Reproductive success in a reintroduced population of a critically endangered shrub, Symonanthus bancroftii (Solanaceae)

2007 ◽  
Vol 55 (4) ◽  
pp. 425 ◽  
Author(s):  
Qigang Ye ◽  
Eric Bunn ◽  
Siegfried L. Krauss ◽  
Kingsley W. Dixon

Symonanthus bancroftii is a critically endangered dioecious shrub, with only one male and one female plant known in the wild. Micropropagated, clonal plants of the male and female parents were hand-pollinated. Seed was germinated in sterile culture and a subsequent daughter (F1) seedling was multiplied in vitro. Micropropagated plants of the original parents and daughter were reintroduced to a natural habitat site. We detail the first study of pollination biology and reproductive success in this extremely rare species. Floral morphology, flowering phenology, pollen viability, female receptivity and fruit set of reintroduced plants of S. bancroftii were investigated. Flower viability of S. bancroftii shows a 25-day maximum for male flowers, whereas non-pollinated female flowers remain viable for a maximum of 38 days (female parent) and 41 days (daughter), respectively. Flowering of reintroduced male and female plants overlaps from mid-June to early November. Pollen remained viable for at least 8 days after anther dehiscence. Maximum stigma longevity recorded was 28 days (female parent) and 39 days (daughter) and maximum ovule longevity varied from 13 days (female parent) to 28 days (daughter). The mean percentage of flowers setting fruit was 39 ± 13% for female parent plants and 48 ± 4% for daughter plants. Empirical reproductive success measures for male–daughter crosses generally exceeded those of the original parent crosses. The reproductive success of S. bancroftii so soon after reintroduction of plants is a positive sign indicating that rapid accumulation of a soil seedbank is feasible and is thus an important first step towards successful establishment of self-sustaining populations of this critically endangered species.

2009 ◽  
Vol 58 (1-6) ◽  
pp. 129-138 ◽  
Author(s):  
Shaun Suitor ◽  
B. M. Pott ◽  
M. H. Mcgowen ◽  
D. J. Pilbeam ◽  
P. H. Brown ◽  
...  

Abstract Low and variable capsule and seed set is a major factor limiting seed production in Eucalyptus globulus seed orchards. This study identified the relative contribution of the maternal and paternal parent to reproductive success in E. globulus, and examined the genetic basis to the observed variation. Reproductive success was measured in terms of the number of viable seeds obtained per flower crossed. Data on the reproductive success of numerous genotypes from the Furneaux, Strzelecki Ranges and Otways races were obtained from: (i) 12 years of operational full-sib crossing; (ii) a designed fullsib diallel mating scheme; and (iii) capsule retention trials conducted over three seasons at two Tasmanian seed orchards on the same ramets of different genotypes. Analysis of the sparse operational data revealed that both male and female factors significantly affected reproductive success, accounting for 5.0% and 7.9% of the variation respectively. The more precise diallel crossing revealed that a large, and significant, proportion 55%, of the variation in reproductive success between crosses at a single site was explained by the female parent. The male parent explained only 6.7%, but this effect was not statistically significant and was related to variation in in vitro pollen germination. The significant female effect was found to be consistent at the genotype level across seasons, sites and pollination techniques suggesting a genetic basis to the variation. It is argued that selection of genetically fecund females is a key consideration in reducing costs of manual pollination for breeding and deployment purposes.


2017 ◽  
Vol 6 (06) ◽  
pp. 1630
Author(s):  
Amalaurpava Mary Michael* ◽  
Gopal G.V.

Climate change may influence the composition of plant communities by affecting the reproduction, growth, establishment and local extinction of plant species. Predicting the effect of climate change may provide insight into the impact and relationship between weather pattern and flowering phenology in long term studies. Pollen viability is one important factor of reproduction. Pollen viability is essential for a good fruit set. The study is undertaken to evaluate the influence of temperature and rainfall fluctuation pattern on floral phenology and pollen viability in the restricted distribution of the plant Ehretia pubescens Benth. Field observation on floral phenology has revealed changes occurring in the pollen viability with the change of temperature and rainfall. The plants show drought resistant; however, it is observed that it blooms immediately after the rainfall. Change in the rainfall pattern results in change in flowering pattern. On the natural habitat fruit set is a good indicating of good germinability of pollen grain in vivo. In vitro pollen germinability is less efficient for this species as supported by the data.


