The relationship of reproductive biology to the rarity of endemic Aster curtus (Asteraceae)

1999 ◽  
Vol 77 (1) ◽  
pp. 140-149 ◽  
Author(s):  
David E Giblin ◽  
Clement W Hamilton
Keyword(s):  
Pacific Northwest ◽  
Reproductive Biology ◽  
Fluorescent Microscopy ◽  
Pollen Grains ◽  
Field Trials ◽  
Rare Plants ◽  
Glacial Outwash ◽  
Compatible Cross ◽  
Species Rarity ◽  
Filled Seeds

The fecundity of rare plants is a commonly used indicator of performance at the population or species level. However, accurately interpreting reproductive output requires an understanding of a particular species's breeding system. The purpose of this study was to determine if reproductive biology contributes to the restricted distribution of Aster curtus Cronq. We hypothesized that (i) A. curtus, like many Asteraceae species, is self-incompatible, and (ii) that pollinations between patches produce significantly more filled seeds than pollinations within patches. Fluorescent microscopy of pistils harvested after greenhouse pollination showed A. curtus to be partially self-compatible. Cross-pollination resulted in significantly more pollen grains per stigma and significantly greater pollen germination than self-pollination. Similarly, field pollination trials showed that between-patch crosses produced significantly more filled seeds than within-patch crosses. Nevertheless, within-patch pollinations produced substantial levels of filled seed. Results from the greenhouse and field trials suggest that the reproductive biology of A. curtus contributes little to its rarity. Understanding why A. curtus is rare has important implications to the conservation of the glacial outwash prairie. Moreover, the data from this research can be used in further developing predictive models for plant species rarity based on reproductive biology.Key words: Aster, endemic, Pacific Northwest, rarity, reproductive biology, self-incompatibility.

Forensic palynology and ethnobotany of Salicornia species (Chenopodiaceae) in northwest Canada and Alaska

2005 ◽  
Vol 83 (1) ◽  
pp. 111-123 ◽  
Author(s):  
Petra J Mudie ◽  
Sheila Greer ◽  
Judith Brakel ◽  
James H Dickson ◽  
Clara Schinkel ◽  
...  
Keyword(s):  
First Nations ◽  
Pacific Northwest ◽  
Environmental Scanning Electron Microscopy ◽  
Pollen Grains ◽  
Environmental Scanning ◽  
Saline Soils ◽  
Historical Knowledge ◽  
Ancient People ◽  
Salt Marsh Species ◽  
Stomach Sample

Pollen grains from bodies of ancient people provide clues to their diet and domicile. To learn more about Kwädāy Dän Ts'ìnchí (Long Ago Person Found), who died on a British Columbia glacier 550 years ago, we studied the Chenopodiaceae pollen found in his stomach and robe. Environmental scanning electron microscopy was used to distinguish pollen of the native chenopod genera Atriplex, Chenopodium, Eurotia, Suaeda, and Salicornia (here including Sarcocornia). All chenopod pollen grains in one stomach sample were from Salicornia (Tourn.) L. (glasswort), which grows only in saline soils and has been used for food and medicine. Elders from the Champagne and Aishihik, Tagish, Gwitch'in, and Tlingit First Nations report their ethnobotanical and historical knowledge about inland and coastal Salicornia species. There is no common use for the small inland annual glasswort, Salicornia rubra A. Nelson, although other species were used for grain further south; however, Pacific Northwest coastal people have eaten the succulent perennial glasswort, Salicornia perennis Miller, since at least the 1880s. Pollen grains of this perennial salt marsh species are most similar to the chenopod pollen grains in the stomach of Kwädāy Dän Ts'ìnchí and suggest the ancient man's last meal came from the coast rather than from inland.Key words: Chenopodiaceae, Salicornia, Sarcocornia, forensic palynology, frozen body, ethnobotany.

Impact of dwarf mistletoe on some aspects of the reproductive biology of jack pine

1996 ◽  
Vol 72 (3) ◽  
pp. 303-306 ◽  
Author(s):  
Albert Sproule
Keyword(s):  
Reproductive Biology ◽  
Jack Pine ◽  
Dwarf Mistletoe ◽  
Infection Level ◽  
North Central ◽  
Clear Cutting ◽  
Pine Regeneration ◽  
Pine Trees ◽  
Four Levels ◽  
Filled Seeds

