scholarly journals The role of ultraviolet reflectance and pattern in the pollination system of Hypoxis camerooniana (Hypoxidaceae)

AoB Plants ◽  
2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Yannick Klomberg ◽  
Raissa Dywou Kouede ◽  
Michael Bartoš ◽  
Jan E J Mertens ◽  
Robert Tropek ◽  
...  
Keyword(s):  
Plant Species ◽  
Central Africa ◽  
Complete Removal ◽  
Reproductive Organs ◽  
Specific Pattern ◽  
Flowering Plant ◽  
Pollination System ◽  
Mount Cameroon ◽  
Uv Reflectance ◽  
Montane Grasslands

Abstract Apart from floral morphology and colours perceived by the human eye, ultraviolet (UV) reflectance acts as an important visual advertisement of numerous flowering plant species for pollinators. However, the effect of UV signalling on attracting pollinators of particular plant species is still insufficiently studied, especially in the Afrotropics. Therefore, we studied the pollination system of Hypoxis camerooniana in montane grasslands of Mount Cameroon, West/Central Africa. We focused mainly on the effects of the flowers’ UV reflectance on its visitors. We experimentally removed UV reflection from petals either completely or partially. Thereafter, flower visitors were recorded and pistils were collected post-flowering to quantify germinated pollen tubes per treatments. The most important visitors were bees, followed by flies. Due to their contacts with reproductive organs bees are considered as the primary pollinators. Visitation rates were lower when UV reflectance was completely removed, whereas the decrease of frequency on half-treated flowers did not differ significantly from control treatments. The complete removal of UV also affected bees’ landing behaviour, but not that of flies. We showed that the presence of UV reflectance is more important than UV pattern for bees visiting flowers of H. camerooniana. We hypothesize that exploiting all flowers irrespective of their pattern can be more efficient for pollinators in the open grasslands of high altitudes to spot these relatively scarce flowers by their UV reflectance. Furthermore, we highlight the necessity of both experimental and natural controls in similar studies to control for additional effects of the used UV manipulations. Many plants advertise their flowers with UV reflectance visible to their insect visitors. By manipulating the UV reflectance and pattern of Hypoxis camerooniana in the Afromontane grasslands of Mount Cameroon, we have shown how crucial it is for the predominant visitor, bees. Both bees' preferences for flowers and their behaviour during visits are influenced by changes in UV reflectance. However, the presence of some UV signal is more important than the specific pattern. Especially in montane grasslands with higher UV irradiation, the UV floral colours are important for recognition of flowers by potential pollinators.

scholarly journals Notes on the threatened lowland forests of Mt Cameroon and their endemics including Drypetes burnleyae sp. nov., with a key to species of Drypetes sect. Stipulares (Putranjivaceae)

Kew Bulletin ◽  
2021 ◽  
Author(s):  
Martin Cheek ◽  
Nouhou Ndam ◽  
Andrew Budden
Keyword(s):  
Conservation Management ◽  
Conservation Status ◽  
Central Africa ◽  
Habitat Destruction ◽  
Coastal Forests ◽  
Key To Species ◽  
International Union ◽  
Species Discovery ◽  
Mount Cameroon ◽  
Lowland Forests

SummaryThis paper reports a further discovery of a new endemic threatened species to science in the context of botanical surveys in the lowland coastal forests of Mount Cameroon in the Cross River-Sanaga interval of west-central Africa. These studies now focus on species discovery and conservation through the Tropical Important Plant Areas programme. New species to science continue to be discovered from Mt Cameroon. Most of these species are rare, highly localised, and threatened by habitat destruction, increasing the justification for improved conservation management of surviving habitat. Drypetes burnleyae is placed in and keyed out in Drypetes sect. Stipulares, a group mostly confined to Lower Guinea, here adjusted to accommodate nine species. The conservation status of Drypetes burnleyae is assessed as Endangered (EN B1+2ab(iii)) according to the 2012 criteria of the International Union for the Conservation of Nature. An updated overview of the plant endemics of Mt Cameroon is presented.

Petrography and geochemistry of sulfurous volcanic scoria from mount Cameroon area, Central Africa: Implications for Au-PGE exploration

2021 ◽  
Vol 176 ◽  
pp. 104144
Author(s):  
Elisé Sababa ◽  
Fuh Calistus Gentry ◽  
Paul-Désiré Ndjigui ◽  
Pierre Noah Onana ◽  
Djimet Tetedjima Seyoa
Keyword(s):  
Central Africa ◽  
Mount Cameroon

scholarly journals Epimutations are associated with CHROMOMETHYLASE 3-induced de novo DNA methylation

