Indigenous knowledge, variation in morphology, nutritional composition and genetics of Strychnos spinosa morphotypes

Strychnos spinosa Lam., commonly known as green monkey orange (English) and umHlala (isiZulu), belongs to the Loganiaceae family. It is of African origin, and in South Africa it grows predominantly in the Eastern Cape, Limpopo, KwaZulu-Natal, and Mpumalanga provinces. It is used for food, medicine and to improve the socio-economic status of rural communities. However, studies on indigenous knowledge, variation in morphology, nutritional composition, and genetics among S. spinosa morphotypes are limited. Thus, this study aimed to determine the indigenous knowledge, variation in morphology, nutrition, and genetics among S. spinosa morphotypes. Local indigenous knowledge on S. spinosa was documented from Oyemeni community in KwaZulu Natal, whereas variation in morphology, nutritional and genetic analysis were assesed from morphotypes at Bonamanzi Game Reserve in Northern KwaZulu-Natal. Indigenous uses of S. spinosa included direct fruit consumption; development of local and nutrient dense food products and drinks, such as fermented maize meal (umBhantshi), fermented porridge (amaHewu), alcohol, juice, and jam; various medicines; as well as for homestead protection, livestock increase and firewood. Oyemeni community gave the first report on umBhantshi preparation from S. spinosa, and indigenous knowledge on the morphological and organoleptic variations that exist within S. spinosa. Apparently, the whole study was the first evidence of variation among S. spinosa morphotypes based on morphological, nutritional, and genetic traits. This also included the first report on the existence of purple, pyriform, and rough fruits, as well as a purple tint on the juvenile leaves. Fruit and seed traits, as well as calcium, phosphorus, magnesium, copper, iron, manganese, fat, acid detergent fibre, neutral detergent fibre, sodium and crude protein nutrient, were the important traits used to determine variation among S. spinosa morphotypes, based on principal component analysis. In cluster analyses, morphotypes GRR-dGEO, GRxCP-GEF, GvRxCR-GEF, GRxCP-dGEF, PRR-dGRF, PRxCP-GEO, GvRR-dGEO, GvRR-GRO, GRxCR-dGEF, and GRxCR-dGEO were associated based on their rough pericarp texture, small-sized fruits, high nutrient content in fruits, and related genetic attributes. These morphotypes can be recommended for future breeding, domestication, use in various food products and commercialisation practices. This study also reported the first development and successful use of simple sequence repeat markers for genetic diversity and population structure of S. spinosa. Results on diversity in morphology and genetics of S. spinosa morphotypes can be used to improve these fruit species for commercialisation and enhanced food security, as they have a nutritional profile that is above well-known commericial fruits.
Theses submitted to the Faculty of Science, Agriculture and Engineering in fulfilment of the requirements for the degree of Doctor of Philosophy in the Department of Botany at the University of Zululand