scholarly journals Taxonomy and reproductive biology of the genus Zephyranthes Herb. (Liliaceae) in Bangladesh

2018 ◽  
Vol 25 (1) ◽  
pp. 57-69 ◽  
Author(s):  
Sumona Afroz ◽  
M. Oliur Rahman ◽  
Md. Abul Hassan

The genus Zephyranthes Herb. is revised along with its pollination mechanism, seed germination and vegetative propagation. Detailed taxonomy of four Zephyranthes species occurring in Bangladesh, namely, Z. atamasco (L.) Herb., Z. candida (Lindl.) Herb., Z. carinata Herb. and Z. tubispatha (L’Her.) Herb. ex Traub. was studied with their updated nomenclature, important synonyms, phenology, specimens examined, habitat, distribution, economic value and mode of propagation. A dichotomous bracketed key is provided for easy identification of the species. Pollination investigation reveals that all studied species of Zephyranthes are self-pollinated. Minimum five days were required for germination of seeds in Z. atamasco, and three days each in Z. candida, Z. carinata and Z. tubispatha. Pseudovivipary type of germination has been reported in Z. candida and Z. carinata for the first time. The maximum number of seeds (30) per fruit are produced in Z. tubispatha, whereas the minimum seeds (2) per fruit are found in Z. atamasco. Vegetative propagation through bulb was found more suitable than seeds in Z. atamasco, Z. candida and Z. carinata. Pollen viability has been found 100% in Z. candida, and Z. tubispatha, whereas, Z. atamasco and Z. carinata have shown 80% and 98% viability, respectively. Bangladesh J. Plant Taxon. 25(1): 57-69, 2018 (June)

1970 ◽  
Vol 17 (1) ◽  
pp. 69-78
Author(s):  
Shamim Ara Liza ◽  
Md. Oliur Rahman ◽  
Md. Zashim Uddin ◽  
Md. Abul Hassan ◽  
Momtaz Begum

This paper presents the flower morphology, pollination mechanisms and seed germination of three indigenous medicinal plants of Bangladesh namely, Asclepias curassavica L., Clerodendrum viscosum Vent. and Scoparia dulcis L. The minimum days taken for seed germination in Asclepias curassavica, Clerodendrum viscosum and Scoparia dulcis are 6, 14 and 9, respectively. Epigeal type of seed germination has been noted in Asclepias curassavica and Scoparia dulcis, whereas hypogeal type of seed germination has been found in Clerodendrum viscosum. Fruit production is highest in Scoparia dulcis among the species studied and a maximum of 304 seeds are produced per fruit in it. Maximum 108 seeds are produced per fruit in Asclepias curassavica. Among the species investigated Asclepias curassavica and Clerodendrum viscosum are cross-pollinated, and Scoparia dulcis is self-pollinated. Butterflies, bees and ants are noted to be the pollinators in Asclepias curassavica and in Clerodendrum viscosum black ants, butterflies and long tongue hawk moths are the pollinators.Keywords: Taxonomy; pollination; seed germination; Asclepias curassavica L.; Clerodendrum viscosum Vent.; Scoparia dulcis L.DOI: 10.3329/bjpt.v17i1.5391Bangladesh J. Plant Taxon. 17(1): 69-78, 2010 (June)


Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 186
Author(s):  
Luana Bontempo ◽  
Daniela Bertoldi ◽  
Pietro Franceschi ◽  
Fabio Rossi ◽  
Roberto Larcher

Umbrian tobacco of the Virginia Bright variety is one of the most appreciated tobaccos in Europe, and one characterized by an excellent yield. In recent years, the Umbria region and local producers have invested in introducing novel practices (for production and processing) focused on environmental, social, and economic sustainability. Due to this, tobacco from Umbria is a leading commodity in the global tobacco industry, and it claims a high economic value. The aim of this study is then to assess if elemental and isotopic compositions can be used to protect the quality and geographical traceability of this particular tobacco. For the first time the characteristic value ranges of the stable isotope ratios of the bio-elements as a whole (δ2H, δ13C, δ15N, δ18O, and δ34S) and of the concentration of 56 macro- and micro-elements are now available, determined in Virginia Bright tobacco produced in two different areas of Italy (Umbria and Veneto), and from other worldwide geographical regions. The ranges of variability of elements and stable isotope ratios had slightly different results, according to the three geographical origins considered. In particular, Umbria samples presented significantly lower content of metals potentially dangerous for human health. The results of this first exploratory work highlight the possibility of characterizing tobacco from Umbria, and suggest widening the scope of the survey throughout Italy and foreign regions, in order to be used to describe the geographical origin of tobacco in general and verify the origin of the products on the market.


