scholarly journals Phytophthora root rot: its impact in botanic gardens and on threatened species conservation

2020 ◽  
pp. 89-104
Author(s):  
Brett Summerell ◽  
Edward Liew
Keyword(s):  
Threatened Species ◽  
Root Rot ◽  
Species Conservation ◽  
Phytophthora Species ◽  
Ex Situ ◽  
Botanic Gardens ◽  
Natural Ecosystems ◽  
Phytophthora Root Rot ◽  
A Site ◽  
The Impact

Phytophthora root rot is one of the most devastating diseases of perennial plants worldwide, affecting plants in food production, amenity plantings and in natural ecosystems. The impact of these diseases in botanic gardens can be substantial and can affect how a site may be used for months and years ahead. Management is critically dependent on avoidance of the introduction of the pathogen and effective hygiene protocols are key to achieving this. Additionally, botanic gardens have a key role to play in protecting plants and enhancing conservation outcomes through surveillance, education and ex situ conservation programmes, as well as through the recognition that they can be critical as sentinel sites to detect new incursions of pests anddiseases. The impact of several Phytophthora species on the in situ and ex situ management of the critically endangered Wollemia nobilis (Wollemi pine), which is highly susceptible to phytophthora root rot, is used to highlight the need to ensure management of these pathogens is a critical component of threatened species recovery and management.

scholarly journals Conservation of threatened plant species in botanic garden reserves in Brazil

Oryx ◽  
2016 ◽  
Vol 52 (1) ◽  
pp. 108-115 ◽  
Author(s):  
Maria Lúcia M. N. da Costa ◽  
Peter Wyse Jackson ◽  
Ricardo Avancini Fernandes ◽  
Ariane Luna Peixoto
Keyword(s):  
Plant Species ◽  
Threatened Species ◽  
In Situ Conservation ◽  
Integrated Approach ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Botanic Gardens ◽  
Threatened Plant Species ◽  
Integrated Conservation ◽  
Scientific Value

AbstractOver the last few decades botanic gardens worldwide have been encouraged to adopt complementary measures for the conservation of plant species from their own regions, combining in situ conservation efforts with ex situ methods, both in cultivation and in storage. This integrated approach is particularly important for botanic gardens in the tropics, which face the challenge of conserving a highly diverse and often threatened flora. We gathered information on the occurrence of threatened species in the natural vegetation reserves of 21 Brazilian botanic gardens. The data were collected from herbarium records in the database of the National Centre for Flora Conservation, and from the available plant inventories of these reserves. The results indicate that 148 species from the List of Threatened Species of Brazilian Flora are recorded as having been collected in the reserves. Of these, 51 species were maintained in the living collections of 18 botanic gardens and 83 species were recorded in federally protected areas. The occurrence of threatened species in the reserves of botanic gardens highlights the scientific value of these areas, as well as their biological, social and cultural importance for conservation. The results may be used to inform the planning of integrated conservation strategies for threatened species.

scholarly journals Variation in Disease Severity Caused by Phytophthora cinnamomi, P. plurivora, and Pythium cryptoirregulare on Two Rhododendron Cultivars

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2560-2570 ◽  
Author(s):  
Jerry E. Weiland ◽  
Carolyn F. Scagel ◽  
Niklaus J. Grünwald ◽  
E. Anne Davis ◽  
Bryan R. Beck ◽  
...  
Keyword(s):  
Disease Control ◽  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Severe Disease ◽  
Phytophthora Species ◽  
Relative Resistance ◽  
Inoculum Level ◽  
Phytophthora Root Rot ◽  
Mild Disease ◽  
Comparative Information

Rhododendrons are an important crop in the ornamental nursery industry, but are prone to Phytophthora root rot. Phytophthora root rot is a continuing issue on rhododendrons despite decades of research. Several Phytophthora species are known to cause root rot, but most research has focused on P. cinnamomi, and comparative information on pathogenicity is limited for other commonly encountered oomycetes, including Phytophthora plurivora and Pythium cryptoirregulare. In this study, three isolates each of P. cinnamomi, P. plurivora, and Py. cryptoirregulare were used to inoculate rhododendron cultivars Cunningham’s White and Yaku Princess at two different inoculum levels. All three species caused disease, especially at the higher inoculum level. P. cinnamomi and P. plurivora were the most aggressive pathogens, causing severe root rot, whereas Py. cryptoirregulare was a weak pathogen that only caused mild disease. Within each pathogen species, isolate had no influence on disease. Both P. cinnamomi and P. plurivora caused more severe disease on Cunningham’s White than on Yaku Princess, suggesting that the relative resistance and susceptibility among rhododendron cultivars might be similar for both pathogens. Reisolation of P. cinnamomi and P. plurivora was also greater from plants exhibiting aboveground symptoms of wilting and plant death and belowground symptoms of root rot than from those without symptoms. Results show that both P. cinnamomi and P. plurivora, but not Py. cryptoirregulare, are important pathogens causing severe root rot in rhododendron. This study establishes the risks for disease resulting from low and high levels of inoculum for each pathogen. Further research is needed to evaluate longer term risks associated with low inoculum levels on rhododendron health and to explore whether differences among pathogen species affect disease control.

