scholarly journals Reproductive biology of Duranta repens L. (Verbenaceae) in relation to its environment

2008 ◽  
Vol 14 (3) ◽  
Author(s):  
D. Sharma ◽  
A. Rana ◽  
S. Chauhan ◽  
S. V. S. Chauhan
Keyword(s):  
Reproductive Biology ◽  
Pollen Fertility ◽  
Fruit Set ◽  
Environmental Changes ◽  
Ornamental Plant ◽  
Floral Structure ◽  
Visitation Rates ◽  
Floral Density ◽  
Different Seasons ◽  
Temperature Ranges

Impact of environmental changes (temperature and RH) on reproductive biology in Duranta repens (Verbenaceae) growing at ten different sites of Agra was studied. It flowers throughout the year, with optimum flowering in September. The flowers are arranged in loose clusters on terminal or axillary racemes. They are either blue or lavender in colour, hermaphrodite, actinomorphic and complete. The plants exhibit floral polymorphism (increase and decrease in number of petals and stamens) and considerable variation in extent of pollen fertility, floral density, insect pollinators and fruit-set percentage. The changes in temperature and relative humidity during the entire flowering period, was found associated with the variation in floral structure, pollen fertility and fruit-set percentage. Based on the percentage of fruit-set during different seasons of a year, there were three distinct periods, namely maximum, moderate and minimum periods. The present paper deals with the comparative view of reproductive biology of this ornamental plant in these periods. During the months of August—November when temperature ranges between 13.7-36.6 °C and RH between 79-89% the plant exhibits maximum fruit-set percentage (68-85%). This was associated with maximum flowering, increase in floral size, and increase in visitation rates of pollinators and higher degree of pollen fertility. On the other hand, with temperature reaching to the maximum (15.1-41.5 °C) and reduction in RH (14.1-41.3%), the percentage of fruit-set was reduced to the minimum (21-30%). During this period, number of flowers/plant, floral size, pollen fertility, visitation rates of pollinators were reduced to the minimum. During this period floral polymorphism was also 'recorded.

Ecology, reproductive biology and hybridization in Gaultheria L.

1991 ◽  
Vol 48 (1) ◽  
pp. 81-89 ◽  
Author(s):  
David J. Middleton
Keyword(s):  
Morphological Change ◽  
Reproductive Biology ◽  
Fruit Set ◽  
Male Sterile ◽  
Fleshy Fruits

The ecology, reproductive biology and hybridization of species in the genus Gaultheria (Ericaceae) has been investigated with particular reference to those species in Ecuador. Most species were found to be plants of disturbed ground particularly on roadside banks and forest margins. The species in Ecuador were not seen to be visited by potential pollinators although fruit set was high. No animals were seen to eat the fleshy fruits. Male sterile plants of many species from throughout the distribution of the genus were observed indicating a higher level of gynodioecism in the genus than previously thought. Empty anthers in two Ecuadorean species suggests that gynodioecism may be present in many species without any clear morphological change. A hybrid between Gaultheria myrsinoides and G. reticulata has been found in Ecuador.

Reproductive Biology and Floral Phenologies of the Sympatric Species Leptospermum myrsinoides and L. continentale (Myrtaceae)

1993 ◽  
Vol 41 (5) ◽  
pp. 527 ◽  
Author(s):  
SP Obrien ◽  
DM Calder
Keyword(s):  
Flowering Time ◽  
Genetic Control ◽  
Reproductive Biology ◽  
Pollen Viability ◽  
Sympatric Species ◽  
Anther Dehiscence ◽  
Floral Structure ◽  
Days After Anthesis ◽  
Degree Of Overlap

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.

scholarly journals Breakthroughs and new horizons in reproductive biology of rare and endangered animal species

