scholarly journals Honeybush (Cyclopia spp.) phenology and associated arthropod diversity in the Overberg region, South Africa

Bothalia ◽  
2019 ◽  
Vol 49 (1) ◽  
Author(s):  
Eleonore L. Slabbert ◽  
Rhoda R. Malgas ◽  
Ruan Veldtman ◽  
Pia Addison
Keyword(s):  
South Africa ◽  
Management Practices ◽  
Cape Floristic Region ◽  
Arthropod Community ◽  
Western Cape ◽  
Baseline Knowledge ◽  
Medicinal Properties ◽  
High Level ◽  
Production Areas ◽  
Suction Sampling

Background: Cyclopia is endemic to regions of the Cape Floristic Region across the Eastern and Western Cape provinces of South Africa and is commonly known as honeybush. Honeybush has historically been used as an herbal tea, and has proven medicinal properties. Honeybush biomass and extracts are used in the functional foods and cosmetics sectors, both locally and overseas. The growing demand for honeybush calls for increased agricultural production and a shift away from the predominantly wild harvested supply.Objectives: The current study aimed to address the lack of baseline knowledge on honeybush phenology and its associated arthropod community to advance sustainable production of commercially valued plants in the genus.Method: The study was conducted on wild and cultivated Cyclopia species (Cyclopia maculata and Cyclopia genistoides) at respective sites in the Overberg region. Sampling took place from April 2014 to April 2015 using qualitative methods for recording seasonal honeybush phenology and suction sampling for aboveground arthropods. Focal insect taxa (Coleoptera, Hemiptera, Thysanoptera, Lepidoptera and Hymenoptera) were sorted and identified to family level and classified into functional feeding guilds.Results: Qualitative phenology observations of wild C. maculata and cultivated C. genistoides indicated a high level of congruency in seasonality of phenophase stages. Associated arthropod assemblages contained a diversity of families per functional feeding group, namely phytophagous, zoophagous and omnivorous taxa, with high seasonal variability.Conclusion: Findings highlight the complexity of ecological elements to be taken into consideration for ecologically sound honeybush cultivation. Outcomes can be applied to land management practices and governance policies promoting sustainable agroecosystems in honeybush production areas.

scholarly journals A Survey for ‘Candidatus Liberibacter’ Species in South Africa Confirms the Presence of Only ‘Ca. L. africanus’ in Commercial Citrus

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 ◽  
...  
Keyword(s):  
South Africa ◽  
Western Cape ◽  
Chain Reaction ◽  
Citrus Production ◽  
Candidatus Liberibacter ◽  
Citrus Orchards ◽  
Polymerase Chain ◽  
Serious Disease ◽  
Production Areas ◽  
Representative Samples

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.

Vegetation and vegetation-environment relationships at Grootbos Nature Reserve, Western Cape, South Africa

Bothalia ◽  
2008 ◽  
Vol 38 (1) ◽  
pp. 89-102 ◽  
Author(s):  
M. Mergili ◽  
S. Privett
Keyword(s):  
South Africa ◽  
Nature Reserve ◽  
Soil Depth ◽  
Vegetation Type ◽  
Cape Floristic Region ◽  
Western Cape ◽  
Floristic Diversity ◽  
Rock Cover ◽  
Scrub Forest ◽  
Fire Incidence

The private Grootbos Nature Reserve is located at the Western edge of the Agulhas Plain in the Cape Floristic Region of South Africa, an area characterized by high habitat and floristic diversity. The Reserve is covered in near-natural fynbos shrublands with a few patches of forest and wetland. The main objective of this study was to classify the vegetation into discrete units and relate them to the prevailing environmental conditions. The vegetation was analysed by numerical means (TWINSPAN, DC A, CCA) and mapped on GIS. At the vegetation type level. Forest Thicket and Fynbos formed distinctive clusters, whereas the wetland releves were intermixed, but without relationships to one of these units. Fire incidence served as the major determinant of the forest-fynbos boundary. The Forest Thicket grouping was separated into Thicket (as transitional to fynbos), Afromontane Forest and Milkwood Scrub Forest. Two broad complexes were distinguished within the Fynbos grouping, the Alkaline Sand Fynbos Complex corresponding to Coastal Fynbos. and the Acid Sand Fynbos Complex corresponding to Mountain Fynbos. They discriminated along gradients of pH. soil depth and rock cover. The complexes were further subdivided into formations by using one or a few subjectively chosen dominant species as indicators. The transitions between these formations were rather continuous than discrete. The vegetation type and complex levels correspond well to existing fynbos-wide classifications. Comparing the formations to the results of other vegetation studies is problematic even on the scale of the Agulhas Plain, due to the high regional plant diversity in the Fynbos Biome.

