Serotiny in Melocactus matanzanus (Cactaceae) and role of cephalium in dispersal of seeds after the individual's death

Seed Science Research ◽

10.1017/s0960258521000283 ◽

2021 ◽

pp. 1-7

Author(s):

Duniel Barrios ◽

Sandy Toledo ◽

Jorge A. Sánchez ◽

Luis R. González-Torres

Keyword(s):

Environmental Variability ◽

Different Ages ◽

Growth Chambers ◽

Viable Seeds ◽

Mature Seeds

Abstract Serotiny is a strategy in which the retention of mature seeds in parent structures allows plants to cope with environmental variability like heat, drought or fire. Although this phenomenon might be common in Cactaceae, and particularly in Melocactus, it has generally been scarcely addressed. The main goal of our work is to investigate if there are seeds hidden in the cephalium of Melocactus matanzanus and if there are, determine whether or not these seeds maintain their viability. We also discuss some advantages the cephalium may offer as diaspore after the death of individuals. Cephalia collected from dead individuals were divided into four slices and their seeds counted; we also assessed the viability and photoblastic response of the seeds by using growth chambers at 25/30°C, and by a cut test on the seeds that did not germinate. Our results showed retention of viable seeds of different ages in all slices of the cephalium. Seeds were photoblastic positive with germination between 11–22% and viability above 50% in the portion of the lots that did not germinate.

Download Full-text

The Role of Solid Springer in Masonry Vault

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.133-134.349 ◽

2010 ◽

Vol 133-134 ◽

pp. 349-354 ◽

Cited By ~ 1

Author(s):

Vittorio Ceradini ◽

Michele Candela ◽

Roberta Fonti

Keyword(s):

Scientific Research ◽

Evolution Process ◽

Limit Case ◽

Structural Configuration ◽

Structural Role ◽

Different Ages ◽

Building Component ◽

And Function ◽

Technical Rules

During a scientific research, directed to understand the structural role of some particular masonry elements, noticeable in covering structures like vault and dome, we searched the technical rules and function of these elements. We verified that in literature there is no specific documentation about these elements and its mechanic purposes. The study was directed to recognize the most representatives architectures in different ages, and to identify the construction technique’s evolution process of this particular arc-double or thickening of arc that we arrived to identify as a necessary building component to give balance in particular structural configuration. This process put down roots from the roman ancient age, until baroque age, where the most original applications of this regulation were placed. From Pantheon to the limit case of St. Filippo Neri chapel, the covers’ structures springer angle studied was analyzed together with its relation to plan, sections and elevation of all buildings. Therefore, if these elements are well-performed, they follow precise constructive patterns that this article would like to identify and show.

Download Full-text

Monitoring studies should consider temporal variability to reveal relations between cyanobacterial abundance and environmental variables

Anais da Academia Brasileira de Ciências ◽

10.1590/0001-3765201520140416 ◽

2015 ◽

Vol 87 (3) ◽

pp. 1717-1726 ◽

Cited By ~ 3

Author(s):

JULIANA WOJCIECHOWSKI ◽

ANDRÉ A. PADIAL

Keyword(s):

Temporal Variability ◽

Environmental Variables ◽

Environmental Changes ◽

Environmental Variability ◽

Time Lag ◽

Cyanobacteria Blooms ◽

Environment Variables ◽

Sampling Points ◽

The Relationship

One of the main goals of monitoring cyanobacteria blooms in aquatic environments is to reveal the relationship between cyanobacterial abundance and environmental variables. Studies typically correlate data that were simultaneously sampled. However, samplings occur sparsely over time and may not reveal the short-term responses of cyanobacterial abundance to environmental changes. In this study, we tested the hypothesis that stronger cyanobacteria x environment relationships in monitoring are found when the temporal variability of sampling points is incorporated in the statistical analyses. To this end, we investigated relationships between cyanobacteria and seven environmental variables that were sampled twice yearly for three years across 11 reservoirs, and data from an intensive monitoring in one of these reservoirs. Poor correlations were obtained when correlating data simultaneously sampled. In fact, the 'highly recurrent' role of phosphorus in cyanobacteria blooms is not properly observed in all sampling periods. On the other hand, the strongest correlation values for the total phosphorus x cyanobacteria relationship were observed when we used the variation of sampling points. We have also shown that environment variables better explain cyanobacteria when a time lag is considered. We conclude that, in cyanobacteria monitoring, the best approach to reveal determinants of cyanobacteria blooms is to consider environmental variability.