Reproduction ◽  
2009 ◽  
Vol 138 (6) ◽  
pp. 979-986 ◽  
Author(s):  
Hemin Zhang ◽  
Desheng Li ◽  
Chendong Wang ◽  
Vanessa Hull

Successful conservation of an endangered species relies on a good understanding of its reproductive biology, but there are large knowledge gaps. For example, many questions remain unanswered with regard to gestation and fetal development in the giant panda. We take advantage of a sample size that is unprecedented for this species (n=13) to explore patterns in reproductive development across individuals at the China Conservation and Research Center for the Giant Panda. We use ultrasound techniques on multiple giant pandas for the first time to empirically confirm what has long been suspected that pandas exhibit delayed implantation of the embryo. We also show that the duration of postfetal detection period is remarkably similar across individuals (16.85±1.34 days). Detection of fetus by ultrasound was strongly correlated to the peak in urinary progesterone (r=0.96, t=8.48, d.f.=8, P=0.0001) and swelling in the mammary glands (r=0.79, t=3.61, d.f.=8, P=0.007) and vulva (r=0.91, t=6.40, d.f.=8, P=0.0002) of adult females. When controlling for both the duration of the total gestation period and the postfetal detection period, infant birth weight was only significantly predicted by the latter (β=11.25, s.e.m.=4.98, t=2.26, P=0.05), suggesting that delayed implantation increases flexibility in the timing of birth but is not important in dictating infant growth. This study informs reproductive biology by exploring the little-studied phenomenon of delayed implantation in relationship to physiological changes in pregnant giant panda females.


2016 ◽  
Vol 76 (4) ◽  
pp. 975-982 ◽  
Author(s):  
N. A. S. Nunes ◽  
A. V. Leite ◽  
C. C. Castro

Abstract Phenology and reproductive biology of cultivated species are important for the comprehension of the requirements for fruit and seed production and the management of pollinators. This study aimed to characterise the phenology, reproductive biology and growing degree days of the grapevine ‘Isabel’ (Vitis labrusca) in northeastern Brazil during January 2011 (P1), Augst 2011 (P2), April 2012 (P3) and August 2012 (P4). We recorded the duration (days) of the phenological stages, pruning (P), woolly bud (W), budburst (B), inflorescence development (ID), flowering (F), ripening (R) and harvest (H). We analysed the floral biology, the sexual system and the breeding system. We measured the growing degree days (GDD) required to reach the subperiods P-B, B-F and F-H. The periods P1, P2, P3 and P4 lasted for 116, 125, 117 and 130 days, respectively. The number of days of harvest were similar in the same dry (P1 and P3) and rainy (P2 and P4) periods. All the periods that we recorded were shorter than those observed in other regions of Brazil, which may be attributable to the mean temperature and carbohydrate metabolism. The flowers are green, hermaphroditic, with an odour of mignonette, low pollen viability and autogamous. The base temperature of 10°C was considered the most adequate for the subperiods as has been documented for other grape varieties in Brazil. Thus, temperature was also the most adequate for the cycles, presenting a smaller standard deviation (0.119, 0.147, 0.156 and 0.153 to P1, P2, P3 and P4, respectively) when compared to a base temperature of 12°C (0.122, 0.158, 0.165 and 0.160 to P1, P2, P3 and P4, respectively). The higher and the lower observed GDD were 1972.17 and 1870.05, respectively, both above the values recorded in other parts of Brazil for same variety. The phonological results, including knowledge of growing degree days, are important to the planning of cultures at the study site and in other regions that have similar climatic conditions and make it possible to pre-determine the harvest.


2021 ◽  
Vol 38 ◽  
pp. 00046
Author(s):  
Margarita Ishmuratova ◽  
Saltanat Tleukenova ◽  
Alibek Ramasanov ◽  
Elena Gavrilkova ◽  
Dmitrii Ageev

For the first time, the depending of germination rate and energy of germination of Chartolepis intermedia seeds, collected in the wild of Karaganda region, from morphology of seeds and conditions of cryopreservation is investigated. The maximum results for viability are fixed for dark-colored average or large seeds. The best results are determined for variant of cryopreservation in plastic container with future defrosting at the room temperature. For the increasing parameters of seed germination we recommended to freeze Chartolepis intermedia seeds with using cryoprotector sucrose in concentration 20%. As the results of the study, we developed algorithm of cryopreservation of Chartolepis intermedia seeds in liquid nitrogen.