2019 ◽  
Vol 101 (3) ◽  
pp. 514-525 ◽  
Author(s):  
Pierre Comizzoli ◽  
William V Holt
Keyword(s):  
Reproductive Biology ◽  
Allostatic Load ◽  
Environmental Changes ◽  
Future Research ◽  
Germplasm Storage ◽  
Extinction Rates ◽  
Rare And Endangered ◽  
Multiple Challenges ◽  
Basic Studies ◽  
The Impact

Abstract Because of higher extinction rates due to human and natural factors, more basic and applied research in reproductive biology is required to preserve wild species and design proper strategies leading to sustainable populations. The objective of the review is to highlight recent, inspiring breakthroughs in wildlife reproduction science that will set directions for future research and lead to more successes in conservation biology. Despite new tools and approaches allowing a better and faster understanding of key mechanisms, we still know little about reproduction in endangered species. Recently, the most striking advances have been obtained in nonmammalian species (fish, birds, amphibians, or corals) with the development of alternative solutions to preserve fertility or new information about parental nutritional influence on embryo development. A novel way has also been explored to consider the impact of environmental changes on reproduction—the allostatic load—in a vast array of species (from primates to fish). On the horizon, genomic tools are expected to considerably change the way we study wildlife reproduction and develop a concept of “precision conservation breeding.” When basic studies in organismal physiology are conducted in parallel, new approaches using stem cells to create artificial gametes and gonads, innovations in germplasm storage, and more research on reproductive microbiomes will help to make a difference. Lastly, multiple challenges (for instance, poor integration of new tools in conservation programs, limited access to study animals, or few publication options) will have to be addressed if we want reproductive biology to positively impact conservation of biodiversity.

scholarly journals Reproductive biology of four weedy Euphorbia species from Ile-Ife, Nigeria

2020 ◽  
Vol 22 (1) ◽  
pp. 1-8
Author(s):  
A.O. Bolaji ◽  
M. Idowu-Aiye ◽  
H.O. Moronfade
Keyword(s):  
Seed Dispersal ◽  
Reproductive Biology ◽  
Pollen Viability ◽  
Seedling Emergence ◽  
Floral Structure ◽  
Euphorbia Prostrata ◽  
Spread Parameters ◽  
Reproductive Phases ◽  
Vegetative Phases ◽  
Explosive Mechanism

Euphorbia heterophylla Linn., Euphorbia hirta Linn., Euphorbia hyssopifolia Linn. and Euphorbia prostrata Linn. are four noxious, yet economically important weeds, useful as phytomedicine in some parts of the world and also in Nigeria. Studies were carried out on their reproductive biology with a view to understanding the mode of their spread. Parameters investigated include number of days to seedling emergence, germinationpercentage, number of days to flowering, period to anthesis, pollinators, pollen viability, pollen size, floral structure, fruits type, seeds type, average number of fruit per plant, average number of seeds per plant and mode of seed dispersal. Results obtained showed that the seedlings of the four Euphorbia species studied emerged within 3 to 5 days; numbers of days to 50% flowering took 44 to 58 days; while flowering and fruiting continuedthroughout the remaining part of the year; thus exhibited r-strategy, expending more time and allocation of resources on their reproductive phases than their vegetative phases. Also differences existed in their stigma shape, perianth colour, perianth texture, pollen sizes, pollen viability as well as ripened colour of seed which were all significant characters that could be useful in delimiting the species. Furthermore, the study revealed that thefour species were essentially insect pollinated and their seeds dispersed by means of explosive mechanism usually characteristic of their schizocarpic fruits. This ability as well as their tendency to exhibit r-strategy could probably account for their ability to spread and invade cultivated fields, waste lands and roadsides. Keywords: Explosive mechanism, r-Strategy, Seed dispersal, Pollen viability, Seed set

Pollination ecology of the dioecious tree Commiphora guillauminii in Madagascar

2004 ◽  
Vol 20 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Nina Farwig ◽  
Emile F. Randrianirina ◽  
Friederike A. Voigt ◽  
Manfred Kraemer ◽  
Katrin Böhning-Gaese
Keyword(s):  
Plant Species ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Bird Species ◽  
Pollination Ecology ◽  
Floral Display ◽  
Flower Visitation ◽  
Visitation Rates ◽  
Male Flowers ◽  
Female Flowers

