Relationships between flowering phenology, plant size, and female reproductive output in a dioecious shrub, Ilex leucoclada (Aquifoliaceae)

2006 ◽  
Vol 84 (12) ◽  
pp. 1860-1869 ◽  
Author(s):  
Takeshi Torimaru ◽  
Nobuhiro Tomaru
Keyword(s):  
Reproductive Output ◽  
Fruit Set ◽  
Flowering Phenology ◽  
Plant Size ◽  
Beech Forest ◽  
Major Effect ◽  
Onset Date ◽  
Dioecious Species ◽  
Physiological Factors ◽  
Flowering Onset

Flowering phenology is critical for reproduction in dioecious species, but selection on timing of flowering may be weakened by physiological factors such as plant size, and external factors such as climate. We investigated the flowering phenology of male and female adults, and female reproductive output, in 10 patches with various sex ratios, of the dioecious shrub Ilex leucoclada (Maxim.) Makino over three consecutive years in an old-growth beech forest. Sexual dimorphism was observed in flowering amplitude, but not in other traits examined, including flowering onset date, duration, peak date, and synchrony with plants of the opposite sex in the population. Plant size had a consistent, positive effect on flowering amplitude in both sexes throughout the study period, but its effects on other factors, including the extent of fruit set, varied. Females in mixed patches showed higher fruit set than those in female patches. Furthermore, although the reproductive output of the female I. leucoclada plants is likely to be affected by flowering phenological traits in the mixed patches, the importance of these factor is probably modulated by other variables, including precipitation (which had a major effect on male flowering patterns) and the spatial distribution of the males.

scholarly journals Flowering Phenology Adjustment and Flower Longevity in a South American Alpine Species

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 461
Author(s):  
Mary T. K. Arroyo ◽  
Ítalo Tamburrino ◽  
Patricio Pliscoff ◽  
Valeria Robles ◽  
Maria Colldecarrera ◽  
...  
Keyword(s):  
Natural Populations ◽  
Flowering Phenology ◽  
Snow Accumulation ◽  
Growth Potential ◽  
Controlled Study ◽  
Temperature Threshold ◽  
Flower Longevity ◽  
Passive Warming ◽  
Alpine Species ◽  
Flowering Onset

Delayed flowering due to later snowmelt and colder temperatures at higher elevations in the alpine are expected to lead to flowering phenological adjustment to prevent decoupling of peak flowering from the warmest time of the year, thereby favoring pollination. However, even if flowering is brought forward in the season at higher elevations, an elevational temperature gap is likely to remain between the high- and low-elevation populations of a species at the time these reach peak flowering on account of the atmospheric reduction in temperature with increasing elevation. The negative effect of this temperature gap on pollination could be compensated by plastically-prolonged flower life spans at higher elevations, increasing the probability of pollination. In a tightly temperature-controlled study, the flowering phenology adjustment and flower longevity compensation hypotheses were investigated in an alpine species in the Andes of central Chile. The snow free period varied from 7 to 8.2 months over 810 m elevation. Temperatures were suitable for growth on 82–98% of the snow free days. Flowering onset was temporally displaced at the rate of 4.6 d per 100 m increase in elevation and flowering was more synchronous at higher elevations. Flowering phenology was adjusted over elevation. The latter was manifest in thermal sums tending to decrease with elevation for population flowering onset, 50% flowering, and peak flowering when the lower thermal limit for growth (TBASE) was held constant over elevation. For TBASE graded over elevation so as to reflect the growing season temperature decline, thermal sums did not vary with elevation, opening the door to a possible elevational decline in the thermal temperature threshold for growth. Potential flower longevity was reduced by passive warming and was more prolonged in natural populations when temperatures were lower, indicating a plastic trait. Pollination rates, as evaluated with the Relative Pollination Rate index (RPR), when weighted for differences in floral abundance over the flowering season, declined with elevation as did fruit set. Contrary to expectation, the life-spans of flowers at higher elevations were not more prolonged and failed to compensate for the elevational decrease in pollination rates. Although strong evidence for phenological adjustment was forthcoming, flower longevity compensation did not occur over Oxalis squamata’s elevational range. Thus, flower longevity compensation is not applicable in all alpine species. Comparison with work conducted several decades ago on the same species in the same area provides valuable clues regarding the effects of climate change on flowering phenology and fitness in the central Chilean alpine where temperatures have been increasing and winter snow accumulation has been declining.