A study was conducted in north-central Alberta to examine the effects of dwarf mistletoe on the reproductive biology of jack pine trees with severe, moderate, light and no infection. Fifty cones were collected from each of six trees in each infection class and from three non-infected trees. Cone counts were 401, 547, 787 and 1217 respectively for the four levels of infection. Total seeds per cone were 17.4, 16.3, 27.9 and 25.7. Filled seeds per cone were 13.0, 10.4, 19.9 and 18.9. Numbers of expected germinants per tree were, correspondingly 4442, 3871, 11827 and 18753. These results could be important for managers depending on natural regeneration to produce fully stocked stands following clear-cutting of infected trees. Key words: dwarf mistletoe, germinants, infection level, Jack pine, regeneration

scholarly journals Reproductive biology and pollination of Cabomba aquatica (Cabombaceae)

Rodriguésia ◽  
2011 ◽  
Vol 62 (4) ◽  
pp. 919-926 ◽  
Author(s):  
Jacilene Bezerra da Silva ◽  
Ana Virgínia de Lima Leite
Keyword(s):  
Reproductive Biology ◽  
High Frequency ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Pollen Flow ◽  
Northeastern Brazil ◽  
Nectar Production ◽  
High Pollen ◽  
Pollinator Behavior ◽  
Effective Pollinators

Abstract Reproductive biology and pollination of the fanwort, Cabomba aquatica Aubl., were studied in populations from dams located in Dois Irmãos State Park, Recife, Pernambuco state, northeastern Brazil. Flower anthesis in this species is diurnal and lasts two days. The flowers are bisexual and exhibit herkogamy and incomplete protogyny. Each flower produces an average of 2.1 ± 94.8 pollen grains, with a P/O ratio of 1.055 and high pollen viability (99.7%). This species is self-compatible, but requires biotic vectors to transfer pollen. We observed visits of bees (Apidae and Halictidae), wasps (Vespidae) and flies (Diptera) to the flowers. Bees and wasps were considered to be effective pollinators, both due to their behavior and their high frequency of visits to flowers, whereas flies were considered to be occasional pollinators. The floral mechanism (herkogamy and protogyny), together with low nectar production and pollinator behavior during visits, may contribute to increase pollen flow between individuals.

scholarly journals On the reproductive biology of Salacia fruticosa Wall. ex M.A. Lawson - an endemic medicinal plant of the Western Ghats, india

2018 ◽  
Vol 10 (15) ◽  
pp. 13002-13005
Author(s):  
K. Subin ◽  
P. A. Jose ◽  
T. V. Sarath
Keyword(s):  
Reproductive Biology ◽  
Fruit Set ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Seedling Bank ◽  
The Poor ◽  
Short Period ◽  
Poor Seed ◽  
Endemic Medicinal Plant ◽  
The Western Ghats

Salacia fruticosa Wall. ex M.A. Lawson, an endemic species was studied for the reproductive biology as this species showed reduced fruit set and natural regeneration.  The stigma-anther proximity, an extremely low number of pollen grains, a short period of pollen viability, a sparse incidence of pollinators, protandrous and facultative autogamous nature of the flowers and a low percent in fruit set were identified as biological constraints for the species.  The incidence of seed pest was added to the poor seed and seedling bank and accelerated rarity process of the species.

scholarly journals Reproductive biology in monoecious and gynoecious cucumber cultivars as a result of IBA application

2008 ◽  
Vol 26 (1) ◽  
pp. 30-34
Author(s):  
Valdir Diola ◽  
Afonso I Orth ◽  
Miguel P Guerra
Keyword(s):  
Cucumis Sativus ◽  
Reproductive Biology ◽  
Linear Response ◽  
Pollen Grains ◽  
Sexual Expression ◽  
Seed Number ◽  
General Aspect ◽  
Yield And Quality ◽  
Male Flowers ◽  
Female Flowers

The understanding of both the reproductive biology and the regulation of the sexual expression of cucumber flowers (Cucumis sativus) makes crop management easier and can improve fruit yield and quality. The objective of this study was to evaluate the physiological answer of cucumber floral verticils to the application of IBA. The experiment was carried out in a greenhouse, in completely randomized blocks, with four replications of 4-plant plots, and treatments applied to a 5 x 2 factorial (0, 50, 100, 200, and 500 µmol of IBA, and two cultivars: Wisconsin MR28, gynoecious, and Caipira, monoecious). Cultivar Wisconsin MR28 produced in average 7,636 pollen grains (PG) per flower, with a positive linear response to the increase in IBA concentration. Instead, in cultivar Caipira (5,160 PG) all IBA concentrations reduced PG production. Cultivars did not differ from each other in relation to PG viability (average in vitrogermination of 75.4 and 79.9% to cultivars Wisconsin MR28 and Caipira, respectively) and in both PG viability increased linearly with the increase in AIB concentration. Cultivars Wisconsin MR28 and Caipira presented in average 71.6 and 70.6 seeds per fruit respectively, and responded with an increase in seed number and improvement in fruit general aspect to the rise in IBA concentration. The ratio male:female flowers was significantly different between cultivars (4.2:1 and 3.5:1, respectively to cultivars Wisconsin MR28 and Caipira) and responded in a distinct way to IBA concentrations. While in cultivar Caipira, IBA concentrations near to 100 µmol increased the number of male flowers; in cultivar Wisconsin MR28 the same IBA concentration reduced it. The two cultivars had a similar number of female flowers. However, whereas it remained relatively stable in cultivar Caipira in spite of the increase in IBA concentration, there was an increase in the number of female flowers in cultivar Wisconsin MR28, as a result of the rise in IBA concentration.