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Jered M Wendte ◽  
Yinwen Zhang ◽  
Lexiang Ji ◽  
Xiuling Shi ◽  
Rashmi R Hazarika ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Plant Species ◽  
Dna Methyltransferase ◽  
Constitutive Heterochromatin ◽  
De Novo ◽  
Flowering Plant ◽  
Gene Body ◽  
Gene Body Methylation ◽  
Mechanistic Basis ◽  
Flowering Plant Species

In many plant species, a subset of transcribed genes are characterized by strictly CG-context DNA methylation, referred to as gene body methylation (gbM). The mechanisms that establish gbM are unclear, yet flowering plant species naturally without gbM lack the DNA methyltransferase, CMT3, which maintains CHG (H = A, C, or T) and not CG methylation at constitutive heterochromatin. Here, we identify the mechanistic basis for gbM establishment by expressing CMT3 in a species naturally lacking CMT3. CMT3 expression reconstituted gbM through a progression of de novo CHG methylation on expressed genes, followed by the accumulation of CG methylation that could be inherited even following loss of the CMT3 transgene. Thus, gbM likely originates from the simultaneous targeting of loci by pathways that promote euchromatin and heterochromatin, which primes genes for the formation of stably inherited epimutations in the form of CG DNA methylation.

scholarly journals On the effects of castration and ovariotomy upon sheep

1912 ◽  
Vol 85 (576) ◽  
pp. 27-32 ◽  
Keyword(s):  
Old Age ◽  
Early Life ◽  
Complete Removal ◽  
Reproductive Organs ◽  
Fallow Deer ◽  
The Body ◽  
Male Characters ◽  
Game Birds ◽  
Male Plumage ◽  
The Face

It is well known that castration, when performed in early life and before sexual maturity has been reached, has a marked effect not only in inhibiting the development of the accessory male organs, but in changing the general conformation of the body. Thus in castrated guinea-pigs, oxen, and capons, as well as in eunuchs, the bones of the limbs tend to be abnormally long, this result depending upon an arrest in the ossification of epiphyses. The secondary male characters are also in many cases suppressed, so that there is an apparent approximation to the female type. Thus in red deer if the testes are removed in quite immature animals the antlers fail to make their appearance, and in fallow deer castration at birth limits the horn formation to the development of single dugs. Secondary sexual characters, however, are not always correlated with the presence of the essential reproductive organs, even in mammals. Thus the withers in the gelding resemble those of the horse rather than those of the mare, in which the witheres are lower. Moreover, in certain varieties of cattle in Italy, the horns in the ox, if castraction has been carried out young, are far longer than those of either the bull or the cow. Ovariotomy in the female is often said to lead to the assumption of male characters, but there is little experimental evidence that this is actually the case. In the human female complete removal of the ovaries, if carried out in early life, besides preventing the onset of puberty and the occurrence of menstruation, produces effects on the general form and appearance, individuals so operated upon being said, in some cases, to show resemblances to men. Abnormalities in the ovaries have been described as producing similar results. Thus, Rörig records three cases in which female deer possessed horns, and were shown on dissection to have had abnormal ovaries. Darwin states that female deer in old age have been known to acquire horns. It Wallace says that in old mares the neck tends to acquire an arch as in the stallion. The occasional growth of hair on the face in old women is a phenomenon of the same kind. Similar observations have been made upon birds, especially ducks, poultry, and game birds. Darwin mentions the case of a duck which, when 10 years old, acquired the plumage of the drake. Other cases are those of hens which in old age assumed secondary male characters and started to crow. Hunter mentions a hen pheasant which had male plumage associated with an abnormal ovary. Numerous other instances have been described, but it is not apparent that such an acquirement of male characters by female individuals is always correlated with an abnormality in the reproductive organs. According to Gurney the assumption of male plumage is generally associated with sterility in female gallinaceous birds, but not, as a rule, in female passerine birds. Thus Gurney describes a hen chaffinch with male plumage and a number of developing eggs.

scholarly journals Toevoegings tot die blomplantlys van die Bergkwagga Nasionale Park

Koedoe ◽  
1977 ◽  
Vol 20 (1) ◽  
Author(s):  
B.L. Penzhorn
Keyword(s):  
Plant Species ◽  
National Park ◽  
Flowering Plants ◽  
Flowering Plant ◽  
Check List ◽  
Flowering Plant Species

Additions to the check list of flowering plants of the Mountain Zebra National Park. Thirteen additional flowering plant species are reported from the Mountain Zebra National Park, increasing the total reported to 371 species.

scholarly journals Pollinator‐mediated interactions between cultivated papaya and co‐flowering plant species

2018 ◽  
Vol 9 (1) ◽  
pp. 587-597
Author(s):  
Raúl Badillo‐Montaño ◽  
Armando Aguirre ◽  
Miguel A. Munguía‐Rosas
Keyword(s):  
Plant Species ◽  
Flowering Plant ◽  
Flowering Plant Species

