Reproduction of Viola mirabilis in relation to light and nutrient availability

Mixed mating strategies in plants, such as chasmogamy and cleistogamy, may have evolved to optimize reproductive response to local, often variable, environmental conditions. A 2-year field experiment was conducted to examine the effects of light and nutrient availability on growth and chasmogamous and cleistogamous flower and fruit production in Viola mirabilis, a perennial forest understory herb. Using a factorial design, we examined whether the mode of reproduction or reproductive output of V. mirabilis would be influenced by a repeated fertilizer application and (or) gradual shading with artificial plants. In this population of V. mirabilis, the predominant mode of reproduction during both study years was chasmogamy. In the 2nd year of study, the number of both chasmogamous and cleistogamous flowers per plant decreased with decreasing light intensity, while the increased nutrient supply had no effect on flower or fruit production or plant growth. In addition, the proportion of cleistogamous flowers was smaller for shaded plants. However, the change in the proportion of cleistogamous or chasmogamous flowers from 1993 to 1994 was not affected by shading or fertilization. The production of cleistogamous flowers correlated positively with final total leaf area during both study years, while no correlation was found between the number of chasmogamous flowers and leaf area. In most studies, chasmogamy has been found to be dependent on plant size and favourable environmental conditions, whereas cleistogamy is generally considered to be relatively independent of these factors. However, our results suggest that only plants reaching a large size were capable of producing cleistogamous flowers in addition to chasmogamous flowers produced earlier in the season. Also, it seems that the general assumption of cleistogamic reproduction as a more advantageous mode of reproduction in poor light conditions compared with chasmogamy does not apply to V. mirabilis. Key words: chasmogamy, cleistogamy, light, nutrients, reproductive success, Viola mirabilis.

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Reproductive system of a mixed-mating plant responds to climate perturbation by increased selfing

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2013.1336 ◽

2013 ◽

Vol 280 (1766) ◽

pp. 20131336 ◽

Cited By ~ 9

Author(s):

N. T. Jones ◽

B. C. Husband ◽

A. S. MacDougall

Keyword(s):

Population Structure ◽

Environmental Change ◽

Inbreeding Depression ◽

Reproductive System ◽

Fruit Production ◽

Mixed Mating ◽

Reproductive Assurance ◽

Pollinator Visitation ◽

Chasmogamous Flowers

How plants respond to climatic perturbations, which are forecasted to increase in frequency and intensity, is difficult to predict because of the buffering effects of plasticity. Compensatory adjustments may maintain fecundity and recruitment, or delay negative changes that are inevitable but not immediately evident. We imposed a climate perturbation of warming and drought on a mixed-mating perennial violet, testing for adjustments in growth, reproduction and mortality. We observed several plasticity-based buffering responses, such that the climatic perturbation did not alter population structure. The most substantial reproductive adjustments, however, involved selfing, with a 45% increase in self-pollination by chasmogamous flowers, a 61% increase in the number of cleistogamous flowers that produced at least one fruit and an overall 15% increase in fruit production from selfed cleistogamous flowers. Reproductive assurance thus compensated for environmental change, including low pollinator visitation that occurred independently of our climate treatment. There was also no immediate evidence for inbreeding depression. Our work indicates that plants with vegetative and reproductive flexibility may not be immediately and negatively affected by a climatic perturbation. The stabilizing effects of these reproductive responses in the long term, however, may depend on the implications of significantly elevated levels of selfing.

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Stomatal density, leaf area and plant size variation of Rhizophora mangle (Malpighiales: Rhizophoraceae) along a salinity gradient in the Mexican Caribbean

Revista de Biología Tropical ◽

10.15517/rbt.v65i2.24372 ◽

2017 ◽

Vol 65 (2) ◽

Cited By ~ 3

Author(s):

Joanne R. Peel ◽

Maria C. Mandujano Sanchez ◽

Jorge Lopez Portillo ◽

Jordan Golubov

Keyword(s):