1976 ◽  
Vol 66 (4) ◽  
pp. 731-744 ◽  
Author(s):  
G. A. Vale ◽  
J. W. Hargrove ◽  
A. M. Jordan ◽  
P. A. Langley ◽  
A. R. Mews

AbstractMale and female Glossina morsitans morsitans Westw. which emerged from puparia produced by animal-fed and in vitro-fed colonies in England were marked distinctively with non-toxic paint and released into a natural habitat of G. morsitans and G. pallidipes Aust. in Rhodesia. Concurrently, adults of both species which emerged from locally-collected puparia were marked and released. Recaptures from artificial refuges, odour attractants and mobile baits at periods up to 59 days after release and at distances up to 1800 m from the release site indicated no clear differences between native G. morsitans and the two laboratory-reared groups in respect of body size, amount of fat present at emergence, survival, dispersal, availability to a range of baits, diet, speed of taking a first meal, wing damage and insemination rate. Although the blood-meal identifications for marked female G. morsitans were similar to those for both sexes of unmarked flies, blood-meals from marked males showed a relatively high proportion of bovid identifications. Unmarked flies caught were generally older than marked catches. The ratio of females to males in unmarked samples (1:1 for G. morsitans, 2:1 for G. pallidipes) was roughly double that in marked catches.


2018 ◽  
Vol 12 (7-8) ◽  
pp. 38-45
Author(s):  
A. N. EFREMOV ◽  
N. V. PLIKINA ◽  
T. ABELI

Rare species are most vulnerable to man-made impacts, due to their biological characteristics or natural resource management. As a rule, the economic impact is associated with the destruction and damage of individual organisms, the destruction or alienation of habitats. Unfortunately, the conservation of habitat integrity is an important protection strategy, which is not always achievable in the implementation of industrial and infrastructural projects. The aim of the publication is to summarize the experience in the field of protection of rare species in the natural habitat (in situ), to evaluate and analyze the possibility of using existing methods in design and survey activities. In this regard, the main methodological approaches to the protection of rare species in the natural habitat (in situ) during the proposed economic activity were reflected. The algorithm suggested by the authors for implementing the in situ project should include a preparatory stage (initial data collection, preliminary risk assessments, technology development, obtaining permitting documentation), the main stage, the content of which is determined by the selected technology and a long monitoring stage, which makes it possible to assess the effectiveness of the taken measures. Among the main risks of in situ technology implementation, the following can be noted: the limited resources of the population that do not allow for the implementation of the procedure without prior reproduction of individuals in situ (in vitro); limited knowledge of the biology of the species; the possibility of invasion; the possibility of crossing for closely related species that сo-exist in the same habitat; social risks and consequences, target species or population may be important for the local population; financial risks during the recovery of the population. The available experience makes it possible to consider the approach to the conservation of rare species in situ as the best available technology that contributes to reducing negative environmental risks.


2021 ◽  
Vol 254 ◽  
pp. 108964
Author(s):  
Karel Douda ◽  
Wendell R. Haag ◽  
Felipe Escobar-Calderón ◽  
Barbora Vodáková ◽  
Martin Reichard ◽  
...  

2021 ◽  
Vol 9 (2) ◽  
pp. 220
Author(s):  
Michele Bertoni Mann ◽  
Janira Prichula ◽  
Ícaro Maia Santos de Castro ◽  
Juliana Mello Severo ◽  
Michelle Abadie ◽  
...  

Melanophryniscus admirabilis (admirable red-belly toad) is a microendemic and critically endangered species found exclusively along 700 m of the Forqueta River, in a fragment of the Atlantic Forest of southern Brazil. One of the greatest concerns regarding the conservation of this species is the extensive use of pesticides in areas surrounding their natural habitat. In recent years, the adaptation and persistence of animal species in human-impacted environments have been associated with microbiota. Therefore, the present study aimed to characterize the oral bacterial community of wild M. admirabilis and to address the question of how this community might contribute to this toad’s adaptation in the anthropogenic environment as well as its general metabolic capabilities. A total of 11 oral samples collected from wild M. admirabilis were characterized and analyzed via high-throughput sequencing. Fragments of the 16S rRNA variable region 4 (V4) were amplified, and sequencing was conducted using an Ion Personal Genome Machine (PGM) System with 316 chips. A total of 181,350 sequences were obtained, resulting in 16 phyla, 34 classes, 39 orders, and 77 families. Proteobacteria dominated (53%) the oral microbiota of toads, followed by Firmicutes (18%), Bacteroidetes (17%), and Actinobacteria (5%). No significant differences in microbial community profile from among the samples were reported, which suggests that the low dietary diversity observed in this population may directly influence the bacterial composition. Inferences of microbiome function were performed using PICRUSt2 software. Important pathways (e.g., xenobiotic degradation pathways for pesticides and aromatic phenolic compounds) were detected, which suggests that the bacterial communities may serve important roles in M. admirabilis health and survival in the anthropogenic environment. Overall, our results have important implications for the conservation and management of this microendemic and critically endangered species.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
John E. Schjenken ◽  
David J. Sharkey ◽  
Ella S. Green ◽  
Hon Yeung Chan ◽  
Ricky A. Matias ◽  
...  

