native South African woody plants. These are the myrtle rust pathogen, Puccinia psidii, and the cycad aulacaspis scale (CAS), Aulacaspis yasamutsii. Both these organisms most likely entered the country on non-native plants, possibly linked to the nursery trade. Despite quarantine efforts and other plant protection strategies, these and other pests continue to enter the country. While this is not unexpected due to the magnitude of the task, it is of great concern that there is almost no action post entry to deal with non-native pests and pathogens. Without the active involvement of all plant and conservation specialists, enthusiasts, scientists and the government, South Africa faces potentially devastating loss of iconic native and other woody plants. Indeed we might expect the transformation of entire ecosystems as has occurred elsewhere in the world. doi:10.1016/j.sajb.2015.03.116
The effects of elevated copper and zinc concentrations on hydroponically cultivated soybean (Glycine max [L Merr]) at the vegetative growth stage
Gerbera L. is a genus of perennial herbs commonly known as Barberton daisies and comprises about 29 species, 13 of which occur in southern Africa. The genus is placed within the largely South American tribe Mutisieae and, together with Perdicium, are the only African members within this early diverging lineage. Recent phylogenetic analyses place Gerbera sister to the Leibnitzia, a genus of six species found in America and Asia. However, its putative close relative Perdicium has not been included in any phylogenetic studies to date. The African species of Gerbera were last monographed by Hansen in 1985 who divided them into four sections (Parva, Piloselloides, Lasiopus and Gerbera). Section Gerbera is endemic to the Cape Floristic Region of South Africa and consists of approximately ﬁve perennial species with bracteate scapes and shortly beaked achenes with obtuse or inﬂated hairs. However, two undescribed species from this section have since come to light and need to be formally described, and the keys and distribution data for the species of section Gerbera as a whole revised. The monophyly of sect Gerbera and the phylogenetic placement of Perdicium will be also assessed, using an expanded sampling of the Mutisieae, based on analyses of nrITS, rpl32 and trnL-F sequences.
P.M. Sepadi, P.W. Mokwala, R.V. Nikolova, H.J. Du Plessis, F. Nukeri Department of Biodiversity, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa
Pollution and subsequent contamination of the environment with heavy metals are generated by mining and smelting activities, long term use of heavy metal containing fertilisers, sewage sludge application and waste water irrigation in agricultural lands. Soybean is an important agricultural crop, which has been reported to accumulate high concentrations of heavy metals when grown in contaminated areas, without showing any visible symptoms. In this study we determined the effects of elevated concentrations of copper and zinc on the photosynthetic pigments, phenolic compounds, stomata structures and plant growth on hydroponically grown soybeans. Plants treated with 100 μM and 150 μM copper showed severe symptoms such as chlorosis, necrosis and death of aerial parts which were metal concentration and duration of exposure dependant. Zinc treated plants did not show any symptoms or reduction in growth and biomass production. Increased carotenoid and phenolic compounds contents were observed in plants treated with 50 μM copper and 200 μM, 250 μM and 300 μM zinc, where minimal to no foliar symptoms were observed. Stomatal density was signiﬁcantly increased in the higher metal concentration treatments. These ﬁndings are important for understanding how cultivating this crop in contaminated areas affects its physiological function and subsequently its yield and quality.
Ecological associations between leaf domatia and mites: How does the mutualism work?
