scholarly journals Diversity of root-associated culturable fungi of Cephalanthera rubra (Orchidaceae) in relation to soil characteristics

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8695 ◽  
Author(s):  
Jake Bell ◽  
Kazutomo Yokoya ◽  
Jonathan P. Kendon ◽  
Viswambharan Sarasan

Cephalanthera rubra (L.) Rich., Red Helleborine, is a widespread orchid in Europe but known only from three very small populations in England. These populations are in decline with no natural seed setting for more than a decade. The species may become extinct in the UK soon unless viable strategies are in place for ex situ conservation, especially the use of symbiotic propagation. Because of the fragile nature of the populations in England mycorrhizal fungal diversity study is not feasible. Therefore, to understand the factors needed for healthy Red Helleborine populations, soil characteristics and diversity of culturable root-derived fungi of the populations from a small area in the Loire Valley in France were studied. The main objectives of the study were: (1) Which culturable mycorrhizal fungi associated with C. rubra roots and (2) To what extent is variation in fungal communities related to variation in soil characteristics? Here, we report a significant difference in diversity of culturable mycorrhizal and non-mycorrhizal fungi depending on soil pH and phosphorus content. Mycorrhizal associations were favoured by plants in locations with low soil nutrient availability and comparatively higher pH. Our study shows that mycorrhizal fungi, both ecto and endo, can be cultured from roots of plants at different maturity stages.

Author(s):  
Priyanka Kumari ◽  
R. R. Singh ◽  
Ruby Rani ◽  
Mahendra Singh ◽  
Uday Kumar

Litchi (Litchi chinensis Sonn.) originated from South China, it is sub-tropical evergreen fruit crops, especially grown on the marginal climate of tropics and subtropics. It is delicious juicy fruit of India having excellent nutritional quality, pleasant flavoured, good amount of antioxidant and vitamins C, vitamin B-complex and phytonutrients flavonoids. It has a great potential to earn foreign exchange in the national and international market through export. Arbuscular mycorrhizal (AM) infection is a common association between plant roots and microorganisms. It is responsible for increasing plant nutrient uptake and also increases in macro and micronutrients in leaf. Therefore, the present work has been analyzed macro and micro nutrients from soil and leaf, after 60, 90 and 120 days after inoculation of two bio-inoculants with phosphorus (SSP) including nine treatments with three replications. After 120 days of inoculation both the species of mycorrhizal combination with phosphorus application were very effective. Highest Copper content is (10.99 ppm), Zinc (33.17 ppm), Iron (121.47 ppm) and Manganese (15.33 ppm) was recorded in case T5 (G. mosseae 10 g + Phosphorus 50 mg kg-1 of soil) which is gradually increases. The soil nutrient content gradually decreased with time duration but no- significant difference was found among treatments after 120 days inoculation. After 120 days potting result was found that the Copper content is (1.70 ppm), Zinc (3.07 ppm), Iron (7.80 ppm) and Manganese (4.00 ppm) was recorded in case T5 (G. mosseae 10 g + Phosphorus 50 mg kg-1 of soil).this research was undertaken to find out whether Arbuscular mycorrhizal (AM) infection and phosphorus affect the micro-nutrient status of soil and leaves in nursery stage.


2020 ◽  
Vol 126 (3) ◽  
pp. 345-362 ◽  
Author(s):  
Ryan D Phillips ◽  
Noushka Reiter ◽  
Rod Peakall

