. F. Rigby. "Further contributions to the study of the Qubu Flora from southern Xizang (Tibet)". Journal of Palaeosciences 44 (31 dicembre 1995): 38–47. http://dx.doi.org/10.54991/jop.1995.1200.
Testo completoAbstract (sommario):
The taxonomy of Glossopteris species occurring in the Qubu Formation is reviewed; G. xizangensis is proposed. Samaropsis xizangensis is proposed for seeds found attached to G. xizangensis. An affiliation with the Glossopteris flora of the Mamal Formation, Kashmir appears valid although the number of distinctive species in common is reduced to Glossopteris dingriensis.
Aspects of sporophyte taxa are reviewed in the light of doubts concerning affiliations proposed previously. Additional specimens are needed before problems can be resolved concerning species of Sphenophyllum or Trizygia, Austroannularia, Cladophlebis and Pecopteris. Scale leaf remains have not been named.
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Jang, Bo Kook, Ju Sung Cho e Cheol Hee Lee. "Propagation methods for gametophyte proliferation and sporophyte formation in silver cloak fern (Cheilanthes argentea)". Horticulture, Environment, and Biotechnology 60, n. 3 (17 maggio 2019): 435–42. http://dx.doi.org/10.1007/s13580-019-00128-6.
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Sundari, M., Asir Benniamin, Doss Jesubalan e Kaushik Sarkar. "In vitro propagation of Asplenium aethiopicum through tissue culture". Journal of Non-Timber Forest Products 28, n. 2 (15 gennaio 2022): 39–42. http://dx.doi.org/10.54207/bsmps2000-2022-21a0h6.
Testo completoAbstract (sommario):
Poor viability of spores and germination and slow growth in conventional vegetative propagation are major constraints in the in vitro culture of Asplenium aethiopicum, an important medicinal fern. In the present study, a procedure for in vitro propagation of this endangered fern through croziers has been established. Maximum sporophytes efficiency was obtained on KC media supplemented with growth regulators such as 0.5mg/l NAA & 0.5mg/l 2,4-D with 2 sucrose under photoperiod condition. Maximum frequency (33.2%) of callus formation and germination of sporophyte was observed on KC medium with growth regulators.
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Renzaglia, Karen Sue, R. Joel Duff, Daniel L. Nickrent e David J. Garbary. "Vegetative and reproductive innovations of early land plants: implications for a unified phylogeny". Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 355, n. 1398 (29 giugno 2000): 769–93. http://dx.doi.org/10.1098/rstb.2000.0615.
Testo completoAbstract (sommario):
As the oldest extant lineages of land plants, bryophytes provide a living laboratory in which to evaluate morphological adaptations associated with early land existence. In this paper we examine reproductive and structural innovations in the gametophyte and sporophyte generations of hornworts, liverworts, mosses and basal pteridophytes. Reproductive features relating to spermatogenesis and the architecture of motile male gametes are overviewed and evaluated from an evolutionary perspective. Phylogenetic analyses of a data set derived from spermatogenesis and one derived from comprehensive morphogenetic data are compared with a molecular analysis of nuclear and mitochondrial small subunit rDNA sequences. Although relatively small because of a reliance on water for sexual reproduction, gametophytes of bryophytes are the most elaborate of those produced by any land plant. Phenotypic variability in gametophytic habit ranges from leafy to thalloid forms with the greatest diversity exhibited by hepatics. Appendages, including leaves, slime papillae and hairs, predominate in liverworts and mosses, while hornwort gametophytes are strictly thalloid with no organized external structures. Internalization of reproductive and vegetative structures within mucilage–filled spaces is an adaptive strategy exhibited by hornworts. The formative stages of gametangial development are similar in the three bryophyte groups, with the exception that in mosses apical growth is intercalated into early organogenesis, a feature echoed in moss sporophyte ontogeny. A monosporangiate, unbranched sporophyte typifies bryophytes, but developmental and structural innovations suggest the three bryophyte groups diverged prior to elaboration of this generation. Sporophyte morphogenesis in hornworts involves non–synchronized sporogenesis and the continued elongation of the single sporangium, features unique among archegoniates. In hepatics, elongation of the sporophyte seta and archegoniophore is rapid and requires instantaneous wall expandability and hydrostatic support. Unicellular, spiralled elaters and capsule dehiscence through the formation of four regular valves are autapomorphies of liverworts. Sporophytic sophistications in the moss clade include conducting tissue, stomata, an assimilative layer and an elaborate peristome for extended spore dispersal. Characters such as stomata and conducting cells that are shared among sporophytes of mosses, hornworts and pteridophytes are interpreted as parallelisms and not homologies. Our phylogenetic analysis of three different data sets is the most comprehensive to date and points to a single phylogenetic solution for the evolution of basal embryophytes. Hornworts are supported as the earliest divergent embryophyte clade with a moss/liverwort clade sister to tracheophytes. Among pteridophytes, lycophytes are monophyletic and an assemblage containing ferns, Equisetum and psilophytes is sister to seed plants. Congruence between morphological and molecular hypotheses indicates that these data sets are tracking the same phylogenetic signal and reinforces our phylogenetic conclusions. It appears that total evidence approaches are valuable in resolving ancient radiations such as those characterizing the evolution of early embryophytes. More information on land plant phylogeny can be found at: http://www.science.siu.edu/landplants/index.html.