Reproductive biology of Ophiopogon xylorrhizus (Liliaceae s.l.): an endangered endemic of Yunnan, Southwest China

2000 ◽  
Vol 48 (1) ◽  
pp. 101 ◽  
Author(s):  
Tian-hua He ◽  
Guang-yuan Rao ◽  
Rui-lin You
Keyword(s):  
Reproductive Biology ◽  
Southwest China ◽  
Airborne Pollen ◽  
In Situ Conservation ◽  
Pollen Grains ◽  
Single Species ◽  
Developmental Phase ◽  
Germinated Pollen ◽  
Mature Seeds

Reproductive biology of Ophiopogon xylorrhizus Wang et Tai was studied from 1995 to 1997 in Mengla County of Yunnan Province, Southwest China. The small, white or pale pink flowers with stigmas above anthers appeared from late March to early April in the study years, and produced abundant pollen, but no nectar. Pollen : ovule ratios were 17 185 ± 2175. Every flower opens only once and remains functional for 10–12 h. Pollen remains viable for the same period. During anthesis, flowers were visited only by single species of thrips (Taeniothrips sp., Thripidae). No airborne pollen grains were collected throughout the blooming season, indicating that flowers are not wind-pollinated. About 28% of stigmas of unopened flowers were found with germinated pollen grains and seed set took place in single flowers that were bagged at the bud stage, which indicated autogamy and autonomous self-pollination. Ovary walls ruptured 4–5 days after fertilisation, allowing seed production to occur. About 75% of ovules were fertilised and developed into young seeds, but only 12.5% developed into mature seeds in open pollination treatments. The remainder of ovules were aborted or destroyed by insects or animals during the long developmental phase from April to December. Individuals of O. xylorrhizus commonly produced a single inflorescence with 2–24 flowers (15.3 ± 6.5, n = 33), and 1–43 seeds (12.7 ± 6.7, n = 33) during the study period. Conservation management for this endangered species is urgently required and in situ conservation is probably the best method to conserve this species.

Wetland management and conservation of rare species

1995 ◽  
Vol 73 (7) ◽  
pp. 1019-1028 ◽  
Author(s):  
Lesley Lovett Doust ◽  
Jon Lovett Doust
Keyword(s):  
Rare Species ◽  
Wetland Management ◽  
Species Conservation ◽  
Economic Incentives ◽  
Rare Plants ◽  
Habitat Conservation ◽  
Multiple Use ◽  
Ethical Decisions ◽  
Management Plans ◽  
Species Rarity

The value of wetland is now widely recognized; some legislation requires "no net loss" of wetlands, although economic incentives still exist for wetland conversion. Rare plants may be protected by law; however, wetlands are rarely managed specifically to conserve rare species. Furthermore, it is not always clear how the environment should be manipulated to increase the abundance of such species, since necessary autecological details are rarely available. Species conservation involves demographic and genetic elements, as well as ethical decisions about the merits of transplanting or importing genes through controlled pollinations. Rare species may serve as indicators of habitat quality, although this will depend on the reasons behind the species' rarity. There is a need for multiple-use management plans that incorporate species- and habitat-conservation goals and that implement overall strategies to maintain or enhance the total quantity and quality of wetlands. Key words: rare plants, management, wetland conservation, habitat conservation.