Abstract Background Given the exceptional diversity of orchids (26 000+ species), improving strategies for the conservation of orchids will benefit a vast number of taxa. Furthermore, with rapidly increasing numbers of endangered orchids and low success rates in orchid conservation translocation programmes worldwide, it is evident that our progress in understanding the biology of orchids is not yet translating into widespread effective conservation. Scope We highlight unusual aspects of the reproductive biology of orchids that can have important consequences for conservation programmes, such as specialization of pollination systems, low fruit set but high seed production, and the potential for long-distance seed dispersal. Further, we discuss the importance of their reliance on mycorrhizal fungi for germination, including quantifying the incidence of specialized versus generalized mycorrhizal associations in orchids. In light of leading conservation theory and the biology of orchids, we provide recommendations for improving population management and translocation programmes. Conclusions Major gains in orchid conservation can be achieved by incorporating knowledge of ecological interactions, for both generalist and specialist species. For example, habitat management can be tailored to maintain pollinator populations and conservation translocation sites selected based on confirmed availability of pollinators. Similarly, use of efficacious mycorrhizal fungi in propagation will increase the value of ex situ collections and likely increase the success of conservation translocations. Given the low genetic differentiation between populations of many orchids, experimental genetic mixing is an option to increase fitness of small populations, although caution is needed where cytotypes or floral ecotypes are present. Combining demographic data and field experiments will provide knowledge to enhance management and translocation success. Finally, high per-fruit fecundity means that orchids offer powerful but overlooked opportunities to propagate plants for experiments aimed at improving conservation outcomes. Given the predictions of ongoing environmental change, experimental approaches also offer effective ways to build more resilient populations.


2009 ◽  
Vol 57 (4) ◽  
pp. 373 ◽  
Author(s):  
Magali Wright ◽  
Rob Cross ◽  
Kingsley Dixon ◽  
Tien Huynh ◽  
Ann Lawrie ◽  
...  

Many Caladenia species have been reduced to extremely small and/or fragmented populations, and reintroduction/translocation into natural or rehabilitated habitats, by using ex situ propagated plants or via direct seeding, represents an important adjunct in conservation planning. However, Caladenia species are some of the most difficult terrestrial orchid taxa to propagate, in part because of the specificity of the mycorrhizal associations and the need to provide growing conditions that suit both the mycorrhizal fungi and Caladenia plants. The present paper reviews recent advances in Caladenia propagation and reintroduction methods, including in vitro seed germination, transferral from in vitro to nursery environments, ex vitro symbiotic germination (germination in inoculated nursery media), nursery cultivation, the use of nurse plants and reintroduction of Caladenia into natural habitats by using seed, dormant tubers or growing plants. Techniques discussed in the present paper increase the options for future Caladenia conservation programs, especially for those species currently on the brink of extinction.


2000 ◽  
Vol 77 (12) ◽  
pp. 1833-1841 ◽  
Author(s):  
EW van der Heijden ◽  
M Vosatka

Ectomycorrhizal (EcM) and arbuscular mycorrhizal (AM) associations of Salix repens were studied at 16 sites in different successional stages of dune ecosystems (calcareous-acidic, dry-wet) in the Netherlands. High EcM colonization, low AM colonization, and lack of differences between habitats indicate that ectomycorrhizas do not increase their importance in later successional stages. EcM and AM colonization and plant-nutrient status indicate that the relative importance of P and N does not change during succession, but during seasons. Salix repens showed low levels of AM colonization but, nevertheless, even these low levels contributed to covering the P demands of the plant. As a decrease in AM colonization in S. repens at the end of the season coincided with a decrease in AM inoculum potential, the seasonal decline of arbuscular mycorrhiza is caused by changes in plant demand or soil nutrient availability rather than by interference by ectomycorrhiza. Regardless of seasonal shifts and possible interaction between ectomycorrhiza and arbuscular mycorrhiza, both persist in the plant roots during seasons and throughout succession. Differences in the habitat preference of various EcM morphotypes and arbuscular mycorrhiza suggest that mycorrhizal diversity contributes to the broad ecological amplitude of S. repens.