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Kim, Seohyun, Jin-Sup Park, Jaehoon Lee, Kiseok Keith Lee, Ok-Sun Park, Hee-Seung Choi, Pil Joon Seo et al. "The DME demethylase regulates sporophyte gene expression, cell proliferation, differentiation, and meristem resurrection". Proceedings of the National Academy of Sciences 118, n. 29 (15 luglio 2021): e2026806118. http://dx.doi.org/10.1073/pnas.2026806118.
Testo completoAbstract (sommario):
The flowering plant life cycle consists of alternating haploid (gametophyte) and diploid (sporophyte) generations, where the sporophytic generation begins with fertilization of haploid gametes. In Arabidopsis, genome-wide DNA demethylation is required for normal development, catalyzed by the DEMETER (DME) DNA demethylase in the gamete companion cells of male and female gametophytes. In the sporophyte, postembryonic growth and development are largely dependent on the activity of numerous stem cell niches, or meristems. Analyzing Arabidopsis plants homozygous for a loss-of-function dme-2 allele, we show that DME influences many aspects of sporophytic growth and development. dme-2 mutants exhibited delayed seed germination, variable root hair growth, aberrant cellular proliferation and differentiation followed by enhanced de novo shoot formation, dysregulation of root quiescence and stomatal precursor cells, and inflorescence meristem (IM) resurrection. We also show that sporophytic DME activity exerts a profound effect on the transcriptome of developing Arabidopsis plants, including discrete groups of regulatory genes that are misregulated in dme-2 mutant tissues, allowing us to potentially link phenotypes to changes in specific gene expression pathways. These results show that DME plays a key role in sporophytic development and suggest that DME-mediated active DNA demethylation may be involved in the maintenance of stem cell activities during the sporophytic life cycle in Arabidopsis.
25
Jang, Bo Kook, Ju Sung Cho e Cheol Hee Lee. "Synthetic Seed Technology Development and Production Studies for Storage, Transport, and Industrialization of Bracken Spores". Plants 9, n. 9 (22 agosto 2020): 1079. http://dx.doi.org/10.3390/plants9091079.
Testo completoAbstract (sommario):
Bracken fern (Pteridium aquilinum var. latiusculum (Desv.) Underw. ex A. Heller) has long been grown industrially in South Korea. Conventional propagation methods, including planting rhizomes and in vitro seedling culture, are labor intensive and expensive, and thus not commercially suitable. We aimed to develop a system to produce synthetic seeds using fern spores (SFS). Synthetic seeds were prepared by mixing bracken spores and alginate matrix. Spore germination and gametophyte and sporophyte growth and development from SFS proceeded normally. Spore density affected gametophyte and sporophyte numbers. SFS prepared using cold (4 °C) long-term storage spores (even 7-year-old spores) could effectively form sporophytes. The highest germination was observed at 25 °C. Soaking-treated SFS successfully formed sporophytes, even after 30 days of storage at 4 °C; indeed, sporophytes formed even after five days of storage at 25 °C during transport conditions. SFS were sown in plug trays for commercial use. Young sporophytes grown from plug seedlings were greenhouse cultivated, and transplanting within eight weeks was effective for root growth and growing-point formation. Developing synthetic seeds is a feasible solution for facilitating efficient transport and the handling of small-sized fern spores; furthermore, this SFS technology provides the basis for fern seedling culture and fern spore industrialization.
26
Peng, Li, Zhen Kai Li, Xiao Li Ding e Hui Qiao Tian. "Advances in the study of egg activation of higher plants". Zygote 26, n. 6 (dicembre 2018): 435–42. http://dx.doi.org/10.1017/s0967199418000539.
Testo completoAbstract (sommario):
SummaryFertilization in higher plants induces many structural and physiological changes in the fertilized egg, and represents the transition from the haploid female gamete to the diploid zygote, the first cell of a sporophyte. Some changes are induced extremely rapidly following fusion with sperm cells and are the preclusions of egg activation. This review focuses on the early changes that occur in the egg after fusion with sperm cells, but before nuclear fusion. Reported changes include cell shrinkage, cell wall formation, polarity change, oscillation in Ca2+ concentration, and DNA synthesis. In addition, the current understanding of egg activation is summarized and the possible functional relevance of the changes is explored.
27
Mizuta, Hiroyuki, Kazumi Nimura e Hirotoshi Yamamoto. "Inducible Conditions for Sorus Formation of the Sporophyte Discs of Laminaria japonica Areschoug (Phaeophyceae)". Fisheries science 65, n. 1 (1999): 104–8. http://dx.doi.org/10.2331/fishsci.65.104.
Testo completo
28
ØDegaard, Siri, Kjersti SjØTun, Tor Eiliv Lein e Eyvind Aas. "Sporophyte formation ofLaminaria hyperborea(Laminariales, phaeophyceae) related to photon doses of blue light in the sea". Sarsia 83, n. 4 (9 ottobre 1998): 301–8. http://dx.doi.org/10.1080/00364827.1998.10413689.
Testo completo
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Pangua, Emilia, Santiago Pajarón e Luis G. Quintanilla. "Fitness of an allopolyploid rupicolous fern compared with its diploid progenitors: from sporogenesis to sporophyte formation". American Journal of Botany 106, n. 7 (12 giugno 2019): 984–95. http://dx.doi.org/10.1002/ajb2.1314.