Efficacy of Several Herbicides on Yellow Archangel (Lamiastrum galeobdolon)

2014 ◽  
Vol 7 (2) ◽  
pp. 269-277
Author(s):  
Timothy W. Miller ◽  
Alison D. Halpern ◽  
Frances Lucero ◽  
Sasha H. Shaw
Keyword(s):  
Pacific Northwest ◽  
Good Control ◽  
Relative Sensitivity ◽  
Field Trials ◽  
Effective Control ◽  
Clove Oil ◽  
Greenhouse Trial ◽  
The Pacific ◽  
Lamiastrum Galeobdolon ◽  
Forest Floor Vegetation

AbstractYellow archangel is a twining perennial species that produces a dense evergreen canopy and may negatively affect forest floor vegetation. Because it is spreading rapidly in the Pacific Northwest (PNW), greenhouse and field trials were conducted on yellow archangel to determine its relative sensitivity to several herbicides. Products that slowed or prevented yellow archangel regrowth at 9 mo after treatment (MAT) in one or both iterations of the greenhouse trial were aminopyralid, diclobenil, glufosinate, imazapyr, isoxaben, metsulfuron, sulfometuron, triclopyr amine, and triclopyr ester + 2,4-D ester. In the field trial at 10 MAT, triclopyr and imazapyr were controlling 81 and 78% of treated yellow archangel, respectively, similar to aminopyralid, glyphosate, and metsulfuron (61 to 65%). Two applications of 20% acetic acid or 20% clove oil were controlling 53% at the same timing. At 13 MAT, only imazapyr and glyphosate were still providing good control of yellow archangel (81 and 80%, respectively), while all other products were controlling the weed at 53% or less. By 7 or 8 MAT after a second application, only imazapyr and glyphosate provided effective control of yellow archangel (86 to 94%).

scholarly journals Cytogenetics and Reproductive Biology of some BELE (Abelmoschus manihot Linn., Medic Sub-Species manihot) Cultivars

2002 ◽  
Vol 20 (1) ◽  
pp. 4 ◽  
Author(s):  
Anand P. Tyagi
Keyword(s):  
Papua New Guinea ◽  
Reproductive Biology ◽  
Genetic Difference ◽  
Pollen Viability ◽  
Pollen Grains ◽  
New Guinea ◽  
Staining Technique ◽  
Root Tips ◽  
Fiji Islands ◽  
Cross Compatibility

Four locally grown (from Fiji Islands) and three imported (from Papua New Guinea), a total of seven BELE (Abelmoschus manihot Linn., Medic sub-species manihot) cultivars were investigated for their cytogenetics and reproductive biology. Chromosome counting from flower buds and root tips showed that chromosome number in all the seven cultivars does not exceed 2n=66. Pollen viability in all the seven cultivars was high, exceeding 85% from pollen staining technique and 78% from pollen germination technique. All the seven Bele cultivars were fully self-compatible. Cross-compatibility among four local cultivars and three cultivars from Papua New Guinea was very high. However cross compatibility between local (Fijian) cultivars and cultivars from Papua New Guinea was partial indicating some degree of genetic difference between cultivars from two countries. This could be due to differences in compatibility alleles between cultivars from Fiji and Papua New Guinea. Procedures such as cutting the style shorter and placing pollen grains to enhance and affect fertilisation to get cross seed were suggested.

Self-compatibility, autonomous self-pollination, and insect-mediated pollination in the clonal species Iris versicolor

1993 ◽  
Vol 71 (11) ◽  
pp. 1503-1509 ◽  
Author(s):  
Paul Kron ◽  
Steven C. Stewart ◽  
Allison Back
Keyword(s):  
Reproductive Biology ◽  
Fruit Set ◽  
Pollen Grains ◽  
Clonal Plants ◽  
Pollinator Behaviour ◽  
Self Pollination ◽  
Self Compatibility ◽  
Three Stages ◽  
Pass Through ◽  
Clonal Species

In clonal species, sexual and asexual systems interact to create a hierarchy of reproduction. For example, self-pollination can occur within pollination units, flowers, ramets, or clones. We investigated the reproductive biology of a natural population of Iris versicolor using pollination manipulations and observations of pollinator behaviour. We found that (i) individuals were completely self-compatible, (ii) selfing rates were close to 100%, (iii) autonomous self-pollination can occur through stigma–anther contact or wind action, (iv) most seed and fruit set can be accounted for by insect pollination, and (v) facilitated self-pollination likely occurs because pollinators frequently visit more than one pollination unit within a flower. Our observations showed that flowers pass through three stages: (i) a male stage (in which pollen is freely available, but stigmas are inaccessible, preventing autogamy); (ii) a female stage (in which stigma flaps have reflexed and are receptive, but pollinators may have already removed most pollen grains, structuring opportunities for geitonogamy); and (iii) a strongly autogamous stage (in which stigma flaps have curled back to contact anthers, leading to delayed autonomous self-pollination). This hierarchy of relatedness among mates determines the genetic consequences of vegetative and sexual reproduction in clonal plants and influences their evolution. Key words: Iris, self-incompatibility, reproductive biology, clonal, pollination.

Sign in / Sign up

Export Citation Format

Share Document