scholarly journals The role of the Francisco Javier Clavijero Botanic Garden (Xalapa, Veracruz, Mexico) in the conservation of the Mexican flora

2021 ◽  
Author(s):  
Milton Díaz-Toribio ◽  
Victor Luna ◽  
Andrew Vovides
Keyword(s):  
Plant Species ◽  
Threatened Species ◽  
Cloud Forest ◽  
Vascular Plant ◽  
Plant Conservation ◽  
Ex Situ ◽  
Botanic Gardens ◽  
Botanic Garden ◽  
Threatened Plant ◽  
Threatened Plant Species

Background and Aims: There are approximately 3000 botanic gardens in the world. These institutions cultivate approximately six million plant species, representing around 100,000 taxa in cultivation. Botanic gardens make an important contribution to ex situ conservation with a high number of threatened plant species represented in their collections. To show how the Francisco Javier Clavijero Botanic Garden (JBC) contributes to the conservation of Mexican flora, we asked the following questions: 1) How is vascular plant diversity currently conserved in the JBC?, 2) How well is this garden performing with respect to the Global Strategy for Plant Conservation (GSPC) and the Mexican Strategy for Plant Conservation (MSPC)?, and 3) How has the garden’s scientific collection contributed to the creation of new knowledge (description of new plant species)?Methods: We used data from the JBC scientific living collection stored in BG-BASE. We gathered information on species names, endemism, and endangered status, according to national and international policies, and field data associated with each species. Key results: We found that 12% of the species in the JBC collection is under some risk category by international and Mexican laws. Plant families with the highest numbers of threatened species were Zamiaceae, Orchidaceae, Arecaceae, and Asparagaceae. We also found that Ostrya mexicana, Tapirira mexicana, Oreopanax capitatus, O. echinops, and O. xalapensis are highly threatened species representative of cloud forest currently in the collection. Conclusions: The conservation and scientific utility of the JBC collection is reflected in the exceptional accession data and the description of 24 new plant species. Having a significant number of threatened plant species in its ex situ collection, the JBC contributes to the implementation of the GSPC, particularly Target 8, as well as the implementation of the MSPC.

Virulence of five Phytophthora species causing rhododendron root rot in Oregon.

Plant Disease ◽  
2021 ◽  
Author(s):  
Gabe O. Sacher ◽  
Carolyn F. Scagel ◽  
E. Anne Davis ◽  
Bryan R. Beck ◽  
Jerry E. Weiland
Keyword(s):  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Block Design ◽  
Abundant Species ◽  
Phytophthora Species ◽  
Phytophthora Root Rot ◽  
Moderate Disease ◽  
Randomized Complete Block Design ◽  
Infested Field ◽  
Production Areas

Phytophthora root rot is a destructive disease of rhododendron, causing substantial losses of this nursery crop in infested field and container production areas. Historically, Phytophthora cinnamomi was considered the main causal agent of the disease. However, a recent survey of soilborne Phytophthora species from symptomatic rhododendrons in Oregon revealed that P. plurivora is more common than P. cinnamomi and that several other Phytophthora species may also be involved. We investigated the ability of the five most abundant species from the survey to cause root rot: P. plurivora, P. cinnamomi, P. pini, P. pseudocryptogea, and P. cambivora. Three to four isolates were selected for each species from across six Oregon nurseries. Media of containerized Rhododendron catawbiense ‘Boursault’ was infested with single isolates in a randomized complete block design in a greenhouse. Phytophthora cinnamomi, P. pini, and P. plurivora rapidly caused ≥ 90% incidence of severe root rot while P. pseudocryptogea caused more moderate disease with 46% incidence of severe root rot. Phytophthora cambivora failed to produce enough inoculum and was used at a lower inoculum density than the other four species, but occasionally caused severe root rot (5% incidence). No differences in virulence were observed among isolates of same species, except for one isolate of P. plurivora that caused less disease than other P. plurivora isolates. This study demonstrates that all five Phytophthora species, which were representative of 94% of the survey isolates, are capable of causing severe root rot and plant death, but that not all species are equally virulent.