A review of the taxonomy and phylogenetic relationships of Gerbera section Gerbera (Asteraceae: Mutisieae) in the Cape Floristic Region a
S. Situngu, N. Barker Department of Botany, Rhodes University, PO Box 94, Grahamstown 6140, South Africa Leaf domatia, plant produced cavities usually found in the axils of major veins in the abaxial side of leaves, are usually associated with mites and mediate mutualistic relationships with predacious mites. In plants, mites inhabit leaf domatia for shelter and to reproduce and develop. In turn, the plants beneﬁt from increased defense against pathogens and small arthropod herbivores. The aims of this study were to generate a better understanding of the ecological patterns of mites found within leaf domatia from an African perspective. Here we report on three aspects of mite diversity and ecology. Firstly, a survey of plant species that possess leaf domatia from Eastern Cape forests was collected and examined. The majority of mites found within the domatia of these tree species are predaceous mites from the families Tydeidae and Phytoseiidae. However, Phatophagous (Tethranychidae) and even saprophytic species (Oribatei) were also found. Secondly, seasonal ﬂuctuations in mite abundance and diversity over time were observed, and thirdly, an assessment of mite occupation throughout the tree canopy suggests that mites may prefer older leaves found in the lower regions of the tree canopy and avoid young leaves at the top. This study contributes to a better understanding of the mutualisms association between plants and mites from an African perspective. doi:10.1016/j.sajb.2015.03.119
B. Simka , J.S. Boatwright , A.R. Magee , J.C. Manning a Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville, Cape Town, South Africa b Compton Herbarium, South African National Biodiversity Institute, Private Bag X7, Claremont 7735, Cape Town, South Africa c Department of Botany and Plant Biotechnology, University of Johannesburg, PO Box 524, Auckland Park 2006, Johannesburg, South Africa d Research Centre for Plant growth and Development, School of Life Sciences, University of KwaZulu Natal, Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa
Ethnobotanical survey of plants used by rural people in the Eastern Cape to control ﬁeld arthropod pests of maize N. Skenjanaa,b, A.J. Afolayanb a Directorate of Plant and Crops Production Research, Döhne Agricultural Development Institute, Private Bag X15, Stutterheim 4930, South Africa b Department of Botany, Faculty of Science and Agriculture, University of Fort Hare, Alice 5700, South Africa
Arthropod pests can cause substantial damage to the maize plant resulting to yield losses of up to 100%. Rural farmers often do not afford the costs of chemical insecticides; alternatively they tend to use indigenous pest control methods which include the use of plants. An ethnobotanical survey of plants used in the Eastern Cape by farmers to control ﬁeld pests of maize was conducted in 14 different towns under 5 district municipalities from 217 rural small-scale farmers. Data were analysed using descriptive statistical methods. Findings revealed that some of the farmers were knowledgeable of indigenous pest control methods to manage pests of maize and as a result they applied them. This information was found to reside with few elderly people of which majority were females. Although, most of the plants cited were from families Solanaceae and Asteraceae, the most preferred was Chenopodium ambrosioides, a perennial herb from the family Chenopodiceae. The largest percentage of plants used was mainly those harvested from the wild and were mostly herbs. In making formulations, respondents commonly used leaves and most of the preparations were applied on the whole plant using different modes of application. It may be possible that not all the plants mentioned by participants can control target pests. These ﬁndings, however, raise a need for a continuous validation and documentation of indigenous pest control methods thus bridging the generational gap. Further research on these methods may play a signiﬁcant role in reducing costs associated with insect pest control in crop production. doi:10.1016/j.sajb.2015.03.120
