Ovule pre-emption and pollen limitation in a self-fertile perennial herb (Blandfordia grandiflora, Liliaceae)

Oecologia ◽  
1995 ◽  
Vol 103 (1) ◽  
pp. 101-108 ◽  
Author(s):  
M. Ramsey
Keyword(s):  
Pollen Limitation ◽  
Perennial Herb ◽  
Blandfordia Grandiflora

Flowering of Blandfordia grandiflora (Christmas bells) in response to fire frequency and temperature

2020 ◽  
Vol 68 (6) ◽  
pp. 449
Author(s):  
Stephen J. Griffith ◽  
Susan Rutherford
Keyword(s):  
Survival Rates ◽  
Fire Frequency ◽  
Perennial Herb ◽  
Fire Season ◽  
Frequency Effect ◽  
High Survival ◽  
Flowering Response ◽  
Flowering Season ◽  
Eastern Australia ◽  
Blandfordia Grandiflora

Blandfordia grandiflora (Blandfordiaceae) is a resprouting perennial herb in wet heathland of coastal and tableland habitats on mainland eastern Australia. It has attractive turbinate flowers of considerable horticultural value. Blandfordia grandiflora is reported to have an enhanced flowering response in the first post-fire flowering season, and management prescriptions advocate frequent fire as beneficial for the species. Nonetheless, the present study appears to be the first to document the flowering response and fate of individual plants exposed to a range of fire frequencies (3-, 6- and 9-year intervals) over an extended period. We also examined the flowering response in unburnt habitat. High survival rates (>95%) were observed for B. grandiflora plants in heathland that had remained unburnt for a minimum of 30 years. Flowering after experimental burns was found to peak in the second post-fire flowering season rather than the first, and there was no clear fire frequency effect. Maximum levels of flowering during the second post-fire season reached 38 to 56% of individuals, although in some years post-fire flowering during this peak season was as low as 23%. Comparatively few plants flowered during the second-year peak season after every fire, and ~34% of individuals in both the 6- and 9-year burn treatments failed to flower at any time. Inter-fire flowering was also observed, and in some instances this flowering was not significantly different to the level achieved during the peak post-fire flowering season. For example, ~9% of individuals flowered 5–7 times over a 12-year period despite being burnt on only four occasions. Flowering after vernalisation (winter-chilling) was observed in unburnt heathland, and the level of this response was not significantly different to peak post-fire flowering in some years. The findings are examined in the context of evolutionary and habitat processes within a climate change framework. Future studies should focus on the complex interactions between climate, fire and soil for not only B. grandiflora, but more importantly for the diverse assemblage of plant species in wet heathland.

Limitations on reproduction in alpine Ranunculus acris

1997 ◽  
Vol 75 (1) ◽  
pp. 137-144 ◽  
Author(s):  
Ørjan Totland
Keyword(s):  
Seed Production ◽  
Resource Availability ◽  
Seed Weight ◽  
Pollen Limitation ◽  
Resource Limitation ◽  
Limiting Factors ◽  
Perennial Herb ◽  
Plant Variation ◽  
Hand Pollination ◽  
Ranunculus Acris

This study examines experimentally the influence of limiting factors on seed to ovule ratio and seed weight in three alpine populations of the perennial herb Ranunculus acris L. at Finse, southwest Norway. To test for pollen and resource limitation, seed production of supplementally pollinated or completely defoliated plants was compared to that of untreated plants. In one population the experiment was repeated twice during the season. In mid-season, supplemental hand-pollination had no significant effect on seed to ovule ratio, but significantly increased the seed weight, whereas complete defoliation resulted in a significant decrease in seed to ovule ratio and a marginally significant decrease in seed weight. These results indicate that pollen limitation occurred on seed weight and resource limitation mainly on seed to ovule ratio. Seed production in late-flowering control and defoliated plants in one population was nearly completely absent, whereas supplemental pollination increased seed production substantially. Most seeds were produced at the lowest elevation, and frost damage on developing seeds was most pronounced at the highest elevation population, suggesting that severe weather conditions at the highest altitudes had a negative influence on reproductive processes. Significant positive relationships between seed number and seed weight were found, possibly reflecting a large among-plant variation in total resource availability. Key words: altitude gradient, climate, defoliation, pollen and resource availability, seasonal variation, seed size.

Momordica balsamina L.: An Appraisal on Morphology, Ecological Diversity, Phytochemistry, Pharmacological and Biotechnological Applications

2020 ◽  
Vol 06 ◽  
Author(s):  
Saheed Sabiu ◽  
Christiana Eleojo Aruwa ◽  
Viresh Mohanlall ◽  
Himansu Baijnath
Keyword(s):  
Relevant Information ◽  
Perennial Herb ◽  
Biotechnological Applications ◽  
Tropical Regions ◽  
Toxicological Data ◽  
Human Disorders ◽  
Potential Applications ◽  
Baseline Information ◽  
The Caribbean ◽  
Bioactive Agents

Background: Momordica balsamina L. is a monoecious climbing vine and perennial herb native to the tropical regions of Asia, Arabia and the Caribbean, and with prominent presence in Nigeria, Botswana, Namibia, Swaziland and Southern African provinces. While evidence of its anecdotal usage as medicine exist, scientific reports complementing the claims are still emerging or at their infancy. Objective: This review appraised the morphology, therapeutic and biotechnological significance of M. balsamina. Method: Online resources such as Google Scholar, PubMed, ScienceDirect and MeSH were utilized for literature search and included relevant information from inception till May 2020 to streamline sought outcomes for in-depth discussion. Results: The data gathered and considered worthy of inclusion in this study revealed that M. balsamina is rich in phytonutrients of medicinal significance with cucurbitane-type triterpenoids, balsamin and momordins well characterized and fully elucidated. These compounds and other novel bioactive agents in M. balsamina have found remarkable pharmacological relevance and could further be harnessed for use against several debilitating human disorders. Conclusion: The potential applications of M. balsamina as nutraceutical and pharmaceutical agent should not be undermined. Also, with the inadequate toxicological data on this wild species, its consumption should be with caution and translational studies that could advance scientific knowledge and aid better understanding of both its pharmacokinetics and pharmacodynamics without sidelining its potent biotechnological applications are highly encouraged. It is hoped that this paper will provide baseline information that could serve as a guide and inspiration for further studies on the prospects of M. balsamina.

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