AbstractSeminal fluid factors modulate the female immune response at conception to facilitate embryo implantation and reproductive success. Whether sperm affect this response has not been clear. We evaluated global gene expression by microarray in the mouse uterus after mating with intact or vasectomized males. Intact males induced greater changes in gene transcription, prominently affecting pro-inflammatory cytokine and immune regulatory genes, with TLR4 signaling identified as a top-ranked upstream driver. Recruitment of neutrophils and expansion of peripheral regulatory T cells were elevated by seminal fluid of intact males. In vitro, epididymal sperm induced IL6, CXCL2, and CSF3 in uterine epithelial cells of wild-type, but not Tlr4 null females. Collectively these experiments show that sperm assist in promoting female immune tolerance by eliciting uterine cytokine expression through TLR4-dependent signaling. The findings indicate a biological role for sperm beyond oocyte fertilization, in modulating immune mechanisms involved in female control of reproductive investment.


2006 ◽  
Vol 5 (7) ◽  
pp. 1065-1080 ◽  
Author(s):  
Ping Ren ◽  
Deborah J. Springer ◽  
Melissa J. Behr ◽  
William A. Samsonoff ◽  
Sudha Chaturvedi ◽  
...  

ABSTRACT Cryptococcus gattii is a primary pathogenic yeast, increasingly important in public health, but factors responsible for its host predilection and geographical distribution remain largely unknown. We have characterized C. gattii STE12α to probe its role in biology and pathogenesis because this transcription factor has been linked to virulence in many human and plant pathogenic fungi. A full-length STE12α gene was cloned by colony hybridization and sequenced using primer walk and 3′ rapid amplification of cDNA ends strategies, and a ste12αΔ gene knockout mutant was created by URA5 insertion at the homologous site. A semiquantitative analysis revealed delayed and poor mating in ste12αΔ mutant; this defect was not reversed by exogenous cyclic AMP. C. gattii parent and mutant strains showed robust haploid fruiting. Among putative virulence factors tested, the laccase transcript and enzymatic activity were down regulated in the ste12αΔ mutant, with diminished production of melanin. However, capsule, superoxide dismutase, phospholipase, and urease were unaffected. Similarly, Ste12 deficiency did not cause any auxotrophy, assimilation defects, or sensitivity to a large panel of chemicals and antifungals. The ste12αΔ mutant was markedly attenuated in virulence in both BALB/c and A/Jcr mice models of meningoencephalitis, and it also exhibited significant in vivo growth reduction and was highly susceptible to in vitro killing by human neutrophils (polymorphonuclear leukocytes). In tests designed to simulate the C. gattii natural habitat, the ste12αΔ mutant was poorly pigmented on wood agar prepared from two tree species and showed poor survival and multiplication in wood blocks. Thus, STE12α plays distinct roles in C. gattii morphogenesis, virulence, and ecological fitness.


2017 ◽  
Vol 28 (4) ◽  
pp. 606-619 ◽  
Author(s):  
CAROLINE BLANVILLAIN ◽  
THOMAS GHESTEMME ◽  
TEHANI WITHERS ◽  
MARK O’BRIEN

SummaryWe studied the breeding biology of Tahiti MonarchPomarea nigra, a ‘Critically Endangered’ forest bird endemic to Tahiti (French Polynesia). Nest activity was monitored from 1998 to 2002, and again from 2008 to 2015. During these 12 years, only 2–13 breeding pairs per year produced hatchlings. Egg-laying occurred all year, but usually increased between August and January, peaking around November. Of the 200 nests monitored, 33 (16%) were abandoned shortly after construction, 71 had an egg laid immediately after the nest were completed (34 %) and 96 nests (46 %) had a pre-incubation phase of 18.9 ± 1.9 days (3–62 days;n= 47 nests), during which the birds visited the nest on an irregular basis. Half (49 of 96) of these nests were abandoned before an egg was laid, with incubation subsequently commencing at the remaining nests (n= 47). Although both sexes incubated for an average of 13.6 ± 0.3 days (range 13–15), the female usually spent more time incubating than the male. Only one young per nest was ever observed. The average nestling phase was 15.5 ± 0.7 days (range 13 to 20 days). Parents continue to feed the young after fledging for 74 ± 4.7 days (range 42–174). As with many tropical island endemics, the Tahiti Monarch has low reproductive productivity as indicated by the fact that: 1) only 56% of pairs attempt to lay an egg in any one year, 2) most pairs attempt only one brood per year and 3) the considerable length of the nesting and fledging phases. Because of its low productivity, maximising the reproductive success of the Tahiti Monarch is essential to secure its recovery.


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