Amerila (Lepidoptera: Erebidae: Arctiinae) of Cameroon with morphological remarks on male and female genitalia

Zootaxa ◽  
2019 ◽  
Vol 4674 (2) ◽  
pp. 283-295 ◽  
Author(s):  
ŁUKASZ PRZYBYŁOWICZ ◽  
VINCENT MAICHER ◽  
GYULA M. LÁSZLÓ ◽  
SZABOLCS SÁFIÁN ◽  
ROBERT TROPEK
Keyword(s):  
Reproductive Organs ◽  
Biological Data ◽  
Individual Species ◽  
Regional Studies ◽  
Field Sampling ◽  
Male And Female ◽  
Mount Cameroon ◽  
Tiger Moths ◽  
First Time ◽  
Female Reproductive Organs

Amerila is one of the most studied Afrotropical genera of Arctiinae. However, based on a regionally constrained sample of specimens from Mount Cameroon, we show how superficial our knowledge on these tiger moths is. Among six collected Amerila species, A. femina’s female is described here for the first time, and A. mulleri and A. roseomarginata had never been recorded before in the country. Moreover, novel biological data are presented, including individual species’ elevational ranges. Finally, female reproductive organs of the genus are illustrated here for the first time. The value of such regional studies is highlighted, with some remarks on necessary requirements of such small-scaled field sampling. 

scholarly journals Temporal dynamics of sexual dimorphism in a dioecious species

2020 ◽  
Vol 126 (3) ◽  
pp. 471-480
Author(s):  
L Moquet ◽  
L Lateur ◽  
A-L Jacquemart ◽  
I De Cauwer ◽  
M Dufay
Keyword(s):  
Sexual Dimorphism ◽  
Plant Species ◽  
Temporal Dynamics ◽  
Flower Size ◽  
Flowering Plant ◽  
Floral Traits ◽  
Flower Number ◽  
Pollinator Behaviour ◽  
Flower Production ◽  
Flowering Season

Abstract Background and Aims Sexual dimorphism for floral traits is common in dioecious plant species. Beyond its significance for understanding how selection acts on plant traits through male vs. female reproductive function, sexual dimorphism has also been proposed as a possible risky characteristic for insect-pollinated plants, as it could drive pollinators to forage mostly on male plants. However, even though most flowering plant species spread their flowering across several weeks or months, the temporal variation of floral phenotypes and sexual dimorphism have rarely been investigated. Methods We performed a survey of male and female plants from the dioecious generalist-pollinated Silene dioica (Caryophyllaceae) in a common garden experiment, over two consecutive flowering seasons. Flower number and floral size were measured each week, as well as pollen quantity and viability in male plants. Key Results Sexual dimorphism was found for all investigated floral traits, with males showing an overall higher investment in flower production and flower size. Males and females showed a similar temporal decline in flower size. The temporal dynamics of daily flower number differed between sexes, with males showing a peak in the middle of their flowering season, whereas flower production by females was quite stable over time. At the scale of the experimental population, both individual and floral sex ratios appeared to vary across the flowering season. Moreover, because the onset of flowering varied among plants, the magnitude of sexual dimorphism in floral size also fluctuated strongly through time. Conclusions Capturing male/female differences with only one temporal measurement per population may not be informative. This opens stimulating questions about how pollinator behaviour and resulting pollination efficiency may vary across the flowering season.

scholarly journals Floral preferences of a neotropical stingless bee, Melipona quadrifasciata Lepeletier (Apidae: Meliponina) in an urban forest fragment

2006 ◽  
Vol 66 (2a) ◽  
pp. 463-471 ◽  
Author(s):  
Y. Antonini ◽  
R. G. Costa ◽  
R. P. Martins
Keyword(s):  
Plant Species ◽  
Urban Forest ◽  
Flowering Plant ◽  
Forest Fragment ◽  
High Similarity ◽  
Paulo State ◽  
Melipona Quadrifasciata ◽  
Belo Horizonte ◽  
Flowering Plant Species ◽  
Bee Abundance

Species of plants used by Melipona quadrifasciata Lepeletier for pollen and nectar gathering in an urban forest fragment were recorded in Belo Horizonte, Minas Gerais, Brazil. Melipona quadrifasciata visited 22 out of 103 flowering plant species. The plant species belonged mainly to Myrtaceae, Asteraceae, and Convolvulaceae (64% of the visits). Melipona quadrifasciata tended to collect pollen or nectar each time, except for Myrtaceae species, from which both pollen and nectar were collected. Bee abundance at flowers did not significantly correlate to food availability (expressed by flowering plant richness). We found a relatively high similarity (50%) between plant species used by M. quadrifasciata, which was also found in studies carried out in São Paulo State. However, low similarity (17%) was found between the results of this study and those of another done in Bahia State, Brazil.

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