Download Full-text

Seedling emergence of Betula maximowicziana following human disturbance and the role of buried viable seeds

Forest Ecology and Management ◽

10.1016/s0378-1127(96)03963-1 ◽

1997 ◽

Vol 93 (3) ◽

pp. 235-243 ◽

Cited By ~ 31

Author(s):

Katsuhiro Osumi ◽

Shobu Sakurai

Keyword(s):

Human Disturbance ◽

Seedling Emergence ◽

Betula Maximowicziana ◽

Viable Seeds

Download Full-text

Sheep gut passage and survival of Mediterranean shrub seeds

Seed Science Research ◽

10.1079/ssr2004192 ◽

2005 ◽

Vol 15 (1) ◽

pp. 21-28 ◽

Cited By ~ 45

Author(s):

Pablo Manzano ◽

Juan E. Malo ◽

Begoña Peco

Keyword(s):

Potential Role ◽

Central Spain ◽

Long Distance ◽

Retama Sphaerocarpa ◽

Gut Passage ◽

Lavandula Stoechas ◽

Significant Difference ◽

Ecological Importance ◽

Viable Seeds

Although viable seeds of Mediterranean dry-fruited shrubs are found in herbivore dung, the ecological importance of this observation is still not well understood. We analysed seed retrieval percentages, defecation time and germinability after sheep gut passage for the five most common shrub species of an area in central Spain (Retama sphaerocarpa, Cytisus scoparius, Halimium umbellatum subsp. viscosum, Cistus ladanifer and Lavandula stoechas subsp. pedunculata). Five ewes were fed seeds, and their dung was collected regularly during the following week. Seeds were hand-sorted from dung subsamples and tested for germinability. The defecated seeds were clustered in time, with a majority retrieved in the 24–40 h period, although over 1% of the seeds were retained in the gut for more than 72 h. Data suggested a possible link between seed size and retrieval, with medium-sized seeds less damaged (16–23%) than larger and smaller seeds (10–12%), although only a small number of species were studied. Germination results showed an increased percentage of germination after gut passage for H. umbellatum (x2 test, P<0.05) and a marginally significant difference for C. scoparius (P<0.1). Soft-seeded L. stoechas did not germinate after gut passage. The results indicate a potential role of herbivore endozoochory for the long-distance dispersal of dry-fruited shrubs and their potential colonization of distant sites.

Download Full-text

Seed and Seedling Biology of the Woody-fruited Proteaceae

Australian Journal of Botany ◽

10.1071/bt96135 ◽

1998 ◽

Vol 46 (4) ◽

pp. 387 ◽

Cited By ~ 35

Author(s):

Philip K. Groom ◽

Byron B. Lamont

Keyword(s):

Drought Stress ◽

Seedling Establishment ◽

Comparative Biology ◽

Wet Season ◽

Successful Establishment ◽

Drought Resistant ◽

Viable Seeds ◽

In Fire ◽

Great Scope

Within the Proteaceae, 353 species confined to 7 genera in the Grevilleoideae have woody fruits. The majority (> 70%) occur in fire-prone vegetation on nutrient-poor, summer-dry soils of south-western Australia. These species are characterised by large, winged seeds contained within serotinous follicles. Seed release is mediated by desiccation of the follicle walls resulting from fruit death, although wet–dry cycles are required in some genera. After release, germination must take place by the next wet season, as the seeds are not long-lived. Seeds are particularly high in protein (40–60%), P (1–2%) and Fe (10–60‰) compared with other Proteaceae. Seeds are favoured food for pre- and post-dispersal granivores (insects, birds, rodents) and young seedlings are favoured by herbivores (insects, marsupials), with the more serotinous fruits providing extra protection for their seeds. Successful establishment is facilitated by the protective and water retentive role of the testa during germination, and the remobilisation of N and P from the cotyledons to the seedling within 10 weeks of emergence. Drought stress reduces seedling establishment in otherwise favourable postfire microsites and prevents it (assisted by herbivores) in mature vegetation. Typically, < 10% of seeds released after fire become seedlings, and < 50% of these survive the first summer. Among fire-killed species, species that produce few seeds are more likely to have drought-resistant seedlings, often associated with larger seeds and/or needle-shaped leaves. Species that resprout after fire produce a few large viable seeds per plant, whereas fire-killed species produce many smaller seeds. Of all the Proteaceae, the ecology of woody-fruited species is best known, providing great scope for comparative biology studies.

