Further assessment of pollen limitation in the waratah (Telopea speciosissima)

2000 ◽  
Vol 48 (2) ◽  
pp. 209 ◽  
Author(s):  
Ross L. Goldingay
Keyword(s):  
Vegetative Growth ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Fruit Production ◽  
The Self ◽  
Original Experiment ◽  
Flower Production ◽  
Plant Groups ◽  
Fitness Consequences ◽  
Plant Families

The literature contains much debate about whether pollen limitation results in a cost to plants. A population of the waratah, Telopea speciosissima (Proteaceae), was found to be pollen limited in 1985. The present study examines the consequences and causes of this pollen limitation. In the 2–3 years following the original experiment, there was no difference in vegetative growth, flower production or fruit production between the hand-pollinated or control plants. There was no difference in inflorescence or fruit production between these two plant groups up to 9 years later. There was no cost of the experimental increase in reproduction. Experiments in 1988 failed to reveal further pollen limitation, suggesting that it may only occur in some years in this population. The retention of self-pollen on stigmas after anthesis was implicated as a cause of the original demonstration of pollen limitation because the waratah is self-incompatible, has highly synchronous flowering and, typical of the Proteaceae, deposits self-pollen on its stigmas at anthesis. These traits should provide a continuing influence on fruit set in all years. However, plants did not produce more fruits when the self-pollen was experimentally removed. This suggests that the waratah experiences pollen limitation in years when pollination and nutrient levels are not in equilibrium. Further studies of pollen limitation are required to fully understand the fitness consequences of this phenomenon, and to fully describe its frequency among different plant families and among plants with differing flowering strategies.

The reproductive biology of boreal forest herbs. II. Phenology of flowering and fruiting

1987 ◽  
Vol 65 (10) ◽  
pp. 2047-2056 ◽  
Author(s):  
Kaius Helenurm ◽  
Spencer C. H. Barrett
Keyword(s):  
Boreal Forest ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Fruit Production ◽  
Fruit Removal ◽  
Cornus Canadensis ◽  
Forest Herbs ◽  
Pollinator Service ◽  
Maianthemum Canadense ◽  
Major Factors

The flowering and fruiting phenologies of 12 boreal forest herbs were recorded during 1979 (flowering and fruiting) and 1980 (flowering only) in spruce–fir forests of central New Brunswick. The species studied were Aralia nudicaulis, Chimaphila umbellata, Clintonia borealis, Cornus canadensis, Cypripedium acaule, Linnaea borealis, Maianthemum canadense, Medeola virginiana, Oxalis montana, Pyrola secunda, Trientalis borealis, and Trillium undulatum. Flowering in the community occurred from mid-May to the end of July. The order of flowering was maintained in the 2 years, but the degree of synchronization of inflorescences differed in several species. Fruiting in the community began in mid-July and extended beyond the end of September. The percentage of buds that ultimately bore fruit ranged from 0 (Cypripedium acaule) to 61% (Aralia nudicaulis). With the exception of Cypripedium acaule, which received little pollinator service, the self-incompatible species, Cornus canadensis, Maianthemum canadense, and Medeola virginiana, experienced the lowest levels of fruit-set. Pollen limitation and predation of developing fruit appear to be the major factors limiting percentage fruit-set in boreal forest herbs. Fruit production varied with time of flowering of inflorescences in several species, with periods of low fruit-set tending to coincide with lower densities of flowering inflorescences. Significant rates of fruit removal by herbivores occurred in all sarocochorous species. Disappearance of fruits from infructescences ranged from 31 (Medeola virginiana) to 95% (Aralia nudicaulis), with highest removal rates occurring during periods of greatest fruit availability.

scholarly journals Flowering levels, harvest season and yields of cupuassu (Theobroma grandiflorum)

2011 ◽  
Vol 41 (1) ◽  
pp. 143-152 ◽  
Author(s):  
Giorgini Augusto Venturieri
Keyword(s):  
Fruit Set ◽  
Germplasm Collection ◽  
Fruit Production ◽  
Production Data ◽  
Theobroma Grandiflorum ◽  
Flower Production ◽  
Over Time

Cupuassu (Theobroma grandiflorum), a specie native to Amazonia, has been planted commercially in Brazil to satisfy the demand for the flavorful juice obtained from the pulp around its seeds. The trees are notorious for low and irregular fruit production. Data gathered over two seasons from trees in a germplasm collection in Pará, Brazil, showed that some of them fruited more regularly than others. Differences in fruit production correlated to differences in flower production. Tree-to-tree variation in flower production, fruit production, and consistency of both over time suggest considerable scope for improving yields by selection. Hand pollinations resulted in a much higher frequency of fruit set than open pollinations, indicating that lack of effective pollination is also a reason for low yield. However, attempts to increase the level of effective pollination are handicapped by low knowledge about the pollinators of cupuassu and their behavior.

