Causes of infertility in the endangered Australian endemic plant Borya mirabilis (Boryaceae)

2015 ◽  
Vol 63 (7) ◽  
pp. 554 ◽  
Author(s):  
Noushka H. Reiter ◽  
Neville G. Walsh ◽  
Ann C. Lawrie

Borya mirabilis Churchill (Boryaceae, Asparagales) is a herbaceous perennial and one of Australia’s most endangered plants. Only one population of four colonies remains, on a rock ledge in the Grampians (Gariwerd) National Park in Victoria, Australia. The reasons why B. mirabilis flowers freely but does not set seed were investigated. Borya mirabilis had a greater proportion of floral abnormalities than other, fertile Borya species. The pollen was often mis-shapen, with ≤ 1% pollen tube formation, but the ovules showed no structural dissimilarity from other, fertile Borya species. The flowers offered a nectar reward and many insects visited the pollen-bearing flowers in the field. Artificial cross-pollination resulted in the first recorded seed for this species. Borya mirabilis has ~66 chromosomes, relative to the diploid number of ~26 in Borya constricta Churchill, strongly suggesting that B. mirabilis is polyploid. Only 4–7% genetic diversity was found within the remaining B. mirabilis field population using 25/60 RAPD primers that showed heterogeneity. An ex-situ nursery collection was found not to contain all genotypes. Recommendations for the conservation of B. mirabilis include capturing all the known genetic diversity in cloned plants in preference over further attempts to produce seed.

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10521
Author(s):  
Núria Garcia-Jacas ◽  
Jèssica Requena ◽  
Sergi Massó ◽  
Roser Vilatersana ◽  
Cèsar Blanché ◽  
...  

Seseli farrenyi (Apiaceae) is an extremely narrow endemic plant, which is considered as one of the species of most conservation concern in Catalonia (NW Mediterranean Basin). Given the accelerated fragmentation and reduction of population size (of over 90%), the environmental agency of Catalonia is currently preparing a recovery plan that includes reinforcements of the extant populations. The present study is aimed at providing the necessary knowledge to carry out genetically-informed translocations, by using microsatellites as genetic markers. Fourteen microsatellites have been specifically developed for S. farrenyi, of which nine have been used. Besides the extant natural populations, the three ex situ collections that are known to exist of this species have also been studied, as they would be the donor sources for translocation activities. Our main finding is that levels of genetic diversity in the natural populations of S. farrenyi are still high (He = 0.605), most likely as a result of a predominantly outcrossing mating system in combination with the limited time elapsed since the population decline. However, population fragmentation is showing the first genetic signs, as the values of genetic differentiation are relatively high, and two well-differentiated genetic lineages have been found even in such a narrow geographic range. These genetic results provide important information when designing conservation management measures.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1984
Author(s):  
Paulina Bolc ◽  
Bogusław Łapiński ◽  
Wiesław Podyma ◽  
Maja Boczkowska

Avena macrostachya is still a relatively unknown species. Using sequence-related amplified polymorphism (SRAP) markers, a simple and inexpensive technique, allowed us to conduct experiments on genetic differentiation and to study the population structure of this Algerian endemic oat. The results obtained showed lower than expected genetic diversity within the A. macrostachya species. The cause may be endemism of the species as well as genetic drift possible during collection, and maintenance of the accessions in gene bank and seed reproduction. No clear genetic structure was found in the examined collection, which indicates a close relationship between the populations collected in the Djurdjura National Park in Algeria. Considering the endemism of the species, its breeding potential and the small-scale ex situ collection, careful monitoring of natural sites and repeating of the collection mission are, therefore, absolutely crucial.


Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 139
Author(s):  
Marlien M. van der Merwe ◽  
Jia-Yee S. Yap ◽  
Peter D. Wilson ◽  
Helen T. Murphy ◽  
Andrew Ford

Maximising genetic diversity in conservation efforts can help to increase the chances of survival of a species amidst the turbulence of the anthropogenic age. Here, we define the distribution and extent of genomic diversity across the range of the iconic but threatened Acacia purpureopetala, a beautiful sprawling shrub with mauve flowers, restricted to a few disjunct populations in far north Queensland, Australia. Seed production is poor and germination sporadic, but the species occurs in abundance at some field sites. While several thousands of SNP markers were recovered, comparable to other Acacia species, very low levels of heterozygosity and allelic variation suggested inbreeding. Limited dispersal most likely contributed towards the high levels of divergence amongst field sites and, using a generalised dissimilarity modelling framework amongst environmental, spatial and floristic data, spatial distance was found to be the strongest factor explaining the current distribution of genetic diversity. We illustrate how population genomic data can be utilised to design a collecting strategy for a germplasm conservation collection that optimises genetic diversity. For this species, inclusion of all field sites will capture maximum genetic diversity for both in situ and ex situ conservation. Assisted cross pollination, within and between field sites and genetically structured groups, is recommended to enhance heterozygosity particularly at the most disjunct sites and further fragmentation should be discouraged to avoid loss of genetic connectivity.