The importance of recruitment patterns versus reproductive output in the persistence of a short-range endemic shrub in a highly fragmented landscape of south-western Australia

2012 ◽  
Vol 60 (7) ◽  
pp. 643 ◽  
Author(s):  
Neil Gibson ◽  
Colin Yates ◽  
Margaret Byrne ◽  
Margaret Langley ◽  
Rujiporn Thavornkanlapachai
Keyword(s):  
Short Range ◽  
Reproductive Output ◽  
Fruit Set ◽  
Seedling Recruitment ◽  
Fragment Size ◽  
Fragmented Landscape ◽  
Recruitment Failure ◽  
Degree Of Isolation ◽  
Number Of Seeds ◽  
Significant Mortality

Calothamnus quadrifidus subsp. teretifolius A.S.George & N.Gibson is a short-range endemic shrub whose habitat has been greatly reduced by clearing for agriculture. Reproductive output was high in all populations sampled, although there were large differences among populations in fruit set, the number of seeds per fruit and seed germination. These traits showed no relationship to population size, degree of isolation, or fragment size, which contrasts strongly with the patterns found in a widespread congener. Demographic studies in remnants with an intact understorey showed stable adult populations with continuous seedling recruitment. In contrast, there was consistent widespread failure of seedling and juvenile recruitment in degraded roadside remnants that also showed significant mortality of reproductive adults. In these degraded remnants, recruitment failure appears to be the primary cause of species decline.

scholarly journals Performance of Iris variegata genotypes in different light conditions: Flowering phenology and reproductive output

Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 679-694 ◽  
Author(s):  
Uros Zivkovic ◽  
Danijela Miljkovic ◽  
Natasa Barisic-Klisaric ◽  
Aleksej Tarasjev ◽  
Stevan Avramov
Keyword(s):  
Reproductive Output ◽  
Seed Mass ◽  
Flowering Phenology ◽  
Light Treatment ◽  
Biological Research ◽  
Congeneric Species ◽  
Light Conditions ◽  
Flowering Pattern ◽  
Experimental Garden ◽  
Effect Of Light

We analyzed genetic variability and phenotypic plasticity of flowering pattern and reproductive success in 97 clonal genotypes of Iris variegata originating from contrasting light habitats in Deliblato Sands and expressed under different experimental light conditions. Rhizome segments were taken from each of these clones and transplanted in the experimental garden near the Institute for Biological Research in Belgrade. Significant differences between genotypes were found for two traits (start of flowering, average flowering time). Genotypes originating from open and understory habitats significantly differed for three traits (number of flowers, number of capsules/number of flowers, seed mass/capsule). Significant effect of light treatment were found for three traits (number of capsules/number of flowers, seed mass/capsule, average seed mass). Statistically significant correlations between explored traits were generally similar but also to some extent habitat and treatment specific. Comparing these results with research carried out on congeneric species we noted that there are similar responses for some traits, but also significant differences in some components of flowering and fruiting success.

scholarly journals Reproductive biology of Ophiorrhiza caudata C.E.C.Fisch. (Rubiaceae), an endemic and endangered creeping perennial herb of the Western Ghats, India

2021 ◽  
Vol 13 (13) ◽  
pp. 20056-20065
Author(s):  
Maria Theresa ◽  
Appukuttan Kamalabai Sreekala ◽  
Jayalakshmi Mohanlal
Keyword(s):  
Seedling Establishment ◽  
Fruit Set ◽  
Floral Morphology ◽  
Climatic Factors ◽  
Monsoon Season ◽  
Natural Habitat ◽  
Flowering Phenology ◽  
Perennial Herb ◽  
In The Wild ◽  
The Western Ghats

