scholarly journals Trunk Disease Fungi Associated With Diospyros kaki in South Africa

Plant Disease ◽  
2016 ◽  
Vol 100 (12) ◽  
pp. 2383-2393 ◽  
Author(s):  
P. Moyo ◽  
L. Mostert ◽  
M. Bester ◽  
F. Halleen

Persimmon trees with dieback symptoms and cankers were observed in three production areas in Western Cape Province in South Africa. Isolations were made from diseased branches, cankers, and pruning wounds as well as fungal fruiting bodies on dead branches and old pruning wounds. Several trunk disease pathogens were identified based on morphological characteristics and by molecular methods, including Diaporthe eres, D. infecunda, Eutypella citricola, E. microtheca, Phaeoacremonium parasiticum, P. scolyti, P. australiense, P. minimum, Fomitiporia capensis, Fomitiporia sp., Fomitiporella sp., and Inocutis sp., which were isolated from persimmon for the first time in the world. Other first reports from persimmon in South Africa include D. foeniculina, D. ambigua, D. mutila, Diaporthe sp., Neofusicoccum australe, N. parvum, Diplodia seriata, and Eutypa lata. Pathogenicity tests conducted with all species, except the basidiomycetes, confirmed their status as possible persimmon pathogens. This is the first study to determine and identify fungi associated with diseased persimmon in South Africa. The knowledge gained in this study forms the basis for further research to determine the impact of these fungi on persimmon productivity.

Plant Disease ◽  
2021 ◽  
Author(s):  
Meagan Van Dyk ◽  
Chris Spies ◽  
Lizel Mostert ◽  
Marieta Van Der Rijst ◽  
Ihan Lambert Du Plessis ◽  
...  

A recent olive trunk disease survey performed in the Western Cape Province, South Africa, identified several fungi associated with olive trunk disease symptoms, including species of Basidiomycota, Botryosphaeriaceae, Coniochaetaceae, Calosphaeriaceae, Diaporthaceae, Diatrypaceae, Phaeomoniellaceae, Phaeosphaeriaceae, Symbiotaphrinaceae, Togniniaceae and Valsaceae. Many of the species recovered had not yet been reported from olive trees and therefore the aim of this study was to determine their pathogenicity towards this host. Pathogenicity tests were first conducted on detached shoots to select virulent isolates which were then used in field trials. During field trials, 2-year-old olive branches of 15-year-old trees were inoculated by inserting colonised agar plugs into artificially wounded tissue. Measurements were made of the internal lesions after 8 months. In total, 58 isolates were selected for the field trials. Species that formed lesions significantly larger than the control could be considered as olive trunk pathogens. These include Biscogniauxia rosacearum, Celerioriella umnquma, Coniochaeta velutina, Coniothyrium ferrarisianum, isolates of the Cytospora pruinosa complex, Didymocyrtis banksiae, Diaporthe foeniculina, Eutypa lata, Fomitiporella viticola, Neofusicoccum stellenboschiana, Nm. vitifusiforme, Neophaeomoniella niveniae, Phaeoacremonium africanum, Pm. minimum, Pm. oleae, Pm. parasiticum, Pm. prunicola, Pm. scolyti, Pm. spadicum, Pleurostoma richardsiae, Pseudophaeomoniella globosa, Punctularia atropurpurascens, Vredendaliella oleae, an undescribed Cytospora sp., Geosmithia sp., two undescribed Neofusicoccum spp. and four Xenocylindrosporium spp. Pseudophaeomoniella globosa can be regarded as one of the main olive trunk pathogens in South Africa, due to its high incidence from olive trunk disease symptoms in established orchards and due to its high virulence in pathogenicity trials.


