Differences in plant size and flower production between hermaphrodites and females of two gynodioecious Chionographis (Liliaceae)

1996 ◽  
Vol 74 (1) ◽  
pp. 150-153 ◽  
Author(s):  
Masayuki Maki
Keyword(s):  
Frequency Distribution ◽  
Reproductive Effort ◽  
Plant Size ◽  
Flowering Plants ◽  
Size Class ◽  
Minimum Size ◽  
Dioecious Species ◽  
Flower Production ◽  
Flowering Season ◽  
Secondary Sex Characters

Plant size and flower production were compared between female and hermaphroditic plants of two gynodioecious Chionographis. Frequency distribution of size and minimum size class of flowering plants were not different between two sex morphs in both Chionographis. In C. japonica ssp. hisauchiana, females produced more ovuliferous flowers than hermaphrodites, although the total number of flowers were not significantly different between two sex morphs. In contrast, hermaphrodites of C. japonica var. kurohimensis exceeded females in the total number of flowers, whereas the number of ovuliferous flowers was not significantly different between two sex morphs. Reproductive effort at flowering season is not different between females and hermaphrodites. These little differences in secondary sex characters, compared with dioecious species, are probably due to the selfing of hermaphrodites and weaknesses in gender specialization. Keywords: Chionographis, flower production, gynodioecy, plant size, secondary sex characters.

scholarly journals Sex dimorphism in dioecious Palmer amaranth (Amaranthus palmeri) in response to water stress

Planta ◽  
2021 ◽  
Vol 254 (1) ◽  
Author(s):  
Mohsen B. Mesgaran ◽  
Maor Matzrafi ◽  
Sara Ohadi
Keyword(s):  
Water Stress ◽  
Weed Management ◽  
Amaranthus Palmeri ◽  
Ecological Management ◽  
State University ◽  
Dioecious Species ◽  
Seed Output ◽  
Flowering Asynchrony ◽  
Secondary Sex Characters ◽  
Response To Water

Abstract Main conclusion Phenological isolation can potentially reduce seed output and may be exploited as a novel tool for ecological management of dioecious weeds. Abstract Dioecious plants may benefit from a maximized outcrossing and optimal sex-specific resource allocation; however, this breeding system may also be exploited for weed management. Seed production in dioecious species is contingent upon the co-occurrence and co-flowering of the two genders and can be further disturbed by flowering asynchrony. We explored dimorphism in secondary sex characters in Amaranthus palmeri, and tested if reproductive synchrony can be affected by water stress. We have used seeds of A. palmeri from California, Kansas and Texas, and studied secondary sex characters under natural conditions and in response to water stress. Seeds of A. palmeri from California (CA) and Kansas (KS) were cordially provided by Dr. Anil Shrestha (California State University, Fresno, California) and Dr. Dallas E. Peterson (Kansas State University, Manhattan, Kansas), respectively. Seeds of a third population were collected from mature plants (about 30 plants) from a set-aside field in College Station, Texas. A. palmeri showed no sexual dimorphism with regard to the timing of emergence, plant height, and relative growth rate. While the initiation of flowering occurred earlier in males than females, females preceded males in timing of anthesis. Water stress delayed anthesis in males to a greater extent than females increasing the anthesis mismatch between the two sexes by seven days. Our data provide the first evidence of environment-controlled flowering asynchrony in A. palmeri. From a practical point of view, phenological isolation can potentially reduce seed output and may be exploited as a novel tool for ecological management of dioecious weeds.

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.

Demographic variation between populations of Caladenia orientalis - a fire-managed threatened orchid

2009 ◽  
Vol 57 (4) ◽  
pp. 326 ◽  
Author(s):  
Fiona Coates ◽  
Michael Duncan
Keyword(s):  
Reproductive Effort ◽  
Fire Regimes ◽  
Plant Size ◽  
Biological Information ◽  
Time Since Fire ◽  
Pollen Transport ◽  
Study Sites ◽  
Site Population ◽  
Future Management