Download Full-text

Auxin: Hormonal Signal Required for Seed Development and Dormancy

Plants ◽

10.3390/plants9060705 ◽

2020 ◽

Vol 9 (6) ◽

pp. 705 ◽

Cited By ~ 2

Author(s):

Angel J. Matilla

Keyword(s):

Seed Development ◽

Higher Plants ◽

Aba Signaling ◽

Seed Formation ◽

Cellular Processes ◽

Primary Dormancy ◽

Cellular Machinery ◽

Hormonal Signal ◽

Viable Seeds

The production of viable seeds is a key event in the life cycle of higher plants. Historically, abscisic acid (ABA) and gibberellin (GAs) were considered the main hormones that regulate seed formation. However, auxin has recently emerged as an essential player that modulates, in conjunction with ABA, different cellular processes involved in seed development as well as the induction, regulation and maintenance of primary dormancy (PD). This review examines and discusses the key role of auxin as a signaling molecule that coordinates seed life. The cellular machinery involved in the synthesis and transport of auxin, as well as their cellular and tissue compartmentalization, is crucial for the development of the endosperm and seed-coat. Thus, auxin is an essential compound involved in integuments development, and its transport from endosperm is regulated by AGAMOUS-LIKE62 (AGL62) whose transcript is specifically expressed in the endosperm. In addition, recent biochemical and genetic evidence supports the involvement of auxins in PD. In this process, the participation of the transcriptional regulator ABA INSENSITIVE3 (ABI3) is critical, revealing a cross-talk between auxin and ABA signaling. Future experimental aimed at advancing knowledge of the role of auxins in seed development and PD are also discussed.

Download Full-text

The Role of FNAC in Diagnosis of Breast Disease at Different Ages - 208 Cases

Journal of Bangladesh College of Physicians and Surgeons ◽

10.3329/jbcps.v30i3.12462 ◽

2012 ◽

Vol 30 (3) ◽

pp. 137-140 ◽

Cited By ~ 1

Author(s):

S M Shafiul Azam Chaudhury ◽

Md Khurshid Alam ◽

Md Serajul Haque

Keyword(s):

Fine Needle Aspiration ◽

Fine Needle Aspiration Cytology ◽

Breast Disease ◽

Needle Aspiration ◽

Common Disease ◽

Aspiration Cytology ◽

Fine Needle ◽

Different Ages ◽

Needle Aspiration Cytology

All breast lesions are not malignant, and all the benign lesions do not progress to cancer; however the accuracy of diagnosis can be increased by a combination of preoperative tests. About 30% of women suffer from breast disease in their lifetime. The main objectives are to explore the role of FNAC in diagnosis of breast disease at different ages. Fine needle aspiration cytology (FNAC) has become a critical component in the investigation of palpable breast masses. Total 208 cases included in this study at Comilla. The data was formulated and analyzed by SPSS-12. 79(37.98%) cases were at the age of 21-30 years and next one was 11-20 years which was 48(23.07%). Among them 40(19.23%) cases were malignant and 168(80.77%) cases were benign in nature. The incidence of malignancy was increased with relation to age. As the age is more chance of malignancy is more. In benign types fibroadenoma was the common disease then the duct cell carcinoma, fibrocystic change, suppurative inflammation respectively. The findings were 43.75%, 19.23%, 18.27% and 8.65%.In conclusion, fine needle aspiration cytology, for diagnosis of breast lump can reduce the number of open biopsy and surgery. DOI: http://dx.doi.org/10.3329/jbcps.v30i3.12462 J Bangladesh Coll Phys Surg 2012; 30: 137-140

Download Full-text

The Development and Mobilisation of Seed Reserves in Some African Orchids

Australian Journal of Botany ◽

10.1071/bt9870343 ◽

1987 ◽

Vol 35 (3) ◽

pp. 343 ◽

Cited By ~ 38

Author(s):

JC Manning ◽

Staden J Van

Keyword(s):

Chromatographic Analysis ◽

External Source ◽

Free Sugars ◽

Gas Chromatographic Analysis ◽

Immature Seeds ◽

Seed Reserves ◽

Endogenous Reserves ◽

Mature Seeds

The development, final appearance and digestion (during germination) of seed reserves in a number of genera of the Orchidaceae (tribe Orchideae) has been studied comprehensively, using ultrastructural and histochemical techniques complemented by gas chromatographic analysis of free sugars. Mature seeds of Disa, Disperis and Huttonaea contain substantial reserves of lipid and protein in the embryo. The protodermal cells of Disperis also contain protein-carbohydrate bodies. Free sugars are present but starch occurs only in immature seeds. Glyoxysomes are absent and lipolysis does not occur in seeds incubated without an external source of sucrose, and although a little starch is formed it is apparently synthesised from endogenous sucrose reserves. In the presence of exogenous sucrose, however, proteins are hydrolysed and glyoxysomes appear. Substantial quantities of starch are formed in such seeds. From these observations it is apparent that orchid seeds are unable to utilise endogenous reserves of lipid unless simple sugars are supplied to the medium but can utilise the free sugars present in the embryo. Resultant conclusions on the role of mycorrhizae in the germination of orchid seeds are discussed.

Download Full-text