Testo completo
30
Banks, J. A. "Sex-determining genes in the homosporous fern Ceratopteris". Development 120, n. 7 (1 luglio 1994): 1949–58. http://dx.doi.org/10.1242/dev.120.7.1949.
Testo completoAbstract (sommario):
Haploid Ceratopteris gametophytes are either hermaphroditic or male. The determinate of sex type is the pheromone antheridiogen (ACE) which is secreted by the meristic hermaphrodite and promotes ameristic male development of sexually undetermined gametophytes. Several mutations effecting the sex of the haploid gametophyte have been isolated and are described. The hermaphroditic (her) mutants are insensitive to ACE and develop as meristic hermaphrodites. These mutations effect ameristic male development in the presence of ACE but have no effect on hermaphroditic development. While most her mutations also have no effect on diploid sporophyte development, some partially ACE-insensitive her mutations have profound effects on sporophyte development. The transformer (tra) mutation effects both meristem and archegonia formation and causes the gametophyte to be an ameristic male under conditions that promote hermaphroditic development. The feminization (fem) mutation effects antheridia development in both male and hermaphroditic gametophytes and causes the gametophyte to develop as a meristic female in the absence or presence of the pheromone. The her1 tra1 double mutant is male in the absence or presence of ACE, indicating that tra1 is epistatic to her1. The phenotypes of her1, tra1 and fem1 single gene mutant phenotypes and the her1 tra1 double mutant phenotype are used to deduce a model suggesting how the products of these genes might interact in a regulatory pathway to control sex determination.
31
Konrat, Matt von, Peter de Lange, Juan Larraín, Jörn Hentschel, Benjamin Carter, Jon Shaw e Blanka Shaw. "A small world: Uncovering hidden diversity in Frullania – a new species from Aotearoa-New Zealand". Polish Botanical Journal 58, n. 2 (1 dicembre 2013): 437–47. http://dx.doi.org/10.2478/pbj-2013-0056.
Testo completoAbstract (sommario):
Abstract Frullania is a large and taxonomically complex genus. Here a new Frullania, F. toropuku von Konrat, de Lange & Larraín, sp. nov. is described from New Zealand. Frullania toropuku is placed in F. subg. Microfrullania. The new species is readily recognised by a combination of morphological characters associated with branching, the perianth, sexuality, and sporophyte, which distinguish it from all other New Zealand and regional species of Frullania. However, morphologically F. toropuku most closely resembles the widespread F. rostrata, which might well be regarded as a Southern Hemisphere equivalent of the Holarctic F. tamarisci species-complex in terms of its cryptic diversity. A combination of morphological characters associated with branching, the perianth, sexuality, and sporophyte distinguish F. toropuku from all other New Zealand and regional species of Frullania. A comparison is made between F. toropuku and morphologically allied species of botanical regions outside the New Zealand region and an artificial key is provided. In a prior investigation, maximum parsimony and maximum likelihood analyses of nuclear ribosomal ITS2 and plastidic trnL-trnF sequences from purported related species confirms its independent taxonomic status and corroborates its placement within F. subg. Microfrullania. The ongoing studies of Frullania species-complexes reveal the urgent need for more species-level phylogenies with extensive population sampling to approximate the actual diversity of Frullania, and to elucidate speciation processes and distribution range formation.
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DUCKETT, JEFFREY G., e SILVIA PRESSEL. "The Colorful Phenology of Five Common Terricolous Mosses in London, England". Bryophyte Diversity and Evolution 39, n. 1 (24 luglio 2017): 44. http://dx.doi.org/10.11646/bde.39.1.8.
Testo completoAbstract (sommario):
Other than general statements about ‘fruiting’ seasons, published floras provide little or no instructive information on moss phenology. Moreover, detailed primary data on reproductive cycles are limited to a very few mosses and remain unknown for the majority of the commonest species. Thus we recorded, over a three year period, the reproductive stages of five very common mosses (Bryum capillare, B. radiculosum, Grimmia pulvinata, Schistidium crassipilum and Tortula muralis) growing on walls in London, England, relying throughout on freshly observed materials rather than dried specimens used in most previous studies. In addition to all the stages visible to the naked eye, which we photographed at regular intervals, specimens were examined microscopically for the presence of viable gametangia, young embryos and the condition of the stomata. Each species had its own distinct phenology and an unique sequence of capsule colour changes. In the two Bryum species, gametangium ontogeny, followed by fertilization, takes place in the spring but the embryos remain dormant until the autumn whereas these stages are autumnal in Grimmia pulvinata, Schistidium crassipilum and Tortula muralis with sporophyte development following immediately. Most stages in sporophyte ontogeny occur over the winter months. The time from embryo formation to spore release ranges from over fifteen months in the two Bryum species down to eight months in Schistidium. In all but this last species there is a delay of up to several months between sporophyte maturation and spore release. In Bryum, hygroscopic movements of the annular cells following heavy rain eventually leads to lid shedding. Over the three years of this study the reproductive cycles were generally the same except that damp weather in the autumn promoted capsule expansion in Grimmia and Schistidium and warm dry weather in the spring hastened capsule maturation in Bryum. Whatever the weather conditions, the stomata of the two Bryum species, Grimmia and Tortula were always open suggesting a primary role in capsule desiccation leading to spore discharge rather than the regulation of gaseous exchange.