In dioecious plant species differences in morphology and resources between female and male flowers can have consequences for flower visitation rates. Female flowers sometimes lack pollen and can be less attractive to pollinators than male flowers. We studied the pollination ecology of the dioecious tree Commiphora guillauminii in a dry deciduous forest in western Madagascar. We recorded floral display, visiting insect species and visitation rates for female and male trees. The results showed that female trees produce significantly larger but fewer flowers per inflorescence than male ones. Number of flowers per tree did not differ between the sexes. During 270 observation-hours we observed 17 insect and two bird species visiting the flowers. Mean visitation rates of male flowers were 6.1 times higher than those of female flowers (1.07 vs. 0.18 visitors per flower h−1). Visitation rates to female and male trees showed similar daily and seasonal patterns. Fruit set (2.9%) was low, which could have been caused by pollinator or pollen limitation. This study suggests that dioecy may pose a risk for fruit set and, potentially, reproductive success for plant species with depauperate pollinator faunas on islands such as Madagascar.

scholarly journals Reproductive Biology of a Medicinal Orchid Satyarium Nepalense (Orchidaceae) in the Nepalese Himalayas

2020 ◽  
pp. 15-18
Author(s):  
Babu Ram Paudel ◽  
Brihaspati Poudel
Keyword(s):  
Natural History ◽  
Spatial Variation ◽  
Reproductive Biology ◽  
Important Implication ◽  
Fruit Set ◽  
Medicinal Uses ◽  
Floral Visitors ◽  
Medicinal Orchid ◽  
Two Populations ◽  
Very High

Satyrium nepalense is a terrestrial medicinal orchid of the Himalayas. Although, the ecology and medicinal uses of this orchid is well known, little is known about its reproductive mechanism. In this study, we explored the natural history and reproductive biology of S. nepalense and tested their potential spatial variation. We observed the floral visitors and natural fruit set of S. nepalense at its two populations. We found that, despite the presence of outcrossing features, this orchid did not receive any diurnal floral visitors. The natural fruit set was very high (>90.0%) at both the sites, suggesting the possibility of autonomous selfing. This finding may have important implication for the further study to explore how autonomous selfing evolves in a member of the predominately outcrossing genus. Moreover, the finding of this study provides important insight to develop efficient protocol for its conservation.

scholarly journals Reproductive biology traits affecting productivity of sour cherry

2013 ◽  
Vol 48 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Milica Fotiric Aksic ◽  
Vera Rakonjac ◽  
Dragan Nikolic ◽  
Gordan Zec
Keyword(s):  
Flowering Time ◽  
Reproductive Biology ◽  
Pollen Germination ◽  
Fruit Set ◽  
Principal Component ◽  
Sour Cherry ◽  
High Genetic Diversity ◽  
Breeding Programs ◽  
Factors Affecting ◽  
Yield Efficiency

The objective of this work was to evaluate variability in reproductive biology traits and the correlation between them in genotypes of 'Oblačinska' sour cherry (Prunus cerasus). High genetic diversity was found in the 41 evaluated genotypes, and significant differences were observed among them for all studied traits: flowering time, pollen germination, number of fruiting branches, production of flower and fruit, number of flowers per bud, fruit set, and limb yield efficiency. The number of fruiting branches significantly influenced the number of flower and fruit, fruit set, and yield efficiency. In addition to number of fruiting branches, yield efficiency was positively correlated with fruit set and production of flower and fruit. Results from principal component analysis suggested a reduction of the reproductive biology factors affecting yield to four main characters: number and structure of fruiting branches, flowering time, and pollen germination. Knowledge of the reproductive biology of the 'Oblačinska' genotypes can be used to select the appropriate ones to be grown or used as parents in breeding programs. In this sense, genotypes II/2, III/9, III/13, and III/14 have very good flower production and satisfactory pollen germination.

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