The Quality of Biodiversity Inputs to EIA in Areas with High Biodiversity Value — Experience from the Cape Floristic Region, South Africa

2015 ◽  
Vol 17 (03) ◽  
pp. 1550025 ◽  
Author(s):  
Trevor Winston Hallatt ◽  
Francois Pieter Retief ◽  
Luke Alan Sandham
Keyword(s):  
South Africa ◽  
Best Practice ◽  
Cape Floristic Region ◽  
Public Consultation ◽  
Western Cape ◽  
Impact Prediction ◽  
International Trends ◽  
Report Quality ◽  
Insufficient Time

The quality of biodiversity inputs to Environmental Impact Assessment (EIA) in areas with high biodiversity value was investigated by reviewing the quality of a sample of Biodiversity Impact Assessments (BIAs) in the Cape Floristic Region (CFR), South Africa. The results suggest that while the overall performance was satisfactory, several inadequacies were evident, confirming international trends. Inadequacies relate to consideration of alternatives, public consultation, monitoring programmes, and gathering of biodiversity baseline data during inappropriate seasons and over insufficient time periods. Positive outcomes include the incorporation of ecosystems processes in baseline studies and assessment as well as the wide adoption of a precautionary approach to impact prediction. It is recommended that best practice and biodiversity guidance as developed and implemented in the Western Cape Province, be adopted as widely as possible in other provinces, and that the BIA practitioner community be alerted to revealed weakness of BIA report quality.

scholarly journals A New Pathotype of Puccinia striiformis f. sp. tritici on Wheat in South Africa

Plant Disease ◽  
1999 ◽  
Vol 83 (6) ◽  
pp. 591-591 ◽  
Author(s):  
W. H. P. Boshoff ◽  
Z. A. Pretorius
Keyword(s):  
South Africa ◽  
Stripe Rust ◽  
Puccinia Striiformis ◽  
Single Step ◽  
Western Cape ◽  
Monogenic Resistance ◽  
Major Resistance Gene ◽  
New Variant ◽  
Production Areas ◽  
Wheat Lines

Following the detection of Puccinia striiformis f. sp. tritici for the first time on wheat (Triticum aestivum) in the Western Cape in August 1996, stripe rust has spread to all the important wheat production areas in South Africa. Only the introduced pathotype (pt. 6E16) was detected in surveys of these areas during 1996 and 1997. In 1998, a severe stripe rust epidemic occurred in the eastern Free State on the extensively grown cultivars Hugenoot and Carina, both which are resistant to pt. 6E16. Stripe rust severities of 100% were common on flag and lower leaves, and widespread applications of fungicides were necessary. Avirulence/virulence characteristics of P. striifomis f. sp. tritici isolates collected from Hugenoot and Carina were determined on 17 standard stripe rust differential wheat lines and 11 supplementary testers. The latter testers included the wheat lines TP981 and TP1295 (supplied by R. Johnson, Cambridge, UK), both of which have a major resistance gene in common with the differentials Heines Peko, Reichersberg 42, Strubes Dickkopf, Clement, and Heines VII (1). Isolates obtained from Hugenoot and Carina differed from pt. 6E16 based on virulence to Reichersberg 42 (Yr7,25), Heines Peko (Yr2,6,25), TP981 (Yr25), and TP1295 (Yr25). The new variant, designated as 6E22, was also identified in collections from the province KwaZulu-Natal. Seedling tests with 6E16 and 6E22 have shown that Hugenoot, Carina, and Tugela-DN are the only local cultivars affected by the new pathotype. The occurrence of pt. 6E22, which appears to be a single-step adaptation from 6E16 adding virulence to Yr25, emphasizes the vulnerability of monogenic resistance to this disease. Reference: (1) R. A. McIntosh et al. Wheat Inform. Serv. 85:56, 1997.

scholarly journals New scale insects (Homoptera: Coccinea) from the Cape Floristic Region

2017 ◽  
Author(s):  
Ilya A. Gavrilov-Zimin ◽  
Philipp E. Chetverikov
Keyword(s):  
South Africa ◽  
Scale Insect ◽  
Cape Floristic Region ◽  
Scale Insects ◽  
Insect Species ◽  
Western Cape ◽  
Western Cape Province ◽  
The Family

Three new scale insect species, Coccidohystrix daedalea Gavrilov-Zimin sp. nov., Mirococcopsis ptilura Gavrilov-Zimin sp. nov. (both from the family Pseudococcidae) and Cryptinglisia millari Gavrilov-Zimin sp. nov. (family Coccidae), are described and illustrated from the Western Cape Province of South Africa.

New species and taxonomic changes within Pentaschistis (Danthonioideae, Poaceae) from Western Cape, South Africa

Bothalia ◽  
2006 ◽  
Vol 36 (2) ◽  
pp. 157-162 ◽  
Author(s):  
C. A. Galley ◽  
H. P. Linder
Keyword(s):  
South Africa ◽  
New Species ◽  
Cape Floristic Region ◽  
Western Cape ◽  
Coastal Plains ◽  
Fold Belt ◽  
Western Border ◽  
Taxonomic Changes ◽  
Three New Species ◽  
Cape Fold Belt

Three new species of Pentaschistis (Nees) Stapf are described from the Cape Floristic Region. P. trifida. P clavata and P. horrida. The former has been collected from inland ranges of the Cape Fold Belt, from the Cederberg to the Groot Swartberg. the last two each from single sites in the Koue Bokkeveld:  P. clavata on the wetter western border, and P. horrida on the Baviaansberg. Pentaschistis juncifolia Stapf is re-instated, a species from the coastal plains (Hardeveld) between Bredasdorp and Riversdale, which had been included in P. eriostoma (Nees) Stapf.