2019 ◽  
Vol 17 (3) ◽  
pp. 237-256
Author(s):  
Eldrin De Los Reyes ARGUELLES

In spite of the fact that epiphytic algae are considered an important component of freshwater ecosystems, our knowledge of their diversity and distribution is still rather poor. Taxonomic study on the composition of epiphytic algae living on submerged leaf and root tissues of macrophyte Nymphaea pubescens Willd, found at Laguna de Bay (Philippines), was conducted. In total, 21 algal taxa were identified: 10 Cyanophyceae, 6 Trebouxiophyceae, and 5 Bacillariophyceae. The taxa described in this study represent 13 orders, 16 families, 18 genera, and 21 species based on the recent combined taxonomical approach. Of these taxa, the occurrence of a rare cyanobacteria, Chroococcus schizodermaticus West, is reported for the first time in the Philippines. One species is also reported here for the first time in the Philippines, based on current taxonomic nomenclature, and this is Cyanothece aeruginosa (Nägeli) Komárek, which is based on the former name of Synechococcus aeruginosus Nägeli. These taxonomic records are considered important basal information in enriching the knowledge about the diversity and habitat distribution of cyanobacteria and microalgae in macrophytes found in freshwater habitats in the Philippines.


1993 ◽  
Vol 41 (5) ◽  
pp. 527 ◽  
Author(s):  
SP Obrien ◽  
DM Calder

The reproductive biology and floral phenologies of co-occurring Leptospermum myrsinoides and L. continentale were investigated. Both species have similar floral structure and both are protandrous. Anther dehiscence is staggered over approximately 6 days and pollen viability remains high for at least 3 days. The styles of both species are short at anthesis but extend during the next 6 days to approximately the same height as the anthers. The stigmas of these species do not achieve maximum receptivity until at least 4 days after anthesis. Both species are self-compatible. At the three sites studied, L. myrsinoides and L. continentale have separate flowering times with L. myrsinoides always flowering first. Within populations of each species, plants reached first flower and peak flower in the same order in 1989 and 1990, implying genetic control over flowering time. It is suggested that protandry in these species enhances the likelihood of outcrossing and the staggered release of pollen coupled with the degree of overlap within flowering populations increases the number of potential mates available to each flower.


2020 ◽  
Vol 142 (2) ◽  
pp. 755-763
Author(s):  
Iwona Stawoska ◽  
Aleksandra M. Staszak ◽  
Iwona Ciereszko ◽  
Jakub Oliwa ◽  
Andrzej Skoczowski

Abstract Thermoanalytical methods are widely used to study seed germination processes. Our research aimed to use them in order to monitor the germination of maize seeds. To this end, we employed—for the first time—the isothermal calorimetric method with full oxygen access. Dry seeds were placed in ampoules with threaded caps, filled with distilled water. Heat flow was recorded in microwatts at 20 °C for 72 h in order to determine changes in thermal power associated with germination. In parallel with these measurements, in the same time regime, we measured FT-Raman spectra, which allowed us to analyze how endosperm and embryo changed their chemical compositions during imbibition and germination. Spectra obtained for endosperm reflected chemical changes resulting from catabolic processes. We also analyzed variations in the secondary structure of proteins in the embryo accompanying germination. Decomposition of amide I bands proved that during germination and protein hydrolysis, the content of helical and β-sheet structures decreased. Furthermore, in the embryos of dry seeds, S-S linkages were in both gauche–gauche-trans and trans-gauche-trans conformations, but after imbibition, only gauche–gauche-trans conformation can be identified.


2019 ◽  
Vol 170 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Donell Holloway

This article discusses the positioning of children both as objects of economic activity as and subjects of market relations under surveillance capitalism. It looks briefly at the history of children’s engagement with the market economy from their engagement in the labour force during industrial revolution times; their disappearance from direct economic activity during the Romantic Movement; through to their emergence as both data sources and data consumers within a big data economy. It argues that this is the first time since children retreated from the paid labour force in the late 19th and early 20th centuries due to labour law reforms that their activities are of significant economic value, and that the emergence of Internet-connected toys and things for children will significantly amplify children’s position as data sources under surveillance capitalism.


2010 ◽  
Vol 31 (4) ◽  
pp. 463-473 ◽  
Author(s):  
Roberta Richard Pinto ◽  
Otavio Augusto Vuolo Marques ◽  
Ronaldo Fernandes

AbstractThe reproductive biology of Chironius flavolineatus and C. quadricarinatus from the Brazilian Cerrado domain is described, including sexual maturity, female fecundity, and reproductive cycles of males and females. Egg-laying is recorded here for the first time for C. quadricarinatus. Males of both species attain sexual maturity with a smaller snout-vent length than females. Females of C. flavolineatus have an extended reproductive cycle with egg production during the wet season, whereas males exhibit year-round sperm production. Chironius quadricarinatus has continuous reproductive cycles in both sexes. Differences in reproductive pattern between these two sympatric species are probably related to phylogenetic constraints on intrageneric lineages of Chironius.


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