33
MIR, Ricardo, e Oscar VICENTE. "POLLEN: AN AMAZING MODEL SYSTEM TO STUDY A DISPARATE SERIES OF PLANT BIOLOGICAL PROCESSES". AgroLife Scientific Journal 10, n. 1 (30 giugno 2021): 154–63. http://dx.doi.org/10.17930/agl2021117.
Testo completoAbstract (sommario):
Pollen, the male gametophyte of higher plants, represents an extremely interesting, and peculiar, experimental system for the study of diverse aspects of plant biology, apart from the - obvious - research on gametophytic development in itself. For example, cell cycle progression, as the formation of mature pollen from the microspore mother cells consists in a series of specific, often synchronous cell divisions: meiosis, the asymmetric microspore mitosis and the division of the generative pollen cell. Also, for the study of the interactions between the gametophyte and the sporophyte during pollen development, the formation of the - unusual - pollen wall or intracellular transport processes during pollen tube growth. Instead of dedifferentiating and forming a callus, as normally happens with any isolated plant cell, microspores isolated from the anthers can continue in vitro their normal developmental programme, giving rise to mature, functional pollen. However, triggered by specific stress treatments, microspores and immature pollen grains can switch towards sporophytic development with the formation of (haploid) embryos and plants. These and other unique characteristics of the pollen system will be discussed in this review
34
Babenko, L. M., I. V. Kosakivska e L. V. Voytenko. "Peculiarities of growth and lipoxygenase activity of wild fern Dryopteris filix-mas (L.) Schott". Ukrainian Journal of Ecology 8, n. 1 (5 febbraio 2018): 158–64. http://dx.doi.org/10.15421/2018_201.
Testo completoAbstract (sommario):
<p>We studied the peculiarities of growth, localization and dynamics of lipoxygenase activity in sporophyte organs of wild fern <em>Dryopteris filix-mas </em>(L.) Schott at various stages: intensive growth; sori ripening; spore release; summer vegetation, and vegetation termination. Morphometric analysis showed that the weight of one plant during sporophyte ontogenesis varied from 130 to 150 g. Frond length varied from 11 to 85 cm. Diameter of the overground part of rhizome was 9-10 cm. In the stage of spore release and during the summer vegetation we mentioned 7 fronds on plant, and in the phase of vegetation termination – 18. The plants had the biggest weight in phase of spore release. Following spore release and at the beginning of vegetation termination, the frond weight diminished almost by two times. An intensive elongation of fronds was observed prior to the start of spore release. When fronds unfold and grow the number of segments of the first order increase from 39 to 47 pairs. Frond length in the stage of summer vegetation increased from 4.3 to 11.2 cm (9 pairs), and then it gradually decreased from 10.2 to 0.1 cm (39 pairs) that resulted in the formation of a lanceolate lamina. In the stage of vegetation termination, the fern had 18 fronds, 12 of which remained green, while the rest dried and turned greyish-brown. The frond lamina contained 47 pairs of segments of the first order whose length increased from 4.5 to 10.5 cm, and then it diminished from 9.5 to 0.05 cm. The rhizome weight was in the range of 110.2–115.7 g in all the stages except vegetation termination. The morphological analysis showed that plants had successfully passed all developmental phases, reached their normal dimensions, had a mass spore formation, no external signs of suppression and damages, and this was generally consistent with the highest level of life state assessment. Localization and dynamics of lipoxygenase (LOX) activity in organs of the sporophyte of <em>D. filix-mas </em>have been studied. We registered that fronds contained 13-LOX with рН<sub>opt. </sub>values of 7.2, rhizomes – 9-LOX (рН<sub>opt. </sub>6.5). Peculiarities that were mentioned in localization and dynamics of LOX isoforms catalytic activity in the fern organs at various phases of development suggest that the enzyme might be involved in the regulation of lipid metabolism of growth processes that ensure plant adaptation to the environment. </p><p> </p>
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Sundari, M., A. Benniamin, D. Jesubalan e Rajeshwar Dayal. "In vitro spore germination of Pityrogramma calomelanos - A medicinal fern". Journal of Non Timber Forest Products 28, n. 1 (30 novembre 2021): 23–27. http://dx.doi.org/10.54207/bsmps2000-2021-3ejo69.
Testo completoAbstract (sommario):
Ferns have a great economic value based upon the good ornamental qualities of foliage. Pityrogramma calomelanos (L.) Link. commonly known as ‘Silver fern’, belongs to the family Pteridaceae and is a terrestrial or lithophytic herbaceous fern distributed in the tropical and subtropical regions of the world. It is a medicinally important ornamental fern. The spore germination and developmental pattern of prothallium has been dealt herein with particular emphasis on gametophyte, emergence of antheridia as well as archegonia, their fertilization and turnover of sporophytes. The spores started germinating just after 5 days, whereas thespores sown after 25 days in the similar composition of culture media did not show any germination, emancipating full loss of spore viability. The study of this medicinal fern includes spore germination, gametophyte growth, differentiation sex ontogeny and development of sporophytes. The effect of kinetin and IBA with KC media yielding a high number of sporophyte formations. In addition to the normal turnover of sporophytes in above sets of experiment, it was also observed that the dense spore sowing developed usually small, uniseriate, very occasionally broadened, abnormal gametophytes rather than normal cordate one, which always failed to produce any sporophyte. In vitro raised plants showed 54% of establishment during hardening in the field. The present study has established the reproducible protocol for the ex situ conservation of this Medicinal fern.
