scholarly journals Reasons for the Extremely Small Population of putative hybrid Sonneratia × hainanensis W.C. Ko (Lythraceae)

Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 526 ◽  
Author(s):  
Mengwen Zhang ◽  
Xiaobo Yang ◽  
Wenxing Long ◽  
Donghai Li ◽  
Xiaobo Lv
Keyword(s):  
Seed Germination ◽  
Fiddler Crab ◽  
Pollen Limitation ◽  
Small Population ◽  
Wild Plant ◽  
Putative Hybrid ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Optimal Salinity ◽  
Artificial Pollination

Sonneratia × hainanensis, a species once endemic to Hainan Island in China, is now endangered. China’s State Forestry Administration lists this species as a wild plant species with an extremely small population. Field fixed-point investigations, artificial pollination, and laboratory experiments, as well as other methods, were applied to study the reproductive system and seed germination of S. × hainanensis to elucidate the reasons for the endangerment of this species. The results are as follows: (1) Outcrossing index, pollen-ovule ratio, and artificial pollination showed S. × hainanensis has a mixed mating system and mainly focuses on outcrossing with some self-compatibility. (2) Fruit and seed placement tests showed that the fruit predators on the ground were mainly Fiddler crab and squirrel, with the predation rates being 100%. The artificially spread seeds do not germinate under natural conditions. The mean seed destruction rate and remaining rate of were 82.5% and 17.5%. (3) Seeds need to germinate under ambient light conditions, with an optimal photoperiod of 12 h. Seed germination is extremely sensitive to low temperatures because of optimum temperatures from 30 °C to 40 °C. At an optimal temperature of 35 °C, the seeds germinate under salinities ranging from 0‰ to 7.5‰, with an optimal salinity of 2.5‰, which shows the sensitivity of seed germination to salinity, with low salinity promoting germination, whereas high salinity inhibits germination. These findings indicate that the limited regeneration of S. × hainanensis is caused by the following: (1) Pollen limitation and inbreeding recession caused by the extremely small population of S. × hainanensis. (2) Seeds near parent trees are susceptible not only to high fruit drop rate, but to high predation beneath the parent trees′ canopy as well. (3) Seed germination has weak adaptability to light, temperature, and salinity.

Seed germination in cleistogamous species: theoretical considerations and a literature survey of experimental results

2017 ◽  
Vol 27 (2) ◽  
pp. 84-98 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seed Germination ◽  
Reproductive Success ◽  
Inbreeding Depression ◽  
Seedling Emergence ◽  
Sensu Stricto ◽  
Literature Survey ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Commelina Benghalensis ◽  
Theoretical Considerations

AbstractA cleistogamous species consists of individuals that produce both chasmogamous (open, CH) and cleistogamous (permanently closed, CL) flowers, which facilitates a mixed-mating system. In contrast to what one might expect, CL (obligately selfed) seeds and the plants derived from them can be more fit than CH (potentially outcrossed) seeds and the plants they give rise to. Our aim was to review some theoretical aspects of mixed mating in relation to retention of both CH and CL in cleistogamous species and to determine if data on germination support the notion that CL is advantageous over that of CH. Based on germination (or seedling emergence) of CHvsCL seeds in 29 species in 21 genera and 11 families of monocots and eudicots, CL seeds germinated better in 107 and equally well as in 64 of 252 case studies as CH seeds (67.9%), and the (CH < CL):(CH > CL) ratio was 107/81 (1.32). We conclude that our study lends support to the notion that production of CL seeds by cleistogamous species is advantageous over that of CH seeds. Retention of CH by CL species may be due to the need to prevent complete selfing (s= 1.0) and thus total inbreeding depression (δ), which theory predicts would decrease reproductive success. Some caveats concerning the results of comparative studies on the germination biology of CHvsCL seeds of amphicarpicsensu strictoFabaceae species andCommelina benghalensisand the aerial cleistogamous grassDanthonia spicataare discussed.

scholarly journals Mixed Mating System Are Regulated by Fecundity in Shorea curtisii (Dipterocarpaceae) as Revealed by Comparison under Different Pollen Limited Conditions

PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0123445 ◽  
Author(s):  
Naoki Tani ◽  
Yoshihiko Tsumura ◽  
Keita Fukasawa ◽  
Tomoyuki Kado ◽  
Yuriko Taguchi ◽  
...  
Keyword(s):  
Mating System ◽  
Mixed Mating ◽  
Mixed Mating System

Glyphosate induces transient male sterility in Ipomoea purpurea

Botany ◽  
2008 ◽  
Vol 86 (6) ◽  
pp. 587-594 ◽  
Author(s):  
Regina S. Baucom ◽  
Rodney Mauricio ◽  
Shu-Mei Chang
Keyword(s):  
Male Sterility ◽  
Lethal Dose ◽  
Female Fertility ◽  
Morning Glory ◽  
Response To Treatment ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Ipomoea Purpurea ◽  
Female Function ◽  
Common Effect