Leaf Area ◽

Environmental Conditions ◽

High Salinity ◽

Stomatal Density ◽

Salinity Gradient ◽

Abiotic Factors ◽

Tree Height ◽

Plant Size ◽

Leaf Length ◽

Low Salinity

In community ecology, the knowledge of abiotic factors, that determine intraspecific variability in ecophysiological and functional traits, is important for addressing major questions, such as plant community assembly and ecosystem functioning. Mangroves have several mechanisms of resistance to salinity and most species exhibit some xeromorphic features in order to conserve water. Leaf area and stomatal density play an important role in maintaining water balance, and gas exchange is regulated by their aperture and density, two traits that vary intraspecifically in response to environmental conditions, such as water stress and salinity. In this study, we evaluated the effects of salinity on stomatal density, leaf area and plant size in R. mangle and we tested for associations among the three variables, across three sites along a natural salinity gradient in the Xel-Há Park, Quintana Roo, Mexico. We hypothesized that high salinity sites would produce smaller plants, with smaller leaves, and fewer stomata. Three sampling sites with different environmental conditions were chosen and salinities were monitored monthly. A total of 542 plants were tagged and tree heights and diameters were measured for each individual within each of the three sampling sites. Three leaves from 20 trees from each site were measured to determine leaf area. Stomatal densities were determined in each leaf using nail polish casts, examining ten 1 mm squares per leaf under an optical microscope. A principal component analysis was used to assess association between tree height, leaf area, and stomatal density for each plot. The salinity gradient was reflected in plant size, producing smaller plants at the higher salinity site. The largest leaves were found at the low salinity site (51.2 ± 24.99 cm2). Leaf length was not correlated to plant size (LL vs. tree height: r= 0.02, P= 0.8205; LL vs. trunk diameter: r= 0.03, P= 0.7336), so we concluded that leaf length is an environmentally plastic trait of red mangroves that may vary as a function of environmental conditions, such as hydric stress caused by elevated salinity. The larger leaves from the low salinity site had lower densities of stomata (65.0 stomata.mm2 SD= 12.3), and increasing salinities did not decrease stomatal density (intermediate salinity site: 73.4 stomata.mm2 SD= 13.5; high salinity site: 74.8 stomata.mm2 SD= 17.3). Our results confirm that stomatal density is inversely related to leaf area (r= -0.29, P < 0.001), especially leaf width (r= -0.31, P < 0.001), and that salinity may increase stomatal density by causing reduction of leaf size.

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Dispersal of Goeppertia marantifolia clonal offspring increases with greater canopy openness and larger plant size

Journal of Tropical Ecology ◽

10.1017/s0266467417000013 ◽

2017 ◽

Vol 33 (2) ◽

pp. 107-113 ◽

Cited By ~ 1

Author(s):

David P. Matlaga ◽

Rachel K. Snyder ◽

Carol C. Horvitz

Keyword(s):

Leaf Area ◽

Light Availability ◽

Plant Size ◽

Dispersal Distance ◽

Permanent Plots ◽

Canopy Openness ◽

Parent Plant ◽

Analysis Model ◽

Corcovado National Park ◽

Positive Effect

Abstract:Many plants within the neotropical understorey produce both seeds and clonal offspring. Plant attributes (i.e. size) and variability in light can influence seed dispersal but it is not known if these factors influence the dispersal of clonal offspring. Our goal was to determine if canopy openness and plant size influence clonal-offspring dispersal of the herb Goeppertia marantifolia, which produces clonal bulbils on above-ground shoots. We monitored plants in permanent plots with varying levels of canopy openness in Corcovado National Park, Costa Rica. We recorded canopy openness, leaf area and the distance clonal offspring travelled from their parent plant (N = 283). Our path analysis model demonstrated that canopy openness had a strong positive effect on dispersal distance, while the association between clonal-offspring dispersal distance and parent plant leaf area was only weakly positive. On average, plants experiencing high canopy openness dispersed their clonal offspring further than plants under low canopy openness (124 cm vs. 79 cm, respectively). Contrary to studies on species that utilize rhizomes and stolons for clonal reproduction, we found that in this bulbil-producing species light availability is positively associated with clonal dispersal distance. Therefore, the influence of resource availability on spatial population dynamics of clonal species may be influenced by the species’ growth-form.

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Fitness dependence preserves selection for recombination across diverse mixed mating strategies

Journal of Theoretical Biology ◽

10.1016/j.jtbi.2021.110849 ◽

2021 ◽

pp. 110849

Author(s):

Sviatoslav Rybnikov ◽

Daniel B. Weissman ◽

Sariel Hübner ◽

Abraham B. Korol

Keyword(s):

Mating Strategies ◽

Mixed Mating ◽

Selection For ◽

Fitness Dependence

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Effects of environmental conditions associated to the cardinal orientation on the reproductive phenology of the cerrado savanna tree Xylopia aromatica (Annonaceae)

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652011005000014 ◽

2011 ◽

Vol 83 (3) ◽

pp. 1007-1020 ◽

Cited By ~ 28

Author(s):

Maria Gabriela G. Camargo ◽

Regina M. Souza ◽

Paula Reys ◽

Leonor P.C. Morellato

Keyword(s):