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Cvetic, Tijana, Marko Sabovljevic, Aneta Sabovljevic e D. Grubisic. "In vitro culture and apogamy: Alternative pathway in the life cycle of the moss Amblystegium serpens (Amblystegiaceae)". Archives of Biological Sciences 57, n. 4 (2005): 267–72. http://dx.doi.org/10.2298/abs0504267c.
Testo completoAbstract (sommario):
In vitro culture of the moss Amblystegium serpens (Amblystegiaceae) was established on hormone-free Murashige and Skoog (MS) medium that contained a half amount of MS micro- and macro- mineral salts and vitamins, 100 mg/l myoinositol, 30 g/l sucrose, and 0.70% (w/v) agar. Spores were germinated and primary protonema developed on the above medium at 16 h day/8 h night 25?2?C, 60-70% air humidity, and irradiance of 47 ?mol/m2s. Three months after development of primary protonema, seven sporophytes appeared directly from primary protonema without generation alternation. The phenomenon of apogamous sporophyte formation is very rare, both in nature and under in vitro conditions. This is the first report of apogamy induced by Amblystegium serpens.
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Wang, Yuqing, Xiaoxiao Wu, Yongqing Lu, Huimin Fu, Shuqi Liu, Juan Zhao e Chaoan Long. "Ferric Chloride Controls Citrus Anthracnose by Inducing the Autophagy Activity of Colletotrichum gloeosporioides". Journal of Fungi 9, n. 2 (9 febbraio 2023): 230. http://dx.doi.org/10.3390/jof9020230.
Testo completoAbstract (sommario):
Colletotrichum gloeosporioides causes citrus anthracnose, which seriously endangers the pre-harvest production and post-harvest storage of citrus due to its devastating effects on fruit quality, shelf life, and profits. However, although some chemical agents have been proven to effectively control this plant disease, little to no efforts have been made to identify effective and safe anti-anthracnose alternatives. Therefore, this study assessed and verified the inhibitory effect of ferric chloride (FeCl3) against C. gloeosporioides. Our findings demonstrated that FeCl3 could effectively inhibit C. gloeosporioides spore germination. After FeCl3 treatment, the germination rate of the spores in the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) groups decreased by 84.04% and 89.0%, respectively. Additionally, FeCl3 could effectively inhibit the pathogenicity of C. gloeosporioides in vivo. Optical microscopy (OM) and scanning electron microscopy (SEM) analyses demonstrated the occurrence of wrinkled and atrophic mycelia. Moreover, FeCl3 induced autophagosome formation in the test pathogen, as confirmed by transmission electron microscopy (TEM) and monodansylcadaverine (MDC) staining. Additionally, a positive correlation was identified between the FeCl3 concentration and the damage rate of the fungal sporophyte cell membrane, as the staining rates of the control (untreated), 1/2 MIC, and MIC FeCl3 treatment groups were 1.87%, 6.52%, and 18.15%, respectively. Furthermore, the ROS content in sporophyte cells increased by 3.6%, 29.27%, and 52.33% in the control, 1/2 MIC, and MIC FeCl3 groups, respectively. Therefore, FeCl3 could reduce the virulence and pathogenicity of C. gloeosporioides. Finally, FeCl3-handled citrus fruit exhibited similar physiological qualities to water-handled fruit. The results show that FeCl3 may prove to be a good substitute for the treatment of citrus anthracnose in the future.
38
Cohen, Yigal, Yariv Ben Naim, Lidan Falach e Avia E. Rubin. "Epidemiology of Basil Downy Mildew". Phytopathology® 107, n. 10 (ottobre 2017): 1149–60. http://dx.doi.org/10.1094/phyto-01-17-0017-fi.
Testo completoAbstract (sommario):
Basil downy mildew (BDM) caused by the oomycete Peronospora belbahrii is a destructive disease of sweet basil (Ocimum basilicum) worldwide. It originated in Uganda in the 1930s and recently spread to Europe, the Middle East, Americas, and the Far East. Seed transmission may be responsible for its quick global spread. The pathogen attacks leaf blades, producing chlorotic lesions with ample dark asexual spores on the lower leaf surface. Oospores may form in the mesophyll of infected leaves. The asexual spores germinate on a wet leaf surface within 2 h and penetrate into the epidermis within 4 h. Spore germination and infection occur at a wide range of temperatures from 5 to 28.5°C. Infection intensity depends on the length of dew period, leaf temperature, and inoculum dose. The duration of latent period (from infection to sporulation) extends from 5 to 10 days, depending on temperature and light regime. The shortest is 5 days at 25°C under continuous light. Sporulation requires high humidity but not free leaf wetness. Sporulation occurs at 10 to 26°C. At the optimum temperature of 18°C, the process of sporulation requires 7.5 h at relative humidity ≥ 85%, with 3 h for sporophores emergence from stomata and 4.5 h for spore formation. Sporophores can emerge under light or darkness, but spore formation occurs in the dark only. Limited data are available on spore dispersal. Spores dispersed from sporulating plants contaminate healthy plants within 2 h of exposure. Settled spores may survive on leaf surface of healthy plants for prolonged periods, depending on temperature. Seed transmission of the disease occurs in Europe, but not in Israel or the United States. P. belbahrii in Israel also attacks species belonging to Rosemarinus, Nepeta, Agastache, Micromeria, and Salvia but not Plectranthus (coleus). A Peronospora species that infects coleus does not infect sweet basil. Control of BDM includes chemical, physical, and genetic means. The fungicide mefenoxam was highly effective in controlling the disease but resistant populations were quickly selected for in Israel and Europe rendering it ineffective. A new compound oxathiapiprolin (OSBP inhibitor) is highly effective. Nocturnal illumination of basil crops controls the disease by preventing sporulation. Daytime solar heating suppressed the disease effectively by reducing spore and mycelium viability. The most effective physical means is fanning. Nocturnal fanning prevents or limits dew deposition on leaf surfaces, and as a result, infection and sporulation diminish and epidemics are prevented. Genetic resistance occurs in wild basil and its transfer to sweet basil is under way.