Susceptibility of Garden Plants to Phytophthora Root Rot

Plant Disease ◽  
2020 ◽  
Author(s):  
Liz Beal ◽  
Ian Waghorn ◽  
Joe Perry ◽  
Gerard R G Clover ◽  
Matthew Cromey
Keyword(s):  
Host Range ◽  
Root Rot ◽  
Woody Plants ◽  
Integrated Management ◽  
Common Species ◽  
Phytophthora Species ◽  
High Index ◽  
Phytophthora Root Rot ◽  
Wide Host Range ◽  
Serious Disease

Phytophthora root rot (PRR) is a serious disease of horticultural, forest and ornamental plant species caused by species of the oomycete genus Phytophthora. Their wide host range makes choice of resistant plants in management of the disease difficult. We used the Royal Horticultural Society diagnostic dataset of PRR records from U.K. gardens to compare the susceptibility of different host genera to the disease. The dataset was compared with existing reports of plants recorded as notably resistant or notably susceptible to PRR. An index-based approach was used to separate 177 genera of woody plants into three categories: 85 were low-index (<0.10: rarely affected), 34 were medium-index (0.10 – 0.20: sometimes affected) and 58 were high-index (>0.20: frequently affected). Similarly, genera of non-woody plants were separated into: 45 low-index (<0.22), 16 medium-index (0.22 – 0.44) and 18 high-index (>0.44). Taxus was the genus with the highest index, while most genera in the Malvales and Ericales were in the high index group. Most genera in the Myrtales, Fabales and Monocotyledons were low index. Whilst 30 Phytophthora species were recorded in our study, the wide host range spp., P. plurivora, P. cryptogea and P. cinnamomi represented 63% of identifications. Phytophthora plurivora was the most common species on woody plants and P. cryptogea on non-woody plants. These results provide confidence in the use of host resistance as part of the integrated management of PRR.

scholarly journals The Impact of Phytophthora Root Rot on Water Extraction from Soil by Roots of Field-grown Processing Tomatoes

1991 ◽  
Vol 116 (4) ◽  
pp. 603-608 ◽  
Author(s):  
J.B. Ristaino ◽  
J.M. Duniway
Keyword(s):  
Root Rot ◽  
Disease Onset ◽  
Water Extraction ◽  
Total Water ◽  
Tomato Root ◽  
Phytophthora Root Rot ◽  
Tomato Roots ◽  
The Impact ◽  
Field Plots ◽  
Processing Tomatoes

Processing tomatoes (Lycopersicon esculentum Mill.) grown in field plots with soil infested with or free of Phytophthora parasitic Dastur. were furrow-irrigated for 4 to 8 hours every 14 days (normal irrigation), for 4 to 8 hours every 28 days (less frequent irrigation), or for 4 to 8 and 24 hours on alternate irrigations every 14 days (prolonged irrigation). Disease developed more rapidly and symptom severity was greater in inoculated plants that received prolonged irrigation, whereas disease onset was delayed in inoculated plants that were irrigated less frequently. Water extraction by tomato roots from well-irrigated and noninfested soil was usually greatest at shallow depths and decreased with depth. When disease was increasing and soil moisture was high, diseased plants extracted less total water from all depths and significantly less water at shallow depths. Plants in the drier soil profiles extracted the greatest amounts of water at depths below 90 cm, and diseased plants irrigated less frequently showed reductions in water extraction at shallow depths later in the season. Tomato root systems appeared to compensate for moderate levels of root disease at shallow depths by extracting more water from deeper in the profile.

scholarly journals Ex situ species conservation: Predicting plant survival in botanic gardens based on climatic provenance

2022 ◽  
Vol 265 ◽  
pp. 109410
Author(s):  
Georgia Thomas ◽  
Rebecca Sucher ◽  
Andrew Wyatt ◽  
Iván Jiménez
Keyword(s):  
Species Conservation ◽  
Ex Situ ◽  
Botanic Gardens ◽  
Plant Survival

scholarly journals An analysis of Species Conservation Action Plans in Guinea

2020 ◽  
Author(s):  
Charlotte Couch ◽  
Denise Molmou ◽  
Sékou Magassouba ◽  
Saïdou Doumbouya ◽  
Mamadou Diawara ◽  
...  
Keyword(s):  
Plant Species ◽  
Threatened Species ◽  
Species Conservation ◽  
Iucn Red List ◽  
Red List ◽  
Ex Situ ◽  
Action Plans ◽  
Conservation Action ◽  
Threatened Plant ◽  
Threatened Plant Species

AbstractTo achieve conservation success, we need to support the recovery of threatened species. Yet, <5% of plant species listed as threatened on the IUCN Red List have Species Conservation Action Plans (CAPs). If we are to move from a Red List to a Green List for threatened plant species, CAPs need to be devised and implemented. Guinea is one of the most botanically diverse countries in West Africa. Recent research found that nearly 4000 vascular plants occur in Guinea, a 30% increase from previous estimates. 273 of these plant species are now assessed as threatened with global extinction. There is increasing pressure on the environment from the extractive industry and a growing population. In parallel with implementation of an Important Plant Area programme in Guinea, CAPs were developed for 20 threatened plant species. These plans elaborate conservation efforts needed first to safeguard threatened species both in situ and ex situ and then to support their recovery. We document the approach used to assemble the Species Conservation Action Plans, and we discuss the importance of having up to date field information, IUCN Red List assessments, and use of a collaborative approach. The need for these plans is increasingly important with recent calculations suggesting a third of African plants are threatened with extinction. This paper outlines initial detailed plant conservation planning in Guinea and offers a template for conservation practitioners in other tropical African countries to follow.

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