scholarly journals Direct and Indirect Effects of Overstory Canopy and Sex-Biased Density Dependence on Reproduction in the Dioecious Shrub Shepherdia canadensis (Elaeagnaceae)

Diversity ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 37
Author(s):  
Tyler J. Bateman ◽  
Scott E. Nielsen
Keyword(s):  
Fruit Set ◽  
Plant Density ◽  
Canopy Cover ◽  
Fruit Production ◽  
Pollen Competition ◽  
Density Dependent ◽  
Flower Production ◽  
Male Density ◽  
Focal Female ◽  
Shepherdia Canadensis

This study assessed the reproductive success of a temperate dioecious shrub, Canada buffaloberry, Shepherdia canadensis (L.) Nutt., in central Alberta, Canada, by examining the effects of spatial patterns and overstory canopy on flower and fruit production. S. canadensis is more abundant and productive (more fruit) at forest edges and in forest gaps, suggesting a dependence on higher light conditions than is typical of late-seral forests. We used path analysis to demonstrate that flower and fruit production exhibited density-dependent effects at a scale of 50 m2 around focal female plants. Fruit production was positively affected by male intraspecific density (pollen supply) and negatively affected by female intraspecific density (pollen competition), but not correlated with overall intraspecific density. The effects of sex-differentiated density are partly due to pollinator responses to male plant density. Flower production was positively affected by overall intraspecific density. A pollen supplementation trial doubled fruit production relative to a control, demonstrating that local male density (pollen availability) and pollinator activity can limit fruit production in S. canadensis. Canopy cover was negatively related to both flower and total fruit production, with approximately one-third (34%) of the total effect of canopy on fruit production due to the effect of canopy on flower production. The commonly observed negative association between canopy cover and fruit production in buffaloberry, therefore, is partly a result of the reduction first in flower number and second in fruit set. This study clarifies the mechanisms associated with the often-noted observation, but not previously assessed at the level of individuals, that reproductive output in S. canadensis is density dependent, limited by canopy cover through reductions in both flowering and fruit set, and pollinator limited. These findings hold implications for managing animal species that depend on the fruit of S. canadensis and suggest future directions for research on dioecious and actinorhizal species.

Disentangling the effects of foliar vs. floral herbivory of leaf-cutting ants on the plant reproductive success of Miconia nervosa (Smith) Triana (Family Melastomataceae)

2019 ◽  
Vol 110 (1) ◽  
pp. 77-83
Author(s):  
T. Câmara ◽  
X. Arnan ◽  
V.S. Barbosa ◽  
R. Wirth ◽  
L. Iannuzzi ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Reproductive Organs ◽  
Fruit Production ◽  
Plant Fitness ◽  
Floral Herbivory ◽  
Flower Production ◽  
Plant Reproductive Success ◽  
Leaf Cutting ◽  
Leaf Herbivory

AbstractFlower and leaf herbivory might cause relevant and negative impacts on plant fitness. While flower removal or damage by florivores produces direct negative effects on plant fitness, folivores affect plant fitness by reducing resource allocation to reproduction. In this study, we examine the effects of both flower and leaf herbivory by leaf-cutting ants on the reproductive success of the shrub species Miconia nervosa (Smith) Triana (Family Melastomataceae) in a fragment of Atlantic Forest in Northeast Brazil. We conducted a randomized block-designed field experiment with nine replicates (blocks), in which three plants per block were assigned to one of the three following treatments: undamaged plants (ant exclusion), leaf-damaged plants (ant exclusion from reproductive organs, but not from leaves), and flower + leaf-damaged plants (no exclusion of ants). We then measured flower production, fruit set, and fruit production. Our results showed that flower + leaf-damaged plants reduced flower production nearly twofold in relation to undamaged plants, while flower set in leaf-damaged plants remained constant. The number of flowers that turned into fruits (i.e., fruit set), however, increased by 15% in flower + leaf-damaged plants, while it slightly decreased in leaf-damaged compared to undamaged plants. Contrastingly, fruit production was similar between all treatments. Taken together, our results suggest a prominent role of ant floral herbivory across different stages of the reproductive cycle in M. nervosa, with no consequences on final fruit production. The tolerance of M. nervosa to leaf-cutting ant herbivory might explain its high abundance in human-modified landscapes where leaf-cutting ants are hyper-abundant.