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Sogn Andersen, Guri, Henning Steen, Hartvig Christie, Stein Fredriksen e Frithjof Emil Moy. "Seasonal Patterns of Sporophyte Growth, Fertility, Fouling, and Mortality ofSaccharina latissimain Skagerrak, Norway: Implications for Forest Recovery". Journal of Marine Biology 2011 (2011): 1–8. http://dx.doi.org/10.1155/2011/690375.
Testo completoAbstract (sommario):
On the Skagerrak coast the kelpSaccharina latissimahas suffered severe stand reductions over the last decade, resulting in loss of important habitats. In the present study, healthy kelp plants were transplanted into four deforested areas and their patterns of growth, reproduction, and survival were monitored through subsequent seasons. Our main objective was to establish whether the kelp plants were able to grow and mature in deforested areas. We observed normal patterns of growth and maturation at all study sites. However, heavy fouling by epiphytes occurred each summer, followed by high kelp mortality. The study shows that the seasonal variations and the life stage timing ofS. latissimamake formation of self-sustainable populations impossible in the present environment. Most noteworthy, we suggest that fouling by epiphytes is involved in the lack of kelp forest recovery in Skagerrak, Norway.
40
Poluyanov, Alexander, e Nikita Strukov. "Features of the ontogenesis of gametophytes of strains (Matteuccia struthiopteris (L.) Tod.) under conditions of different density of sowing of disputes". Diversity of plant world 1 (8) (27 maggio 2021): 5–17. http://dx.doi.org/10.22281/2686-9713-2021-1-5-17.
Testo completoAbstract (sommario):
The article deals with the effect of sowing density of spores on ontogenesis of gametophytes Matteuccia struthi-opteris (L.) Tod. This species is included in the Red Data Book of the Kursk Region (Krasnaia…, 2017). The ability to form viable gametophytes from spores in Matteuccia struthiopteris is often reduced and depends on many factors, including the population density of the seedlings themselves. Among the numerous forms of thalli of gametophytes in M. struthiopteris (filamentous, spatulate, asymmetric, cordate, wide-heart), only wide-heart thalli form an archegonial cushion capable of fertilization and formation of a zygote with further development of sporophyte. Under natural conditions, the presence of young sporophytes is an important factor contributing to the rejuvenation of populations of M. struthiopteris and an increase in their vitality. In the course of the study, it was established how significant the mutual influence of gametophytes is for their development.
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Ginting, Nurmaini, Hanifah Mutia Z. N. Amrul e Ferdinand Susilo. "AN OVERVIEW OF BRYOPHYTES DIVISION". BIOLINK (Jurnal Biologi Lingkungan Industri Kesehatan) 8, n. 1 (13 agosto 2021): 10–20. http://dx.doi.org/10.31289/biolink.v8i1.4294.
Testo completoAbstract (sommario):
Bryophyte is a non-vascular plant, consisting of three classes: mosses, hornworts, and liverworts. The body forms have a thallus, and some have a leaf-like organ. The class division of the Bryophyte division is base on anatomical and morphological traits, such as meristem tissues, stomata, and vascular tissues. M Bryophyte has no vascular tissue, but it has a capillary that has functions like xylem and commonly refers to as hydroid. Mosses and hornworts have stomata on the sporophyte part, while in the liverworts, stomata are not found. Hornworts have a basal meristem that has an unpredictable cleavage. Meristem on the mosses only divides up the formation of sporangial. In the liverworts, the apical meristem does not see. Members of the hornworts consider the most advanced because the meristematic phase is more prolonged, so that it is closer to the characteristics of Tracheophyta group.
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Tanaka, Yasuyuki, Makio Mori, Koichi Ute e Koichi Hatada. "Structure and Biosynthesis Mechanism of Rubber from Fungi". Rubber Chemistry and Technology 63, n. 1 (1 marzo 1990): 1–7. http://dx.doi.org/10.5254/1.3538238.
Testo completoAbstract (sommario):
Abstract The structure of both terminal units and alignment of the isoprene units give conclusive evidence for the initiation and termination mechanisms of rubber formation in fungi. As shown in Figure 4, the polymerization is estimated to start from trans, trans-farnesyl pyrophosphate and proceeds by successive condensation of IPP to form isoprene units in the cis configuration. The termination is presumed to occur by direct esterification of polyisoprenyl pyrophosphate (PIP-PP) or dephosphorylation of PIP-PP followed by esterification with fatty acids. It is remarkable that the hydroxyl terminal group corresponding to the saponification product from the esterified terminal group was observed in the rubber samples by extraction from sporophores of L. volemus after storage for 2–3 days in a refrigerator without the addition of salt. In these samples, unidentified 13C-NMR signals were also detected. These findings suggest that the direct esterification of PIP-PP is more likely as a termination reaction. It also suggests the occurrence of a chemical or biochemical modification of both terminal groups and the main chain during storage. This is the first information on the termination mechanism of controlling the molecular weight of natural rubber.