Edge Effects ◽

Environmental Conditions ◽

Fruit Production ◽

Sensu Stricto ◽

Southeastern Brazil ◽

Reproductive Phenology ◽

Canopy Openness ◽

Cerrado Savanna ◽

Cardinal Direction ◽

Floral Visitation

The Brazilian cerrado has undergone an intense process of fragmentation, which leads to an increase in the number of remnants exposed to edge effects and associated changes on environmental conditions that may affect the phenology of plants. This study aimed to verify whether the reproductive phenology of Xylopia aromatica (Lam.) Mart. (Annonaceae) differs under different light conditions in a cerrado sensu stricto (a woody savanna) of southeastern Brazil. We compared the reproductive phenology of X. aromatica trees distributed on east and south cardinal faces of the cerrado during monthly observations, from January 2005 to December 2008. The east face had a higher light incidence, higher temperatures and canopy openness in relation to south face. X. aromatica showed seasonal reproduction at both faces of the cerrado, but the percentage of individuals, the synchrony and duration of phenophases were higher at the east face. The study demonstrated the influence of the environmental conditions associated to the cardinal orientation of the cerrado faces on the phenological pattern of X. aromatica. Similar responses may be observed for other species, ultimately affecting patterns of floral visitation and fruit production, which reinforces the importance of considering the cardinal direction in studies of edge effects and fragmentation.

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Mixed mating strategies in cooperatively breeding apostlebirds Struthidea cinerea

Journal of Avian Biology ◽

10.1111/j.0908-8857.2008.04102.x ◽

2008 ◽

Vol 39 (1) ◽

pp. 50-56 ◽

Cited By ~ 9

Author(s):

Iain A. Woxvold ◽

Raoul A. Mulder

Keyword(s):

Mating Strategies ◽

Mixed Mating ◽

Cooperatively Breeding ◽

Struthidea Cinerea

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Size-dependent allocation of biomass to ancillary versus flowers of the inflorescences of the epiphyte Tillandsia stricta Soland (Bromeliaceae)

Acta Botanica Brasilica ◽

10.1590/s0102-33062009000100016 ◽

2009 ◽

Vol 23 (1) ◽

pp. 130-135 ◽

Cited By ~ 4

Author(s):

André Mantovani ◽

Ricardo Rios Iglesias

Keyword(s):

Leaf Area ◽

Plant Species ◽

Vegetative Growth ◽

Reproductive Investment ◽

Plant Size ◽

Reproductive Allocation ◽

Heterogeneous Environment ◽

Plant Resources ◽

Total Leaf Area ◽

Size Dependent

The amount of resources invested in reproduction is closely correlated to plant size. However, the increase in reproductive investment is not always proportional to the increase in vegetative growth, as the proportion of plant resources allocated to reproduction can increase, decrease or be maintained along different plant sizes. Although comprising thousand of species, epiphytes are poorly studied in relation to reproductive allocation (RA). We describe the variation in the RA of the epiphytic bromeliad Tillandsia stricta Soland with increasing plant sizes. Our goal is not only to evaluate the RA of the whole inflorescence but also quantify the contribution of ancillary structures in the final RA of this plant species. With increasing sizes of T. stricta the reproductive allocation of biomass to the whole inflorescence decreased significantly along plant sizes from 37% to 12%. Reproductive allocation to ancillary and to flowers decreased respectively from 30% to 9% and 10% to 3%. As leaves are the main source of water and nutrients absorption in atmospheric Tillandsia, the total leaf area and area per leaf were used as indicators of foraging capacity, that also increased with plant size. We discuss these results with respect to the capacity of T. stricta to reproduce in the heterogeneous environment of the canopies.

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Soft-Computing-Based Approaches for Plant Leaf Disease Detection

Advances in Environmental Engineering and Green Technologies - Applications of Image Processing and Soft Computing Systems in Agriculture ◽

10.4018/978-1-5225-8027-0.ch004 ◽

2019 ◽

pp. 100-113

Author(s):

Vivek K. Verma ◽

Tarun Jain

Keyword(s):

Image Processing ◽

Leaf Area ◽

Soft Computing ◽

Environmental Conditions ◽

The Other ◽

Disease Detection ◽

Plant Leaves ◽

Plant Leaf ◽

Disease Occurrence ◽

Plant Image

The disease occurrence phenomena in plants are season-based which is dependent on the presence of the pathogen, crops, environmental conditions, and varieties grown. Some plant varieties are particularly subject to outbreaks of diseases; on the other hand, some are opposite to them. Huge numbers of diseases are seen on the plant leaves and stems. Diseases management is a challenging task. Generally, diseases are seen on the leaves or stems of the plant. Image processing is the best way for the detection of plant leaf diseases. Different kinds of diseases occur because of the attack of bacteria, fungi, and viruses. The monitoring of leaf area is an important tool in studying physiological capabilities associated with plant boom. Plant disorder is usually an unusual growth or dysfunction of a plant. Sometimes diseases damage the leaves of plants.

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