Plant Disease ◽  
2019 ◽  
Vol 103 (4) ◽  
pp. 711-720 ◽  
Author(s):  
Saleh Panahandeh ◽  
Hamid Mohammadi ◽  
David Gramaje

Syzygium cumini trees with dieback symptoms and cankers were observed in two provinces in Iran. Isolations were made from diseased branches and cankers and from asymptomatic S. cumini wood samples. Several trunk disease pathogens were identified based on morphological characteristics and by molecular methods, including Cadophora luteo-olivacea, Diplodia sapinea, D. seriata, Neoscytalidium hyalinum, Phaeoacremonium fraxinopennsylvanicum, P. krajdenii, P. parasiticum, P. viticola, and Pleurostoma richardsiae, which were isolated from S. cumini for the first time in the world. Pathogenicity tests conducted with all species confirmed their status as possible S. cumini pathogens. N. hyalinum was the most aggressive species and caused the longest lesions on inoculated shoots. The endophytic character of some fungal species isolated from asymptomatic wood of S. cumini is further discussed. Our results indicated that S. cumini is a new woody host to many known fungal trunk pathogens.


2020 ◽  
Author(s):  
Neven Chetty ◽  
Bamise Adeleye ◽  
Abiola Olawale Ilori

BACKGROUND The impact of climate temperature on the counts (number of positive COVID-19 cases reported), recovery, and death rates of COVID-19 cases in South Africa's nine provinces was investigated. The data for confirmed cases of COVID-19 were collected for March 25 and June 30, 2020 (14 weeks) from South Africa's Government COVID-19 online resource, while the daily provincial climate temperatures were collected from the website of the South African Weather Service. Our result indicates that a higher or lower climate temperature does not prevent or delay the spread and death rates but shows significant positive impacts on the recovery rates of COVID-19 patients. Thus, it indicates that the climate temperature is unlikely to impose a strict limit on the spread of COVID-19. There is no correlation between the cases and death rates, an indicator that no particular temperature range is closely associated with a faster or slower death rate of COVID-19 patients. As evidence from our study, a warm climate temperature can only increase the recovery rate of COVID-19 patients, ultimately impacting the death and active case rates and freeing up resources quicker to enable health facilities to deal with those patients' climbing rates who need treatment. OBJECTIVE This study aims to investigate the impact of climate temperature variation on the counts, recovery, and death rates of COVID-19 cases in all South Africa's provinces. The findings were compared with those of countries with comparable climate temperature values. METHODS The data for confirmed cases of COVID-19 were collected for March 25 and June 30 (14 weeks) for South African provinces, including daily counts, death, and recovery rates. The dates were grouped into two, wherein weeks 1-5 represent the periods of total lockdown to contain the spread of COVID-19 in South Africa. Weeks 6-14 are periods where the lockdown was eased to various levels 4 and 3. The daily information of COVID-19 count, death, and recovery was obtained from South Africa's Government COVID-19 online resource (https://sacoronavirus.co.za). Daily provincial climate temperatures were collected from the website of the South African Weather Service (https://www.weathersa.co.za). The provinces of South Africa are Eastern Cape, Western Cape, Northern Cape, Limpopo, Northwest, Mpumalanga, Free State, KwaZulu-Natal, Western Cape, and Gauteng. Weekly consideration was given to the daily climate temperature (average minimum and maximum). The recorded values were considered, respectively, to be in the ratio of death-to-count (D/C) and recovery-to-count (R/C). Descriptive statistics were performed for all the data collected for this study. The analyses were performed using the Person’s bivariate correlation to analyze the association between climate temperature, death-to-count, and recovery-to-count ratios of COVID-19. RESULTS The results showed that higher climate temperatures aren't essential to avoid the COVID-19 from being spread. The present results conform to the reports that suggested that COVID-19 is unlike the seasonal flu, which does dissipate as the climate temperature rises [17]. Accordingly, the ratio of counts and death-to-count cannot be concluded to be influenced by variations in the climate temperatures within the study areas. CONCLUSIONS The study investigates the impact of climate temperature on the counts, recovery, and death rates of COVID-19 cases in all South Africa's provinces. The findings were compared with those of countries with comparable climate temperatures as South Africa. Our result indicates that a higher or lower climate temperature does not prevent or delay the spread and death rates but shows significant positive impacts on the recovery rates of COVID-19 patients. Warm climate temperatures seem not to restrict the spread of the COVID-19 as the count rate was substantial at every climate temperatures. Thus, it indicates that the climate temperature is unlikely to impose a strict limit on the spread of COVID-19. There is no correlation between the cases and death rates, an indicator that there is no particular temperature range of the climatic conditions closely associated with a faster or slower death rate of COVID-19 patients. However, other shortcomings in this study's process should not be ignored. Some other factors may have contributed to recovery rates, such as the South African government's timely intervention to announce a national lockout at the early stage of the outbreak, the availability of intensive medical care, and social distancing effects. Nevertheless, this study shows that a warm climate temperature can only help COVID-19 patients recover more quickly, thereby having huge impacts on the death and active case rates.