43
Hiendlmeyer, Rosane, e Aurea Maria Randi. "Potential for Spore Germination, Sporophyte Formation and Growth of Young Sporophytes of Four Fern Species from the Atlantic Forest (Brazil)". American Fern Journal 100, n. 4 (ottobre 2010): 207–18. http://dx.doi.org/10.1640/0002-8444-100.4.207.
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Hafidh, Said, e David Honys. "Reproduction Multitasking: The Male Gametophyte". Annual Review of Plant Biology 72, n. 1 (17 giugno 2021): 581–614. http://dx.doi.org/10.1146/annurev-arplant-080620-021907.
Testo completoAbstract (sommario):
The gametophyte represents the sexual phase in the alternation of generations in plants; the other, nonsexual phase is the sporophyte. Here, we review the evolutionary origins of the male gametophyte among land plants and, in particular, its ontogenesis in flowering plants. The highly reduced male gametophyte of angiosperm plants is a two- or three-celled pollen grain. Its task is the production of two male gametes and their transport to the female gametophyte, the embryo sac, where double fertilization takes place. We describe two phases of pollen ontogenesis—a developmental phase leading to the differentiation of the male germline and the formation of a mature pollen grain and a functional phase representing the pollen tube growth, beginning with the landing of the pollen grain on the stigma and ending with double fertilization. We highlight recent advances in the complex regulatory mechanisms involved, including posttranscriptional regulation and transcript storage, intracellular metabolic signaling, pollen cell wall structure and synthesis, protein secretion, and phased cell–cell communication within the reproductive tissues.
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Hoffman, Georgia L., e Ruth A. Stockey. "Sporophytes, megaspores, and massulae of Azolla stanleyi from the Paleocene Joffre Bridge locality, Alberta". Canadian Journal of Botany 72, n. 3 (1 marzo 1994): 301–8. http://dx.doi.org/10.1139/b94-039.
Testo completoAbstract (sommario):
Several hundred vegetative and fertile specimens of Azolla Lam. have been recovered from the Paleocene Paskapoo Formation at the Joffre Bridge locality (Middle Tiffanian (Ti3) age) near Red Deer, Alberta. The spore complexes closely resemble those of the Paleocene A. stanleyi Jain & Hall, and the vegetative material is referred to that species. The specimens are unusually complete in that the remains of the fragile sporophyte are preserved, commonly with reproductive structures in place. Plants reaching up to 2.25 cm in length consist of alternately branched rhizomes bearing alternate, imbricate, sessile leaves. Leaves are ovate with entire margins, papillate surfaces, and a single midvein. Reproductive structures have been examined using light, scanning, and transmission electron microscopy. This new material is compared with the other Paleocene species for which sporophytes are known and discussed in terms of evolutionary trends for the genus. The specimens suggest that most of the vegetative characteristics of modern Azolla species were established by the middle Paleocene. Key words: Azolla, Salviniaceae, megaspore, massula, ultrastructure, Paleocene.
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G, Thiribhuvanamala, Krishnamoorthy A. S, Kavitha C, Shwet Kamal, Anil Kumar e Sharma V.P. "Strategic Approaches for Outdoor Cultivation of Paddy Straw Mushroom (Volvariella volvacea) as Intercrop Under different Cropping Systems". Madras Agricultural Journal 108, March (2021): 1–6. http://dx.doi.org/10.29321/maj.10.000486.
Testo completoAbstract (sommario):
The present study aimed to selectpotential strainof Volvariella volvacea suitable for outdoor cultivation in different cropping systems like Banana, Maize, Coconut, Coconut+Banana where such suitable microclimate prevails. Among the different strains of V.volvaceatested, the strain Vv-19-06 obtained from Directorate of Mushroom Research, Solan,performed considerably superior with higher bioefficiency of 17.44 and sturdy sporophores at egg stage and storage life of 1.1 days under refrigerated condition.Moreover, the morphogenesis of button stage to matured mushrooms were extended up to 1.8 days and the opened mushroom were retained on the bed for another 1.6 days, which is an added advantage.Cultivation of paddy straw mushroom as intercrop in Banana, Maize, Banana+coconut and Coconut cropping systems proved successful with spawn running completion ranging from 8 to 10.3 days, pinhead formation ranging from 9.3 to 11.6 days and harvestable button/egg stage appeared ranging from 11 to 12.6 days. The bioefficiency was comparatively better in all the cropping systems, which ranged from 19.4 to 20.6 %, with a total cropping cycle of 20.5 to 22 days.The indoor cropping system, which requires additional cost for infrastructure, also recorded bioefficiecy of 21.3 in a cropping cycle of 17 days. In all the cropping systems tested, the B:C ratio worked out to be 1:2.3 to 1:2.5 as in indoor cropping system proving that paddy straw mushroomcould be promoted for the outdoor systemin Maize, Banana, Banana +coconut , Coconut cropping systems as intercrop as it fetches additional income to rice-growing farmers.