Ophiorrhiza caudata is a creeping, perennial herb distributed along wet and shady areas. The species is distylous with two distinct floral morphs: pin and thrum. Flowering usually occurs during the monsoon season. No particular difference was noticed in the flowering phenology of the two morphs. Presently the species is self-incompatible, however, it shows a tendency towards intramorph compatibility. Fruit set is above 60% in open pollination and intermorph pollination. Bees and butterflies are the major pollinators. The pollen flow between the two floral morphs varies depending upon floral morphology and pollinators. Fruit is a bi-valved capsule which dehisces by a splashing drop mechanism. The seeds are very minute. The rate of seed germination and seedling establishment in the wild condition is very poor due to adverse climatic factors. Ophiorrhiza caudata is struggling for survival in its natural habitat, where habitat fragmentation, climatic factors and poor seedling establishment could account for its narrow distribution.

PHYSIOLOGICAL FACTORS IN TOMATO FRUIT-SET

1952 ◽  
Vol 39 (5) ◽  
pp. 310-317 ◽  
Author(s):  
A. C. Leopold ◽  
Frances I. Scott
Keyword(s):  
Fruit Set ◽  
Tomato Fruit ◽  
Physiological Factors

Flowering phenology of tropical-alpine dwarf trees on Mount Kinabalu, Borneo

2004 ◽  
Vol 20 (5) ◽  
pp. 563-571 ◽  
Author(s):  
Gaku Kudo ◽  
Shizuo Suzuki
Keyword(s):  
Flowering Phenology ◽  
Plant Size ◽  
Sympatric Species ◽  
Fruit Production ◽  
Flowering Pattern ◽  
Flowering Synchrony ◽  
Mount Kinabalu ◽  
Main Plot ◽  
Tropical Alpine ◽  
Summit Region

The flowering phenology of five alpine dwarf-tree species was observed in the summit region (3900–3950 m elevation) of Mt. Kinabalu on Borneo Island from March 1998 to November 2001. For each target species, 20–50 individual plants were numbered in two observation plots and the number of inflorescences was monitored at 2–3-mo intervals. The flowering patterns varied among species. Rhododendron buxifolium bloomed extensively every March–May at the main plot but the flowering pattern at the subplot was less predictable. Mass flowering occurred in March 1998 when drought stress was very severe due to an El Niño event. Rhododendron ericoides showed continuous flowering throughout the year and high synchrony between the plots. Extensive flowering of Leptospermum recurvum occurred synchronously within and between plots in the early half of 1999, then flowering activity decreased greatly. Photinia davidiana showed an annual flowering cycle but the timing of the peak flowering differed between the plots. Vaccinium stapfianum showed synchronous flowering between the plots and the flowering peak appeared at longer than 1-y intervals. Plant size was positively correlated with mean flower production in all species, and with the flowering frequency of R. ericoides, R. buxifolium, and V. stapfianum at one of the plots at least. Two fleshy-fruited species, P. davidiana and V. stapfianum, had high selfing ability for fruit production and showed relatively low flowering synchrony among individuals in comparison with the other species. These results indicate that the trigger for initiation of flowering may differ among sympatric species in a tropical-alpine ecosystem at least in normal years.

Is reproductive allocation in Senecio vulgaris plastic?

Botany ◽  
2009 ◽  
Vol 87 (5) ◽  
pp. 475-481 ◽  
Author(s):  
Jacob Weiner ◽  
Lars Rosenmeier ◽  
Emma Soy Massoni ◽  
Josep Nogués Vera ◽  
Eva Hernández Plaza ◽  
...  
Keyword(s):  
Reproductive Output ◽  
Plant Biomass ◽  
Seed Mass ◽  
Plant Size ◽  
Reproductive Allocation ◽  
Life Cycles ◽  
Nutrient Level ◽  
Significant Shift ◽  
Senecio Vulgaris ◽  
The Relationship