Reproductive Responses of Capsicum annuum to High Temperatures

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 543c-543
Author(s):  
Ami N. Erickson ◽  
Albert H. Markhart
Keyword(s):  
Capsicum Annuum ◽  
High Temperatures ◽  
Fruit Development ◽  
Flower Development ◽  
Fruit Set ◽  
Fruit Production ◽  
Yield Reduction ◽  
Bud Size ◽  
Growth Chambers ◽  
Constant Growth

Fruit yield reduction due to high temperatures has been widely observed in Solanaceous crops. Our past experiments have demonstrated that Capsicum annuum cultivars Ace and Bell Boy completely fail to produce fruit when grown at constant 33 °C. However, flowers are produced, continually. To determine which stages of flower development are sensitive to high temperatures, pepper buds, ranging in size from 1 mm to anthesis, were exposed to high temperatures for 6 hr, 48 hr, 5 days, or for the duration of the experiment. Fruit set for each bud size was determined. Exposure to high temperatures at anthesis and at the 2-mm size stage for 2 or more days significantly reduced fruit production. To determine whether inhibition of pollination, inhibition of fertilization, and/or injury to the female or male structures prevents fruit production at high temperatures, flowers from pepper cultivars Ace and Bell Boy were grown until flowers on the 8th or 9th node were 11 mm in length. Plants were divided between 25 °C and 33 °C constant growth chambers for 2 to 4 days until anthesis. At anthesis, flowers from both treatments were cross-pollinated in all combination, and crosses were equally divided between 33 or 25 °C growth chambers until fruit set or flowers abscised. All flower crosses resulted in 80% to 100% fruit set when post-pollination temperatures were 25 °C. However, post-pollination temperatures of 33 °C significantly reduced fruit production. Reduced fruit set by flowers exposed to high temperatures during anthesis and pollination is not a result of inviable pollen or ovule, but an inhibition of fertilization or initial fruit development.

Pollen limitation and xenia effects in a cultivated mass-flowering tree, Macadamia integrifolia (Proteaceae)

2021 ◽  
Author(s):  
Stephen J Trueman ◽  
Wiebke Kämper ◽  
Joel Nichols ◽  
Steven M Ogbourne ◽  
David Hawkes ◽  
...  
Keyword(s):  
Food Production ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Pollination Services ◽  
Mass Flowering ◽  
Shell Mass ◽  
Cross Pollination ◽  
Macadamia Integrifolia ◽  
Kernel Yield ◽  
Flowering Tree

Abstract Background and Aims Pollen limitation is most prevalent among bee-pollinated plants, self-incompatible plants, and tropical plants. However, we have very little understanding of the extent to which pollen limitation affects fruit set in mass-flowering trees despite tree crops accounting for at least 600 million tons of the 9,200 million tons of annual global food production. Methods We determined the extent of pollen limitation in a bee-pollinated, partially self-incompatible, subtropical tree by hand cross-pollinating the majority of flowers on mass-flowering macadamia (Macadamia integrifolia) trees that produce about 200,000–400,000 flowers. We measured tree yield and kernel quality and estimated final fruit set. We genotyped individual kernels by MassARRAY to determine levels of outcrossing in orchards and assess paternity effects on nut quality. Key Results Macadamia trees were pollen limited. Supplementary cross-pollination increased nut-in-shell yield, kernel yield and fruit set by as much as 97%, 109% and 92%, respectively. The extent of pollen limitation depended upon the proximity of experimental trees to trees of another cultivar because macadamia trees were highly outcrossing. Between 84% and 100% of fruit arose from cross-pollination, even at 200 m (25 rows) from orchard blocks of another cultivar. Large variations in nut-in-shell mass, kernel mass, kernel recovery and kernel oil concentration were related to differences in fruit paternity, including between self-pollinated and cross-pollinated fruit, thus demonstrating pollen-parent effects on fruit quality, i.e. xenia. Conclusions This study is the first to demonstrate pollen limitation in a mass-flowering tree. Improved pollination led to increased kernel yield of 0.31–0.59 tons per hectare, which equates currently to higher farm-gate income of approximately US3,720–US7,080 per hectare. The heavy reliance of macadamia flowers on cross-pollination and the strong xenia effects on kernel mass demonstrate the high value that pollination services can provide to food production.

scholarly journals The effect of using grafted seedlings on the yield and quality of tomatoes grown in greenhouses 