Caladenia orientalis (G.W.Carr) Hopper & A.P.Br. is a critically endangered orchid. The largest known populations are confined to fire-managed coastal heathland in southern Victoria. Trends in population dynamics at two closely occurring sites were evaluated against time since fire and rainfall, between 2000 and 2008, to provide ecological and biological information relevant to population management. At both sites, decreased plant size was inversely correlated with time since fire and the number of non-reproductive plants was positively correlated with time since fire. Rates of flowering were inversely correlated with time since fire at only one site (Population 2). The vegetation at this site rapidly accumulated after fire, whereas recovery was relatively slow at the other site. Rainfall was not correlated with rates of flowering or leaf width at either of the study sites, although there was a weak inverse relationship between rainfall and the number of non-reproductive plants at one site (Population 1). Rates of pollen transport and fruit set were within reported ranges for deceptive species. Fruiting plants were significantly smaller in the following year, whereas non-reproductive plants remained the same size. The results suggest that there may be costs associated with reproductive effort, and that hand-pollinating plants to boost seed production may lead to decreased plant size in the following year. Annual variation in rates of flowering may be influenced by previous reproductive effort. However, long-term population trends are better explained by competition from dominant shrubs, which become increasingly abundant with a lack of fire. Future management prescriptions should include site-specific fire regimes to maintain an open heathland.

Dry weight and resource allocation patterns among individuals in populations of Plantago major and P. rugelii

1982 ◽  
Vol 60 (11) ◽  
pp. 2424-2439 ◽  
Author(s):  
W. R. Hawthorn ◽  
P. B. Cavers
Keyword(s):  
Frequency Distribution ◽  
Reproductive Effort ◽  
Natural Populations ◽  
Dry Weight ◽  
Life History Trait ◽  
Plantago Major ◽  
Allocation Pattern ◽  
Plant Weight ◽  
Frequency Distributions ◽  
Allocation Patterns

The frequency distributions of log plant weight in 1st-year plants of Plantago major L. and P. rugelii Decne. were studied in greenhouse experiments, including an investigation of associated differences in allocation patterns to plant parts between individuals in various weight classes. The frequency distributions of log plant weight of both plantains were strongly negatively skewed (many large plants and few small ones) at the lowest sowing density, where little or no mortality occurred during the course of the study. At two higher sowing densities significant mortality was noted and the frequency distributions tended to "log normality" or to a significant platykurtosis. The presence of bromegrass (Bromus inermis Leyss.) reduced the weight of individual plantains and resulted in frequency distributions that were essentially "log normal." Growing the two plantains together did not alter the shapes of the frequency distributions achieved in monocultures with and without grass. A possible pattern of changes in the frequency distribution of log plant weight with the passage of time is briefly discussed. Significant differences were observed in the allocation patterns of individuals of P. major within a population to roots, caudices, leaves, supporting reproductive structures, and seeds. The allocation patterns were not normally distributed according to plant weight; thus the use of average values of allocation pattern for the population as a whole should be viewed with caution. The proportional allocation to seeds (reproductive effort) by individuals of P. major from increasingly larger weight classes generally increased at an exponential rate, and more rapidly than simultaneous decreases in root and caudex allocation. The greatest reproductive effort and the greatest number of seeds per plant of P. major were associated with the strongest negative skewness of frequency distribution of log plant weight. First-year plants of P. rugelii exhibited a different response. Very few flowered during the study. However, in a variety of treatments the allocation to root and caudex by individuals which differed in biomass by as much as two orders of magnitude was remarkably constant at about 23%. In contrast, the allocation to belowground structures was much more variable among individuals of P. major, ranging from 50% or more by the smallest individuals to less than 5% by the largest plants. This life-history trait could partly account for the greater survival over winter and longevity observed in natural populations of P. rugelii compared with those of P. major.

Sistem Pakar Diagnosis Hama dan Penyakit pada Tanaman Bunga Sedap Malam dengan Dempster Shafer

2020 ◽  
Vol 3 (2) ◽  
pp. 40-45
Author(s):  
Maulidina Nindhy Prastiwi ◽  
Uky Uky Yudatama ◽  
Nugroho Agung Prabowo
Keyword(s):  
Expert System ◽  
Flowering Plants ◽  
Trust Value ◽  
The Public ◽  
Flower Production ◽  
Pests And Diseases

Nightly flower plants are one of the flower plants that are much in demand by the public. However, as time goes by the production of savory flower plants determines which one of the causes is caused by pests and diseases. Introduction of pests and diseases and its control sometimes not all farmers know it. This research develops an expert system that can help farmers diagnose pests and diseases that attack night flowering plants with the Dempster Shafer method. The results of this study are the application of an expert system that uses pests and tuberose flower diseases. This system will issue this edition to the publication of night flower pests and diseases inputted by users. The amount of this trust value is the result of calculations using the Dempster Shafer method. The conclusion in this study is that an expert system using the Dempster Shafer method for approval to release pests and diseases of the nightly flower plants is very helpful in overcoming the problem of improving the quality of the nightly flower production.