Koedoe ◽  
2001 ◽  
Vol 44 (2) ◽  
Author(s):  
J. Heyns

A population of Xiphinema bolandium from the Baviaanskloof Wilderness Area in the Eastern Cape Province was studied, and the four juvenile stages described and figured for the first time. New distribution records are listed from several localities in the Western Cape Province, mostly from vineyards and peach orchards, as well as from fynbos.


Plant Disease ◽  
2010 ◽  
Vol 94 (2) ◽  
pp. 244-249 ◽  
Author(s):  
G. Pietersen ◽  
E. Arrebola ◽  
J. H. J. Breytenbach ◽  
L. Korsten ◽  
H. F. le Roux ◽  
...  

Greening disease of citrus is a serious disease known in South Africa since the late 1920s. In South Africa, it is associated with infection by ‘Candidatus Liberibacter africanus’, a heat sensitive, phloem-limited, noncultured alpha-proteobacterium. Huanglongbing (HLB), a similar, but more devastating disease that was described initially from China but which now occurs in several citrus producing countries, is associated with a different Liberibacter species, ‘Ca. L. asiaticus’. A ‘Ca. L. africanus’ subspecies, ‘Ca. L. africanus subsp. capensis’, has been found only in South Africa infecting an indigenous Rutaceous species, Calodendrum capense (Cape Chestnut), in the Western Cape in 1995. The discovery of a new Liberibacter species in Brazil, ‘Ca. L. americanus’, and the spread of ‘Ca. L. asiaticus’ to a number of additional countries over the last few years prompted us to assess whether only ‘Ca. L. africanus’ is present in commercial citrus orchards in South Africa. Samples displaying greening or similar symptoms were collected from 249 citrus trees from 57 orchards distributed throughout the greening affected citrus production areas of South Africa. Multiplex polymerase chain reaction (PCR) was performed on DNA extracts to detect the known citrus Liberibacters. Amplicons were obtained from 197 samples. None of the samples yielded a 1,027-bp amplicon indicative of ‘Ca. L. americanus’ infection. The amplicons of 84 samples were sequenced, and all were identical to the cognate ‘Ca. L. africanus’ Nelspruit sequence in GenBank. No instance of ‘Ca. L. asiaticus’ or ‘Ca. L. africanus subsp. capensis’ sequence was found. Geographically representative samples that tested negative for Liberibacter also tested negative for phytoplasmas based on real-time PCR results. Based on the results of this survey, it is concluded that to date only ‘Ca. L. africanus’ is associated with citrus greening in commercial citrus in South Africa.


Author(s):  
C.J. Botha ◽  
R.A. Schultz ◽  
J.J. Van der Lugt ◽  
C. Archer

Krimpsiekte (the syndrome associated with chronic cardiac glycoside poisoning) was purportedly induced by Ornithogalum toxicarium in the Karas mountains area of Keetmanshoop, Namibia. This chinkerinchee species was previously linked to a condition known as 'kwylbek' krimpsiekte in small stock in the Beaufort West district of the Western Cape Province, South Africa. In a dosing trial, respiratory distress, tachycardia and sternal recumbency were observed in 2 sheep drenched with fresh plant material. A fluorescence polarisation immunoassay (FPIA) detected the presence of a substance that cross-reacted with digoxin antibodies in some of the plant material collected at Keetmanshoop and Beaufort West. This is the first time that apparent cardiac glycoside poisoning was induced by a southern African chinkerinchee species. The presence of the cardiac glycoside-like substance in O. toxicarium requires further chemical verification.