2021 ◽  
Vol 13 (3) ◽  
pp. 10
Author(s):  
P. G. Soti ◽  
Bulent Toprak ◽  
Nina De La Rosa ◽  
Krish Jayachandran

This study was done to assess the effect of soil disturbance on arbuscular mycorrhizal fungi spore abundance and root colonization in avocado (Persea americana Mill.). Rhizosphere soil and root samples of avocado were collected from different farms in south Florida and analyzed for degree of mycorrhizal colonization in roots, spore density and diversity in soil along with soil characteristics. There was significant difference in the soil characteristics among the different farms. Similarly, there was a significant difference in the degree of mycorrhizal colonization in the roots and the arbuscular mycorrhizal fungi spore morphotypes among different land use and management practices. However, there was no significant difference in the total number of arbuscular mycorrhizal fungi spores among these sites. There was no correlation between the number of arbuscular mycorrhizal fungi spores and soil characteristics. However, arbuscular mycorrhizal fungi colonization in roots were strongly influenced by soil characteristics such as soil moisture, carbon, nitrogen, and organic matter. Further research is necessary to identify these AMF species and determine the role of in avocado growth tolerance to anthropogenic disturbance in highly disturbed urban soils.


Science ◽  
2020 ◽  
Vol 367 (6480) ◽  
pp. eaba1223 ◽  
Author(s):  
Leho Tedersoo ◽  
Mohammad Bahram ◽  
Martin Zobel

Mycorrhizal fungi provide plants with a range of benefits, including mineral nutrients and protection from stress and pathogens. Here we synthesize current information about how the presence and type of mycorrhizal association affect plant communities. We argue that mycorrhizal fungi regulate seedling establishment and species coexistence through stabilizing and equalizing mechanisms such as soil nutrient partitioning, feedback to soil antagonists, differential mycorrhizal benefits, and nutrient trade. Mycorrhizal fungi have strong effects on plant population and community biology, with mycorrhizal type–specific effects on seed dispersal, seedling establishment, and soil niche differentiation, as well as interspecific and intraspecific competition and hence plant diversity.


2008 ◽  
Vol 56 (7) ◽  
pp. 609 ◽  
Author(s):  
Karen D. Sommerville ◽  
John P. Siemon ◽  
Chris B. Wood ◽  
Catherine A. Offord

Ex situ conservation of threatened terrestrial orchids requires the simultaneous conservation of their mycorrhizal associations. A method for encapsulating both seed and fungi in alginate beads (known as encapsulation–dehydration) was applied to the storage and propagation of two endangered orchid species in NSW, Australia—Pterostylis saxicola D.L.Jones & M.A.Clem. and Diuris arenaria D.L.Jones. We tested the effect of storage duration and temperature on fungal recovery and germination potential in vitro, and recorded survival for seedlings subsequently transferred to potting mix. Storage at 23°C significantly reduced fungal recovery and germination for both species after only 3 months (P < 0.05), whereas storage at 4°C significantly reduced fungal recovery for P. saxicola after 6 months (P < 0.05). Storage for 6 months at −18 and −196°C had no significant effect on the fungal recovery and germination percentages of either species. All beads transferred directly from in vitro culture to potting mix resulted in the establishment of at least one seedling, and production of a healthy tuberoid, when transferred near the commencement of the natural growing season. The encapsulation–dehydration method may have a practical application for use in ex situ conservation of other terrestrial orchids, as well as their mycorrhizal fungi.


2021 ◽  
Vol 9 (4) ◽  
pp. 792
Author(s):  
Kazutomo Yokoya ◽  
Alison S. Jacob ◽  
Lawrence W. Zettler ◽  
Jonathan P. Kendon ◽  
Manoj Menon ◽  
...  

About 90% of Cynorkis species are endemic to the biodiversity hotspot of Madagascar. This terrestrial habitat-specific genus received little study for fungal diversity to support conservation. We evaluated the diversity of culturable fungi of 11 species and soil characteristics from six sites spanning a >40 km radius in and along the region’s inselbergs. Peloton-forming fungi were grown in vitro from root/protocorm slices and positively identified using DNA sequencing. The fungal diversity was then correlated with soil pH, NO3-N, P, and K. All species harbored either putative mycorrhizal associates in the Rhizoctonia complex or Hypocreales fungi. Tulasnella Operational Taxonomic Units (OTUs) were most prevalent in all soil types while Serendipita OTUs were found in species inhabiting granite/rock outcrops in moist soil (seepage areas). Most Cynorkis species were present in soil with low NO3-N and P levels with diversity of mycorrhizal fungi inversely correlated to NO3-N levels. Of the different orchid life stages sampled, only one species (Cynorkis fastigiata) yielded putative mycorrhizal fungi from juvenile stages. As diversity of mycorrhizal fungi of Cynorkis spp. was negatively correlated with NO3-N, and majority of the studied taxa were found in soils with low NO3-N and P contents, reintroduction studies must include analysis of N and P in detail. For the first time, we showed that the assemblage of culturable fungi in the roots of habitat-specific species of Cynorkis (Orchidaceae) are intimately tied to specific soil characteristics.


