Comparative evaluation of the germination capability of three morphologically different wild genotypes of Corchorus olitorius L. from Northern KwaZulu-Natal, South Africa

Corchorus olitorius L. is a wild plant utilised as a vegetable in many parts of Africa. Wild indigenous vegetables have been recommended to alleviate nutritional deficiencies and household food insecurity. Efforts to domesticate and cultivate wild C. olitorius and other wild vegetables are being hampered by seed dormancy. The main cause of dormancy in C. olitorius has been suggested to be an impermeable seed coat. This study evaluates the response of wild genotypes of C. olitorius with different seed sizes to various dry heat and hot water treatments. Steeping seeds in boiling water (95°C) for 10 s and soaking seeds in a hot water bath at 80°C for 10 min resulted in a highest response to germination in the tested genotypes of this species. The study also recorded significant interactions between heat treatment and seed sizes. It was therefore concluded that genotypes of C. olitorius with different sizes require diverse durations of exposure to heat treatment methods to break dormancy caused by an impermeable seed coat.Key words: Corchorus olitorius, genotypes, germination, heat treatment, wild vegetables species

Cyclopia subternata growth, yield, proline and relative water content in response to water deficit stress

Cyclopia, generally known as honeybush, and belonging to the Fabaceae family, originates from the Cape Floristic Region of the Eastern Cape and Western Cape provinces of South Africa. Currently, 6 honeybush species are commercially cultivated but, to date, there have been limited trials attempting to study their agronomic water demand. A pot trial was conducted where Cyclopia subternata plants were cultivated on different soil types (Stellenbosch granite, Stellenbosch shale and Stellenbosch clovelly) and subjected to three different water-deficit stress levels (well-watered, semi-stressed and stressed). Remarkably, irrigation treatments and soil types did not significantly affect the growth of the plants. However, the well-watered treatment consistently had higher yields compared to the other two treatments. The water-stressed (semi-stressed and stressed) treatments had lower relative water contents (RWC) with higher concentrations of proline, which signify water stress, compared to the control treatment. Higher proline and lower RWC contents found in this study are indications of water stress

Clonal propagation of Pelargonium sidoides: A threatened medicinal plant of South Africa

Pelargonium sidoides is used in herbal medicine for the treatment of various infections. Apart from the local uses, the roots are being indiscriminately harvested for local and export trade. A study was conducted to determine the appropriate plant part and the minimum vine length suitable for the clonal propagation of P. sidoides in two separate experiments. In the first experiment, three vine tip cuttings (2, 4 and 6 cm) of the species were rooted in potted experiment in a green house. In the second experiment, ten days old petioles were excised from their mother plants and rooted along side 6 cm vines length to assess suitable plant part for vegetative propagation of the species. Data were collected and analyzed on various growth and development indices. In the first experiment, the 6 cm vine length exhibited best result for different parameters measured. Petioles gave significant yield difference over 6 cm vine length and generally showed high potential for vegetative propagation in terms of rooting ability and survival rate. The importance of these findings on the propagation and conservation of P. sidoides is discussed.Keywords: Clonal propagation, ex situ conservation, medicinal plant, Pelargonium sidoides, stem cuttin

Cyclopia subternata growth, yield, proline and relative water content in response to water deficit stress

Cyclopia, generally known as honeybush, and belonging to the Fabaceae family, originates from the Cape Floristic Region of the Eastern Cape and Western Cape provinces of South Africa. Currently, 6 honeybush species are commercially cultivated but, to date, there have been limited trials attempting to study their agronomic water demand. A pot trial was conducted where Cyclopia subternata plants were cultivated on different soil types (Stellenbosch granite, Stellenbosch shale and Stellenbosch clovelly) and subjected to three different water-deficit stress levels (well-watered, semi-stressed and stressed). Remarkably, irrigation treatments and soil types did not significantly affect the growth of the plants. However, the well-watered treatment consistently had higher yields compared to the other two treatments. The water-stressed (semi-stressed and stressed) treatments had lower relative water contents (RWC) with higher concentrations of proline, which signify water stress, compared to the control treatment. Higher proline and lower RWC contents found in this study are indications of water stress