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Chaban, Inna A., Alexander A. Gulevich, Elena A. Smirnova e Ekaterina N. Baranova. "Morphological and Ultrastructural Features of Formation of the Skin of Wheat (Triticum aestivum L.) Kernel". Plants 10, n. 11 (21 novembre 2021): 2538. http://dx.doi.org/10.3390/plants10112538.
Testo completoAbstract (sommario):
The integumentary tissues of plant seeds protect the embryo (new sporophyte) forming in them from unfavorable external conditions; therefore, comprehensive knowledge about the structural and functional specificity of seed covers in various plants may be of both theoretical and practical interest. As a result of our study, additional data were obtained on the morphological and ultrastructural features of the formation of a multilayer skin of wheat (Triticum aestivum L.) kernel (caryopsis). The ultrastructure research analysis showed that differentiation of the pericarp and inner integument of the ovule leads to the formation of functionally different layers of the skin of mature wheat grain. Thus, the differentiation of exocarp and endocarp cells is accompanied by a significant thickening of the cell walls, which reliably protect the ovule from adverse external conditions. The cells of the two-layer inner integument of the ovule differentiate into cuticular and phenolic layers, which are critical for protecting daughter tissues from various pathogens. The epidermis of the nucellus turns into a layer of mucilage, which apparently helps to maintain the water balance of the seed. Morphological and ultrastructural data showed that the formation of the kernel’s skin occurs in coordination with the development of the embryo and endosperm up to the full maturity of the kernel. This is evidenced by the structure of the cytoplasm and nucleus, characteristic of metabolically active protoplasts of cells, which is observed in most integumentary layers at the late stages of maturation. This activity can also be confirmed by a significant increase in the thickness of the cell walls in the cells of two layers of the exocarp and in cross cells in comparison with the earlier stages. Based on these results, we came to the conclusion that the cells of a majority in the covering tissues of the wheat kernel during its ontogenesis are transformed into specialized layers of the skin by terminal differentiation.
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Rozefelds, Andrew C., Mary E. Dettmann, H. Trevor Clifford e Debra Lewis. "Macrofossil evidence of early sporophyte stages of a new genus of water fernTecaropteris(Ceratopteridoideae: Pteridaceae) from the Paleogene Redbank Plains Formation, southeast Queensland, Australia". Alcheringa: An Australasian Journal of Palaeontology 40, n. 1 (25 agosto 2015): 1–11. http://dx.doi.org/10.1080/03115518.2015.1069460.
Testo completo
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Darienko, Tatyana, Cecilia Rad-Menéndez, Christine N. Campbell e Thomas Pröschold. "Molecular Phylogeny of Unicellular Marine Coccoid Green Algae Revealed New Insights into the Systematics of the Ulvophyceae (Chlorophyta)". Microorganisms 9, n. 8 (26 luglio 2021): 1586. http://dx.doi.org/10.3390/microorganisms9081586.
Testo completoAbstract (sommario):
Most marine coccoid and sarcinoid green algal species have traditionally been placed within genera dominated by species from freshwater or soil habitats. For example, the genera Chlorocystis and Halochlorococcum contain exclusively marine species; however, their familial and ordinal affinities are unclear. They are characterized by a vegetative cell with lobated or reticulated chloroplast, formation of quadriflagellated zoospores and living epi- or endophytically within benthic macroalgae. They were integrated into the family Chlorochytriaceae which embraces all coccoid green algae with epi- or endophytic life phases. Later, they were excluded from the family of Chlorococcales based on studies of their life histories in culture, and transferred to their newly described order, Chlorocystidales of the Ulvophyceae. Both genera form a “Codiolum”-stage that serves as the unicellular sporophyte in their life cycles. Phylogenetic analyses of SSU and ITS rDNA sequences confirmed that these coccoid taxa belong to the Chlorocystidales, together with the sarcinoid genus Desmochloris. The biflagellated coccoid strains were members of the genus Sykidion, which represented its own order, Sykidiales, among the Ulvophyceae. Considering these results and the usage of the ITS-2/CBC approach revealed three species of Desmochloris, six of Chlorocystis, and three of Sykidion. Three new species and several new combinations were proposed.
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Pires, Nuno D., e Liam Dolan. "Morphological evolution in land plants: new designs with old genes". Philosophical Transactions of the Royal Society B: Biological Sciences 367, n. 1588 (19 febbraio 2012): 508–18. http://dx.doi.org/10.1098/rstb.2011.0252.
Testo completoAbstract (sommario):
The colonization and radiation of multicellular plants on land that started over 470 Ma was one of the defining events in the history of this planet. For the first time, large amounts of primary productivity occurred on the continental surface, paving the way for the evolution of complex terrestrial ecosystems and altering global biogeochemical cycles; increased weathering of continental silicates and organic carbon burial resulted in a 90 per cent reduction in atmospheric carbon dioxide levels. The evolution of plants on land was itself characterized by a series of radical transformations of their body plans that included the formation of three-dimensional tissues, de novo evolution of a multicellular diploid sporophyte generation, evolution of multicellular meristems, and the development of specialized tissues and organ systems such as vasculature, roots, leaves, seeds and flowers. In this review, we discuss the evolution of the genes and developmental mechanisms that drove the explosion of plant morphologies on land. Recent studies indicate that many of the gene families which control development in extant plants were already present in the earliest land plants. This suggests that the evolution of novel morphologies was to a large degree driven by the reassembly and reuse of pre-existing genetic mechanisms.