Revista CERES ◽  
2017 ◽  
Vol 64 (3) ◽  
pp. 250-257
Author(s):  
Joaquín Guillermo Ramírez Gil ◽  
Pablo Julián Tamayo ◽  
Juan Gonzalo Morales

ABSTRACT Purple passion fruit (Passiflora edulis f. edulis Sims, known in Colombia as “gulupa”) is an increasingly important crop in Colombia, as seen by an increase in the area under cultivation. This recent prominence coincides with a low number of existing technologies related to the cultivation of the fruit, resulting in a lack of knowledge about its associated pathogens and the absence of rapid and precise diagnostic tests. The objective of this study was to determine the pathogenicity of distinct microorganisms isolated from purple passion fruit samples, some of which had not been previously reported in Colombia. The sampling was performed in seven plots located in two regions of the Colombian Antioquia. With the use of field symptomatology, the isolation of microorganisms, morphological characteristics, molecular analysis, and pathogenicity tests, the pathogen species Phytophthora nicotianae var. parasitica, Colletotrichum gloeosporioides sensu lato, and Phytophthora drechsleri were identified for the first time in Colombia. These pathogens cause lesions in fruits, with an incidence of 10.9, 7.6, and 2.8%, respectively. This is also the first report on a global level of Phytophthora drechsleri causing a disease in this plant species.


Author(s):  
Rekai L. Chinhoyi ◽  
Moleen Zunza ◽  
Klaus B. Von Pressentin

Background: A revised family physician (FP) training programme was introduced in South Africa in 2007. A baseline assessment (2011) of the impact of FP supply on district health system performance was performed within the Western Cape Province, South Africa. The impact of an increased FP supply within this province required re-evaluation.Aim: To assess the impact of FP supply on indicators of district health system performance, clinical processes and clinical outcomes in the Western Cape Province. The objectives were to determine the impact of FPs, nurses, medical officers (MOs) and other specialists.Setting: The study sample included all five rural districts and eight urban subdistricts of the Western Cape Province.Methods: A secondary analysis was performed on routinely collected data from the Western Cape Department of Health from 01 March 2011 until 30 April 2014.Results: The FP supply did not significantly impact the indicators analysed. The supply of nurses and MOs had an impact on some of the indicators analysed.Conclusion: This study did not replicate the positive associations between an increase in FP supply and improved health indicators, as described previously for high-income country settings. The impact of FP supply on clinical processes, health system performance and outcome indicators in the Western Cape Province was not statistically significant. Future re-evaluation is recommended to allow for more time and an increase in FP supply.


Phytotaxa ◽  
2020 ◽  
Vol 459 (2) ◽  
pp. 139-154
Author(s):  
CORNELIA KLAK ◽  
PAVEL HANÁČEK ◽  
ODETTE CURTIS-SCOTT ◽  
ANSO LE ROUX ◽  
PETER V. BRUYNS

A phylogeny of all nine subgenera of Drosanthemum, based on chloroplast sequence-data, is presented. The results confirm some previously published facts, e.g. that D. zygophylloides is sister to Drosanthemum. We propose to treat this species as a new monotypic genus, Lemonanthemum, which differs from Drosanthemum in features of the leaves and fruit-stalks. In Drosanthemum s.s., the small subg. Quadrata, characterized by 4-locular fruits, is highly supported as sister to the remainder of Drosanthemum (where fruits are 5-locular). Further, our data support the transfer of Delosperma pubipetalum to Drosanthemum (where a nomenclatural change is also made). The pubescent petals, 5-locular fruits with narrow covering membranes and downward-pointing hair-like papillae on the branches suggest that D. pubipetalum is close to D. papillatum and belongs to subg. Quastea. Another species, D. badspoortense, which had been placed in D. subg. Quastea on account of its narrow covering membranes, is shown to belong to Delosperma and also lacks the unique structure of the fruit-stalk of Drosanthemum. In addition, a new species, D. overbergense, is described from disjunct patches of remnant renosterveld within the Overberg and near Albertinia, in the Western Cape of South Africa. Morphological characteristics suggest that this species belongs to subg. Xamera, but this was not corroborated by our molecular data. Finally, a new name—Drosanthemum calcareum—is proposed for the illegitimate D. intermedium and a lectotype (at BOL) is designated for D. pubipetalum. The lectotypification of D. badspoortense is also proposed.


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