Population genetic analyses of Phytophthora cinnamomi reveals three lineages and movement between natural vegetation and avocado orchards in South Africa

2022 ◽  
Author(s):  
Juanita Engelbrecht ◽  
Tuan A. Duong ◽  
Trudy Paap ◽  
Joseph Michael Hulbert ◽  
Juanita Joyce Hanneman ◽  
...  
Keyword(s):  
South Africa ◽  
Genetic Diversity ◽  
Phytophthora Cinnamomi ◽  
Resistance Breeding ◽  
Natural Vegetation ◽  
Economic Losses ◽  
Western Cape ◽  
Natural Ecosystems ◽  
Agricultural Industries ◽  
Production Areas

Phytophthora cinnamomi is the causal agent of root rot, canker and dieback of thousands of plant species around the globe. This oomycete not only causes severe economic losses to forestry and agricultural industries, but also threatens the health of various plants in natural ecosystems. In this study, 380 isolates of P. cinnamomi from four avocado production areas and two regions of natural vegetation in South Africa were investigated using 15 microsatellite markers. These populations were found to have a low level of genetic diversity and consisted of isolates from three lineages. Shared genotypes were detected between isolates from avocado orchards and natural vegetation, indicating the movement of isolates between these areas. The population from the Western Cape natural vegetation had the highest genotypic diversity and unique alleles, indicating this could be the point of introduction of P. cinnamomi to South Africa. Index of association analysis suggested that five out of six populations were under linkage disequilibrium suggesting a clonal mode of reproduction whereas genotypes sampled from a recently established avocado orchard in the Western Cape were derived from a randomly recombined population. This study provided novel insights on the genetic diversity and spread of P. cinnamomi in South Africa. It also reported on the predominance of triploidy in natural occurring populations and provided evidence for recombination of P. cinnamomi for the first time. The presence of two dominant genotypes in all avocado production areas in South Africa highlight the importance of considering them in disease management and resistance breeding programmes.

Occurrence of Canker and Wood Rot Pathogens on Stone Fruit Propagation Material and Nursery Trees in the Western Cape of South Africa

Plant Disease ◽  
2021 ◽  
Author(s):  
Rhona van der Merwe ◽  
Francois Halleen ◽  
Meagan Van Dyk ◽  
Vernon Guy Jacobs ◽  
Lizel Mostert
Keyword(s):  
South Africa ◽  
Management Practices ◽  
Phylogenetic Analyses ◽  
Fruit Trees ◽  
Fungal Species ◽  
Stone Fruit ◽  
Western Cape ◽  
Latent Infections ◽  
Nursery Trees ◽  
Propagation Material

Dieback and canker of young stone fruit trees can cause suboptimal growth and even death under severe conditions. One source of inoculum of canker pathogens could be through nursery trees harboring latent infections that would not be visible to inspections done according to the deciduous fruit scheme. The objectives of this study were to identify the canker and wood rot fungal pathogens present in nursery stone fruit trees as well as propagation material and to evaluate their pathogenicity. Isolations were made from scion and rootstock propagation material and from certified nursery stone fruit trees. The plant material sampled did not have any external symptoms. The certified nursery trees when cross-sectioned displayed brown discoloration from the pruning wound, bud union and often from the crown. Fungal species isolated were identified by sequencing of the relevant barcoding genes and phylogenetic analyses thereof. Canker and wood rot associated fungi were identified. Buds used for budding had low levels of infection, with 1.2% of dormant buds infected and 0.4% of green buds infected. The dormant rootstock shoots had canker pathogen incidence of 6.2% before it was planted in the nursery fields and increased as the ungrafted, rooted rootstock plants had 11.1% infection with canker and wood rot pathogens. Out of 1080 nursery trees, the canker and wood rot associated fungi infected 21.8% of trees. The canker causing pathogens that were isolated the most were Cadophora luteo-olivacea and Diplodia seriata. A low incidence of wood rot fungi was found with only 1.5% of nursery trees infected. In total 26 new reports of fungal species on stone fruit in South Africa were made. Of these, 22 have not been found on stone fruit world-wide. The pathogenicity trials’ results confirmed the pathogenic status of these newly reported species. All of the isolates tested formed lesions significantly longer than the control, 4 months after wound inoculation of 2-year-old shoots of two plum orchards. Lasiodiplodia theobromae was the most virulent species on both plum cultivars. The results of this research showed that nursery stone fruit trees and propagation material can harbor latent infections. Different management practices need to be evaluated to prevent these infections to ensure healthier stone fruit nursery trees.

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