2018 ◽  
Vol 45 (No. 2) ◽  
pp. 76-82 ◽  
Author(s):  
Rodica Soare ◽  
Maria Dinu ◽  
Cristina Babeanu
Keyword(s):  
Fruit Quality ◽  
Vegetative Growth ◽  
Morphological Characteristics ◽  
Fruit Production ◽  
Soluble Solids ◽  
Average Weight ◽  
Appreciable Effect ◽  
Tomato Plants ◽  
Production Characteristics

This study was aimed at observing the effect of the grafting of tomato plants on morphological (vegetative growth), production and nutritive characteristics (quantity and quality of production). For this purpose, the ‘Lorely F1’ cultivar was used as a scion grafted onto the ‘Beaufort’ rootstock. Plants were cultivated with a stem and two stems. The observations collected in this study were concerned with the characteristics of plant growth. The studied morphological characteristics were plant height, stem diameter and number of leaves, and the studied production characteristics were the characteristics of fructification and productivity (the average number of fruit per plant, the average weight of the fruit, production per plant). Particular attention was paid to the nutritional characteristics of the fruit, to the fruit quality (total soluble solids, total sugar, acidity, vitamin C, antioxidant activity (by the Trolox method) and the contents of lycopene and beta-carotene). The results showed that grafting positively influenced the growth and production characteristics. Grafting of tomato plants had an appreciable effect on the vegetative growth of the variant 2-grafted tomatoes with a stem. The best option in terms of productivity and production was the variant 3-grafted tomatoes with two stems, which yielded 9.2 kg per plant. Fruit quality was not improved in any of the grafted variants. 

Plant diversity of Ghorkhod Protected Area, NE Iran

Phytotaxa ◽  
2016 ◽  
Vol 249 (1) ◽  
pp. 118 ◽  
Author(s):  
FARSHID MEMARIANI ◽  
MOHAMMAD REZA JOHARCHI ◽  
HOSSEIN AKHANI
Keyword(s):  
Plant Species ◽  
Protected Area ◽  
Life Form ◽  
Vascular Plant ◽  
Floristic Composition ◽  
Transitional Zone ◽  
Plant Groups ◽  
Wide Range ◽  
Plant Families ◽  
Ne Iran

Ghorkhod Protected Area (GPA) is located in a transitional zone among different biogeographical units in North Khorassan Province, NE Iran. The study area is mainly a mountainous region in western extensions of Khorassan-Kopet Dagh floristic province. We investigated the floristic composition, life form spectrum and phytogeography of the study area through several random collection efforts and 200 vegetation samples (reléves) in selected vegetation types during 2007–2012. A total of 663 vascular plant species belonging to 367 genera and 81 families are recorded as native and naturalized in GPA. Angiosperms and Dicots are among the most diverse plant groups. The richest plant families are Asteraceae (88 species), Poaceae (78), Lamiaceae (45), Brassicaceae (43), Fabaceae (38), and Caryophyllaceae (32). The genera Allium L. (17 species), Astragalus L. (15) and Cousinia Cass. (12) are the richest ones, however, the majority of the species belongs to oligotypic and monotypic genera. Life form spectrum of the study area is dominated by hemicryptophytes (38.9%) and therophytes (23.4%). Allium transvestiens Vved., Agropyron desertorum Schult., Helictotrichon turcomanicum Czopanov and Piptatherum latifolium (Roshev.) Nevski are recorded as new to Iran. The core flora of the area has the Irano-Turanian origin. However, the wide-range and widespread elements are also well represented in the study area. GPA is inhabited by several endemic, rare and narrow-range plant species, indicating the biodiversity importance of the study area in NE Iran.

scholarly journals Carbohidratos y Floración en Hesperaloë funifera (Koch) Trel. (Samandoque)

2017 ◽  
pp. 67
Author(s):  
Steven P. Mclaughlin ◽  
Ryan R. Williams
Keyword(s):  
Fruit Set ◽  
Fruit Production ◽  
Hesperaloe Funifera

Several researchers have noted that flowering in Agavaceae requires substantial resources, but few studies have attempted to directly measure such resources. T his study addresses the hypothesis that fruit set in Hesperaloë funifera is limited by available carbohydrates. The accumulation of total non-structural carbohydrates (TNC) prior to flowering was measured, and total requirements for carbohydrate were estimated. Hesperaloë funifera was found to accumulate fructans, and roots were an important organ for storage of accumulated carbohydrates. Carbohydrates stored in the plant prior to flowering are sufficient to meet only about onethird of the carbohydrate needed to produce an average inflorescence with 1 % to 2% fruit set. All of the carbohydrate produced by photosynthesis from May through August is needed to support flowering and fruit production. Low percentage fruit set in Hesperaloë funifera is probably due to a deficiency of carbohydrate resources.

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