Plant death is the most common effect resulting from the application of glyphosate, the active ingredient in the herbicide Roundup®. Individual seedlings of the morning glory, Ipomoea purpurea L. Roth, however, have been shown to exhibit tolerance to glyphosate, surviving after what should have been a lethal dose. Those that grow and reach reproductive maturity often exhibit deformed anthers within what appear to be normally developed flowers. Ipomoea purpurea has a mixed mating system and normally has hermaphroditic flowers that are capable of both selfing and outcrossing. The deformed anthers do not produce pollen, essentially converting a hermaphroditic flower to a female. Here we describe this morphological change and investigate the reproductive consequences of anther deformation. First, there is phenotypic variation for the propensity of an individual to exhibit male sterility through deformed anthers in response to treatment, but a series of field and greenhouse studies suggest that this variation is not genetic. The male sterility is also transient; within an individual, the frequency of flowers with deformed anthers declines over time. Although flowers with deformed anthers do not produce pollen, we observed mixed effects on female function of such flowers. In the greenhouse, flowers with deformed anthers that were hand-pollinated produced as many seeds as flowers with normal anthers, suggesting no effect on female fertility. In the field, however, plants with a higher proportion of anther deformation set significantly fewer seeds than those untreated, suggesting either reduced female fertility, or a reproductive penalty in flowers with deformed anthers due to the inability to self pollinate. Thus, the presence of this trait could alter the selfing to outcrossing ratio in populations that are sprayed with the herbicide. Individuals that exhibited a higher proportion of anther deformation also produce fewer total flowers than untreated plants, suggesting that anther deformation is part of a suite of responses to damage by glyphosate.

scholarly journals Wild sorghum from different eco-geographic regions of Kenya display a mixed mating system

2011 ◽  
Vol 122 (8) ◽  
pp. 1631-1639 ◽  
Author(s):  
Moses M. Muraya ◽  
Evans Mutegi ◽  
Hartwig H. Geiger ◽  
Santie M. de Villiers ◽  
Fabrice Sagnard ◽  
...  
Keyword(s):  
Mating System ◽  
Mixed Mating ◽  
Wild Sorghum ◽  
Mixed Mating System ◽  
Geographic Regions

Herbivory alters the expression of a mixed-mating system

2004 ◽  
Vol 91 (7) ◽  
pp. 1046-1051 ◽  
Author(s):  
Janette A. Steets ◽  
Tia-Lynn Ashman
Keyword(s):  
Mating System ◽  
Mixed Mating ◽  
Mixed Mating System

scholarly journals Variation in reproductive effort, genetic diversity and mating systems across Posidonia australis seagrass meadows in Western Australia

AoB Plants ◽  
2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Elizabeth A Sinclair ◽  
Jane M Edgeloe ◽  
Janet M Anthony ◽  
John Statton ◽  
Martin F Breed ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating System ◽  
Western Australia ◽  
Reproductive Effort ◽  
Genetic Data ◽  
Fruit Production ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Shark Bay ◽  
Range Edge

Abstract Populations at the edges of their geographical range tend to have lower genetic diversity, smaller effective population sizes and limited connectivity relative to centre of range populations. Range edge populations are also likely to be better adapted to more extreme conditions for future survival and resilience in warming environments. However, they may also be most at risk of extinction from changing climate. We compare reproductive and genetic data of the temperate seagrass, Posidonia australis on the west coast of Australia. Measures of reproductive effort (flowering and fruit production and seed to ovule ratios) and estimates of genetic diversity and mating patterns (nuclear microsatellite DNA loci) were used to assess sexual reproduction in northern range edge (low latitude, elevated salinities, Shark Bay World Heritage Site) and centre of range (mid-latitude, oceanic salinity, Perth metropolitan waters) meadows in Western Australia. Flower and fruit production were highly variable among meadows and there was no significant relationship between seed to ovule ratio and clonal diversity. However, Shark Bay meadows were two orders of magnitude less fecund than those in Perth metropolitan waters. Shark Bay meadows were characterized by significantly lower levels of genetic diversity and a mixed mating system relative to meadows in Perth metropolitan waters, which had high genetic diversity and a completely outcrossed mating system. The combination of reproductive and genetic data showed overall lower sexual productivity in Shark Bay meadows relative to Perth metropolitan waters. The mixed mating system is likely driven by a combination of local environmental conditions and pollen limitation. These results indicate that seagrass restoration in Shark Bay may benefit from sourcing plant material from multiple reproductive meadows to increase outcrossed pollen availability and seed production for natural recruitment.

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