Energy budget for a stream population of the freshwater clam, Sphaerium striatinum Lamarck (Bivalvia: Pisidiidae)

1984 ◽  
Vol 62 (12) ◽  
pp. 2410-2417 ◽  
Author(s):  
Daniel J. Hornbach ◽  
Thomas E. Wissing ◽  
Albert J. Burky
Keyword(s):  
Energy Budget ◽  
Standing Crop ◽  
Production Efficiency ◽  
Reproductive Effort ◽  
Energy Partitioning ◽  
Minimum Size ◽  
Energy Needs ◽  
Annual Productivity ◽  
Deposit Feeding ◽  
Growth And Reproduction

An annual energy budget was constructed for a stream population of Sphaerium striatinum. The annual productivity (P) was 2.79 g C∙m−2∙year−1 and the average standing crop biomass (B) was 0.58 g C∙m−2; the resulting annual P:B ratio of 4.58 is below that expected for a bivoltine animal. The low value for reproductive effort (Re:P = 16.1%) may partially be attributed to the ovoviviparous, iteroparous nature of this population. A strategy of partitioning a large proportion of production to growth (G:P = 83.9%) may insure a high probability of attaining the minimum size necessary for reproduction. Production accounts for 44% of assimilation (A) with 56% of A lost through respiration. The net production efficiency (P:A = 44%) is high and indicates that this population is efficient in partitioning energy to growth and reproduction. The population must consume (C) 10.57 g C∙m−2∙year−1 to meet its energy needs. Only 35% of this could be accounted for by filter feeding; the remainder may have come from deposit feeding. Comparisons of P, P:B, Re:P and P:A with published values for corbiculacean clams indicates that this population of S. striatinum is one of the most productive and efficient in its energy partitioning of populations studied to date.

scholarly journals Integrated dominance mechanisms regulate reproductive architecture in Arabidopsis thaliana and Brassica napus

2021 ◽  
Author(s):  
Catriona H Walker ◽  
Cara D Wheeldon ◽  
Tom Bennett
Keyword(s):  
Arabidopsis Thaliana ◽  
Brassica Napus ◽  
Resource Use ◽  
Reproductive Effort ◽  
Seed Set ◽  
Developmental Stages ◽  
Reproductive Development ◽  
Flowering Plants ◽  
Negative Feedbacks ◽  
Spatio Temporal

Abstract The production of seed in flowering plants is complicated by the need to first invest in reproductive shoots, inflorescences, flowers and fruit. Furthermore, in many species, it will be months between plants generating flowers and setting seed. How can plants therefore produce an optimal seed-set relative to environmental resources when the ‘reproductive architecture’ that supports seed-set needs to be elaborated so far in advance? Here, we address this question by investigating the spatio-temporal control of reproductive architecture in Arabidopsis (Arabidopsis thaliana) and Brassica napus. We show that resource- and resource-related signals such as substrate volume play a key role in determining the scale of reproductive effort, and that this is reflected in the earliest events in reproductive development, which broadly predicts the subsequent reproductive effort. We show that a series of negative feedbacks both within and between developmental stages prevent plants from over-committing to early stages of development. These feedbacks create a highly plastic, homeostatic system in which additional organs can be produced in the case of reproductive failure elsewhere in the system. We propose that these feedbacks represent an ‘integrated dominance’ mechanism that allows resource use to be correctly sequenced between developmental stages to optimise seed set.

scholarly journals Effects of trampling on a terrestrial orchid environment

Lankesteriana ◽  
2015 ◽  
Vol 7 (1-2) ◽  
Author(s):  
Marilyn Light ◽  
Michael MacConaill
Keyword(s):  
Direct Effect ◽  
Human Disturbance ◽  
Reproductive Effort ◽  
Flowering Plants ◽  
Terrestrial Orchid ◽  
Soil Communities

Orchids and soil communities that support them may be affected when we monitor or conduct inves- tigative procedures, or through tourism especially during the blooming season, but this has never been investigated or quantified (Light 2004). The immedi- ate and direct effect of human disturbance including crushing of flowering plants and seedlings is obvious: broken stems are unlikely to resume growth and a season’s reproductive effort can be lost. 

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