2021 ◽  
pp. archdischild-2020-321277
Author(s):  
Matko Marlais ◽  
Kate Martin ◽  
Stephen D Marks

BackgroundThe aim of this study was to investigate whether being on dialysis at the time of renal transplantation affected renal allograft survival in paediatric renal transplant recipients (pRTRs).MethodsRetrospective study of UK Transplant Registry (National Health Service Blood and Transplant) data on all children (aged <18 years) receiving a kidney-only transplant from 1 January 2000 to 31 December 2015. Kaplan-Meier estimates of patient and renal allograft survival calculated and Cox regression modelling accounting for donor type. The relationship between time on dialysis and renal allograft survival was examined.Results2038 pRTRs were analysed: 607 (30%) were pre-emptively transplanted, 789 (39%) and 642 (32%) on peritoneal dialysis and haemodialysis, respectively, at the time of transplantation. Five-year renal allograft survival was significantly better in the pre-emptively transplanted group (90.6%) compared with those on peritoneal dialysis and haemodialysis (86.4% and 85.7%, respectively; p=0.02). After accounting for donor type, there was a significantly lower hazard of 5-year renal allograft failure in pre-emptively transplanted children (HR 0.742, p=0.05). Time spent on dialysis pre-transplant negatively correlated with renal allograft survival (p=0.002). There was no significant difference in 5-year renal allograft survival between children who were on dialysis for less than 6 months and children transplanted pre-emptively (87.5% vs 90.5%, p=0.25).ConclusionsPre-emptively transplanted children have improved 5-year renal allograft survival, compared with children on dialysis at the time of transplantation. Although increased time spent on dialysis correlated with poorer renal allograft survival, there was no evidence that short periods of dialysis pre-transplant affected renal allograft survival.


Author(s):  
Ganesh Vigneswaran ◽  
Drew Maclean ◽  
Mohammed Hadi ◽  
Benjamin Maher ◽  
Sachin Modi ◽  
...  

Abstract Purpose To compare the relative IPSS (International Prostate Symptom Score) improvement in storage and voiding symptoms between prostatic artery embolization (PAE) and transurethral resection of the prostate (TURP). Method Retrospective analysis of the UK-ROPE (UK Register of Prostate Embolization) multicentre database was conducted with inclusion of all patients with full IPSS questionnaire score data. The voiding and storage subscore improvement was compared between interventions. Student’s t-test (paired and unpaired) and ANOVA (Analysis of variance) were used to identify significant differences between the groups. Results 146 patients (121 PAE, 25 TURP) were included in the analysis. Storage symptoms were more frequently the most severe symptom (‘storage’ in 75 patients vs ‘voiding’ in 17 patients). Between groups, no significant difference was seen in raw storage subscore improvement (TURP 4.9 vs PAE 4.2; p = 0.34) or voiding subscore improvement (TURP 8.4 vs PAE 6.7; p = 0.1). ANOVA demonstrated a greater proportionate reduction (relative to total IPSS) towards voiding symptoms in the TURP group (27.3% TURP vs 9.9% PAE, p = 0.001). Conclusion Although both TURP and PAE improve voiding symptoms more than storage, a significantly larger proportion of total symptom reduction is due to voiding in the TURP cohort, with PAE providing a more balanced improvement between voiding and storage.


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