Effects on fungicide application on sorghum yield, leaf senescence and photosynthetic efﬁciency in South Africa K. Smitha, M. Cravena, N.W. McLarenb, J.M. Bernerc a Agricultural Research Council — Grain Crops Institute, Private Bag X1251, Potchefstroom 2520, South Africa b Department of Plant Sciences, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa c Research Unit for Environmental Sciences and Development, North West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520, South Africa Sorghum (Sorghum bicolor (L.) Moench & Suggs) is one of the ﬁve most widely cultivated grasses in Sub-Saharan Africa. Sorghum is under constant threat of biological attack by pathogens. Exserohilum turcicum is a fungal foliar pathogen causing leaf blight (LB) on all major cultivated grasses and losses of up to 50% have been recorded on sorghum. Certain fungicidal compounds, such as triazoles, have been shown to have plant growth regulating properties leading e.g. to increased yield and delayed leaf senescence. The merit of these growth regulating properties of fungicides has not been evaluated under various climatic conditions within South Africa. Three split plot trials were accordingly planted (Potchefstroom, Standerton and Greytown) during 2013/14. Eleven fungicide treatments (main plots) were applied consisting of two fungicides (Azoxystrobin/ Difenoconazole and Epiconazole/Pyraclostrobin) applied on ﬁve different dates (6 weeks, 6 and 8 weeks, 8 weeks, 8 and 10 weeks and 10 weeks after planting). Four cultivars (sub-plots) were included (PAN8816, PAN8906, PAN8911 and NS5511). Yield (12.5% moisture, harvest), leaf senescence at harvest (S1), two (S2), and four (S3) weeks post-harvest, as well as chlorophyll a ﬂuorescence at harvest (P1), two (P2), and four (P3) weeks post-harvest measurements were obtained from each locality. Yield response to the various treatments differed between localities, with Azoxystrobin/ difenoconazole treatment applied at 8 and 10 weeks resulting in signiﬁcant higher yield as opposed to the control at the Standerton area. Effect on senescence was locality speciﬁc, with fungicide application
resulting in delayed senescence in the Greytown area. The various treatments had an impact on the photosynthetic efﬁciency (PE) of speciﬁc cultivars two weeks after harvest (P2) resulting in higher PE in some cultivars as opposed to their respective controls, but also in some cases lower PE. These results show that the effect of fungicide application on sorghum may be cultivar and locality speciﬁc. doi:10.1016/j.sajb.2015.03.121
A review of chemosystematic patterns in African Apiaceae O. Sobiyi, A.R. Magee, B.-E. Van Wyk Department of Botany and Plant Biotechnology, University of Johannesburg, PO Box 524, Auckland Park, 2006 Johannesburg, South Africa Recent studies on the African members of the family Apiaceae/ Umbelliferae have shown that a large percentage of African endemic genera are basally divergent within the subfamily Apioideae. These predominantly woody and anomalous taxa are crucial in understanding the early evolution and diversiﬁcation within the subfamily. Molecular systematic studies have recently provided the ﬁrst rigorous phylogeny against which the chemical patterns can be compared and interpreted. This is a unique scientiﬁc opportunity to gain insight into the early chemical diversiﬁcation of an important plant family. Very few African genera and species have hitherto been studied. A literature review will be presented, showing the need for detailed chemosystematic studies of the family in Africa and especially the subfamily Apioideae sensu lato. The known patterns of distribution of phenolic compounds, terpenoids and alkaloids will be presented and interpreted within the framework of the most recent molecular phylogeny. doi:10.1016/j.sajb.2015.03.122
Phylogenetic hypothesis for the southern African genus Tulbaghia L. (Amaryllidaceae, Allioideae) based on plastid and nuclear DNA sequences G.I. Stafforda, N. Rønstedb a Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa b Natural History Museum of Denmark, University of Copenhagen, Sølvgade 83S, DK-1307 Copenhagen, Denmark Southern Africa has representatives of three indigenous genera in the subfamily Allioideae (Amaryllidaceae), Allium L., Tulbaghia L. and Prototulbaghia Vosa. The distribution of Allium is almost entirely North American/Eurasian with the occurrence of a single species in South Africa. However, Tulbaghia which comprises 20–30 species; and the recently described monospeciﬁc genus Prototulbaghia (Vosa, 2007) contain the remaining South African Alliacious species. There have been several conﬂicting taxonomic treatments of the group and considerable confusion persists. These will be reviewed and presented alongside a phylogenetic hypothesis based on 176 new sequences (for ITS, trnLF and ndhF) produced for this study and 36 sequences, mostly for the outgroup, downloaded from EMBL/GenBank. In the combined analysis Prototulbaghia siebertii is sister to a clade containing Tulbaghia cernua, Tulbaghia ludwigiana and Tulbaghia simmleri. Sister to P. siebertii is a large clade containing the remaining species except for Tulbaghia montana and Tulbaghia dregeana, suggesting that it is most likely not a separate genus. doi:10.1016/j.sajb.2015.03.123