2014 ◽  
Vol 38 ◽  
pp. 1169-1181 ◽  
Author(s):  
Ertuğrul FİLİZ ◽  
Etem OSMA ◽  
Ali KANDEMİR ◽  
Hüseyin TOMBULOĞLU ◽  
Güzin TOMBULOĞLU ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Annae M. Senkoro ◽  
Pedro Talhinhas ◽  
Fernanda Simões ◽  
Paula Batista-Santos ◽  
Charlie M. Shackleton ◽  
...  

AbstractThe pepper-bark tree (Warburgia salutaris) is one of the most highly valued medicinal plant species worldwide. Native to southern Africa, this species has been extensively harvested for the bark, which is widely used in traditional health practices. Illegal harvesting coupled with habitat degradation has contributed to fragmentation of populations and a severe decline in its distribution. Even though the species is included in the IUCN Red List as Endangered, genetic data that would help conservation efforts and future re-introductions are absent. We therefore developed new molecular markers to understand patterns of genetic diversity, structure, and gene flow of W. salutaris in one of its most important areas of occurrence (Mozambique). In this study, we have shown that, despite fragmentation and overexploitation, this species maintains a relatively high level of genetic diversity supporting the existence of random mating. Two genetic groups were found corresponding to the northern and southern locations. Our study suggests that, if local extinctions occurred in Mozambique, the pepper-bark tree persisted in sufficient numbers to retain a large proportion of genetic diversity. Management plans should concentrate on maintaining this high level of genetic variability through both in and ex-situ conservation actions.


2012 ◽  
Vol 60 (7) ◽  
pp. 582
Author(s):  
Ji Hee Jeong ◽  
Zin-Suh Kim

The amount and distribution of genetic diversity within and between Megaleranthis saniculifolia Ohwi populations were compared between the central and peripheral regions of the species distribution. Allozyme and ISSR markers were used for genetic analysis of six populations from the central region (DY) and five populations from the peripheral region (MJ). Genetic diversity was substantially higher in the DY region than in the MJ region. Relatively uniform homozygote excess at many loci in most populations indicated that M. saniculifolia was influenced by a substantial degree of inbreeding in both regions. The degree of differentiation between populations was remarkably higher in the MJ region than in the DY region. Cluster analysis showed a trend towards separation between regions, although populations in the MJ region exhibited a slightly different trend according to the markers. We conclude that genetic drift has been affecting the populations in the MJ region for a long time, on the basis of their low genetic diversity, high differentiation, U-shaped allele-frequency distribution, and fixation of alleles towards opposing frequencies (1 or 0) among populations. In contrast, the DY region maintained relatively stable populations, although evidence of a recent bottleneck was found in one population. Along with some practical measures for genetic conservation, we present an optimal sample size for ex situ conservation to secure as many common alleles as possible.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Rapheal Wangalwa ◽  
Eunice Apio Olet ◽  
Grace Kagoro-Rugunda ◽  
Casim Umba Tolo ◽  
Patrick E. Ogwang ◽  
...  

Citropsis articulata is a medicinal plant that is increasingly threatened by unsustainable methods of harvesting and habitat degradation. Owing to the fact that this plant species is highly utilized for herbal medicine and is currently restricted to a few forest reserves in Uganda, this has significant implications for ex situ conservation. Therefore, the aim of this study was to assess how physiographical factors influence the occurrence and distribution of C. articulata in the three forest reserves in Uganda, namely, Budongo, Mabira, and Kibale National Park. The study was carried out in 15 compartmental sites in each of the three forests. In each compartmental site, 4 plots of 60 m × 60 m were systematically established, and within each plot, 4 subplots each of size 20 m × 20 m were randomly setup. A total of 240 subplots were assessed for occurrence of Citropsis articulata in each forest. The results indicated a significant ( p < 0.05 ) variation in the density of C. articulata with the highest recorded in Kibale National Park. Citropsis articulata generally occurred at moderate altitudinal landscapes (overall elevation = 1200.0 ± 20.73 m) with soils that are moderately acidic (overall pH = 5.7 ± 0.10), low in salinity (overall salinity = 84.0 ± 3.84 mg/l), and moderate levels of macro- and micronutrients. Citropsis articulata was generally associated with plant communities dominated by canopy tree species of genera such as Chryosphyllum, Celtis, Markhamia, Cynometra, Lasiodiscus, Trilepisium, Funtumia, and Diospyros, thus suggesting that C. articulata is a shade-tolerant species. Establishing the ecological requirements of this plant species among other things informs the potential for ex situ production of this plant. This will not only provide alternative sources of plant harvest but also go a long way in relieving the current harvest pressures exerted on the conserved wild populations of this plant species.


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