Several purported cases of plasticity in plant allocation patterns appear to be the effects of size and allometric growth (“apparent plasticity”). To ask whether there is true plasticity (i.e., a change in the allometric trajectory) in reproductive allocation in Senecio vulgaris  L., we grew S. vulgaris plants at high and low levels of water, nutrients, and competition, and analyzed the relationship between vegetative and seed biomass. Plant size was the major determinant of reproductive output, accounting for 83% of the variation in log (seed mass). There were also significant effects of the treatments that were not due to size, accounting for an additional 9% of the variation. The treatments affected the allometric coefficient (intercept), not the allometric exponent (slope) of the relationship, reflecting a small but significant shift in the efficiency of conversion of total plant biomass into reproductive biomass. In a second experiment, we grew S. vulgaris plants at three nutrient levels and allowed all individuals to complete their life cycles. Again, nutrient level had a small but significant effect on the allometric coefficient. Plasticity in reproductive allocation exists, but is very limited. The primary effects of the environment on the reproductive output of S. vulgaris occur via plant size.

Shoot ontogeny in Fraxinus pennsylvanica (green ash). II. Development of the inflorescence

1989 ◽  
Vol 67 (7) ◽  
pp. 1966-1978 ◽  
Author(s):  
W. R. Remphrey
Keyword(s):  
Fruit Set ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Dioecious Species ◽  
Male And Female ◽  
Floral Buds ◽  
Growing Seasons ◽  
Female Inflorescence ◽  
Mature Flower ◽  
Floral Apex

From initiation to fruit set, which occurs over three growing seasons, eight stages are recognized in the development of axillary inflorescences in the dioecious species Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern, (green ash). In the first season, buds are initiated in the axils of foliage leaves. As the shoots expand in the following spring, the buds complete their development. Although similar at first, differences begin to emerge between vegetative and inflorescence buds in that the latter produce robust second-order meristems, the incipient paracladia, protruding close to the original apex. After about 3–4 weeks, when the initiation of such buds is complete, the terminal and subtending lateral meristems present on each axis develop into a three-membered cluster of floral buds. There was a mean of 214.3 ± 12.2 floral buds initiated per female inflorescence, and the number generally increased with the length of the associated shoot. A ridge, the incipient perianth, begins to form around the periphery of each rounded floral apex. Male and female floral buds are not distinguishable at this stage, but the inflorescence buds are distinctly different from vegetative buds. The male and female buds then diverge in their development in that an identation forms at the summit of the incipient gynoecium and male buds initiate two or three anthers. By autumn, the gynoecium is distinctly conical, with an orifice at its summit, and the anthers are lobed. There is lobing of the perianth ridge, but in the mature flower distinct organs traceable to such lobes could not readily be identified.

scholarly journals Flowering phenology, fruiting success and progressive deterioration of pollination in an early-flowering geophyte

2010 ◽  
Vol 365 (1555) ◽  
pp. 3187-3199 ◽  
Author(s):  
James D. Thomson
Keyword(s):  
Fruit Set ◽  
Flowering Phenology ◽  
Bumble Bee ◽  
Late Flowering ◽  
Progressive Deterioration ◽  
Pollination Limitation ◽  
Hand Pollination ◽  
Western Colorado ◽  
Spatio Temporal ◽  
Erythronium Grandiflorum

Spatio-temporal patterns of snowmelt and flowering times affect fruiting success in Erythronium grandiflorum Pursh (Liliaceae) in subalpine western Colorado, USA. From 1990 to 1995, I measured the consistency across years of snowmelt patterns and flowering times along a permanent transect. In most years since 1993, I have monitored fruit set in temporal cohorts (early- to late-flowering groups of plants) at one site. To assess ‘pollination limitation’, I have also conducted supplemental hand-pollination experiments at various times through the blooming season. The onset of blooming is determined by snowmelt, with the earliest years starting a month before the latest years owing to variation in winter snowpack accumulation. Fruit set is diminished or prevented entirely by killing frosts in some years, most frequently but not exclusively for the earlier cohorts. When frosts do not limit fruit set, pollination limitation is frequent, especially in the earlier cohorts. Pollination limitation is strongest for middle cohorts: it tends to be negated by frost in early cohorts and ameliorated by continuing emergence of bumble-bee queens in later cohorts. This lily appears to be poorly synchronized with its pollinators. Across the years of the study, pollination limitation appears to be increasing, perhaps because the synchronization is getting worse.

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