Agronomic Performance, Nutritional Phenotyping and Trait Associations of Okra (Abelmoschus esculentus) Genotypes in South Africa

Okra, Abelmoschus esculentus L. (Moench), is an important fruit vegetable crop which belongs to the family Malvaceae. It is a good source of protein, carbohydrates, vitamins, minerals, and enzymes that are often consumed in small quantities in developing country. Okra is a highly nutritious underutilized fruit vegetable crop in South Africa. However, despite its importance for food, nutritional, and health benefits, the crop is rarely produced in some areas of South Africa. The study was carried out to assess the genetic diversity using agro-morphological traits and nutritional contents towards future use in the okra breeding programme. The experiment was carried out at the Roodeplaat research farm of the Agricultural Research Council in a randomized complete block design replicated three times. Agro-morphological traits and selected nutrients were determined. The analysis of variance for both showed highly significant differences for most traits recorded. The multivariate analysis showed a wide genetic diversity among the okra genotypes, which could be exploited in selecting suitable and potential parents when breeding for high yield and nutritional qualities. The present study revealed the genetic potential of the genotypes studied and their importance for use in the breeding programme aimed toward addressing malnutrition, food security, and poverty alleviation by breeding for increased yields, and nutritional contents in South Africa

Draft genome sequence of Alternaria alternata isolated from onion leaves in South Africa

Alternaria alternata (Fr.) Keissler strain PPRI 21032 was isolated from onion leaves collected in Roodeplaat, Pretoria, South Africa. The whole genome of this strain was sequenced and produced a total of 33.12 Mb with a GC content of 50.9%. The whole genome comprises 11,701 predicted coding sequences.The Agricultural Research Council (ARC) of South Africa and the World Vegetable Center core donors [Republic of China (Taiwan), UK Department for International Development (DFID), United States Agency for International Development (USAID), Australian Centre for International Agricultural Research (ACIAR), Germany, Thailand, Philippines, Korea, and Japan].http://genomea.asm.orgam2017Forestry and Agricultural Biotechnology Institute (FABI)Microbiology and Plant Patholog

Characterisation of agro-morphological traits of corchorus accessions

http://www.tandfonline.com/loi/sagb202019-09-03hj2018Plant Production and Soil Scienc

Strengthening farmer-managed seed systems in South Africa

This report presents field activities carried out in the period 2019-2022 in support of farmer-managed seed systems in South Africa, in particular the conservation efforts and participatory variety selection (PVS) carried out by the community seed banks of Gumbu, Jericho and Sterkspruit. The PVS was done on four priority crops selected by the farmers, cowpea, okra, pearl millet and sorghum, with the support of DALRRD and the Agricultural Research Council - Vegetable, Industrial and Medicinal Plants (ARC-VIMP; formerly ARC-VOPI) campus at Roodeplaat (Gauteng), and the ARC-Grain Crops (ARC-GC) campus at Potchefstroom (North West Province). The report also presents a synthesis of results achieved since the start of the activities and identifies challenges encountered

Preliminary study on variability and heritability estimates of micronutrient composition in the immature fruits of okra (Abelmoschus esculentus) genotypes in South Africa

Okra is one of the important fruit vegetable crop but is an under-utilized and neglected plant species in South Africa. The immature fruits of okra is a good source of protein, minerals and vitamins. Despite its contribution to food, nutritional and health security, this crop is rarely cultivated and researched in South Africa. The study was carried out to assess the genetic variability and heritability estimates using micronutrient content such as iron, zinc and manganese in the immature green fruits of okra plant for future use in the okra breeding programme to increase nutritional value. The experiment was conducted at the Roodeplaat research farm of the Agricultural Research Council in a randomized complete block design replicated three times. The analysis of variance showed highly significant differences for all of three micronutrients recorded. This indicated that there were high level of genetic differences among the genotypes studied. Phenotypic and genetic coefficient of variations, broad-sense heritability (repeatability) and genetic advance were also estimated for iron, zinc and manganese, which could be exploited in selecting suitable and potential okra parents when breeding for high micronutrient contents. The phenotypic coefficient of variation ranged from 23.04% in Zn to 75.48% in Fe. Furthermore, the highest values for the genetic coefficient of variation was found in Fe. High heritability estimates were observed in all mineral elements Fe (99.86%), Mn (99.72%) and Zn (96.32%) evaluated indicating potential genetic gain as percentage of mean for Fe (155.38), Mn (69.20) and Zn (45.79), respectively when breeding for these micronutrient traits. The present study revealed the genetic potential of the genotypes studied and their importance for use in the quality-breeding programme aimed towards addressing malnutrition in South Africa

Efforts in breeding cowpea for aphid resistance: a review

Cowpea is an important food and nutritional security grain legume crop in the semi-arid regions of sub-Saharan Africa. Its production is limited by biotic factors including pre-harvest insect pests such as aphids. Aphids cause yield reductions, promotes the growth of sooty moulds, honeydew and as a result reduce photosynthetic processes and rates. Various methods have been deployed to try to control the damage of aphids in cowpea plants. The methods include the use of chemical insecticides, cultural, mechanical, biological controls and integrated pest management. However, these methods have not been very effective as smallholder farmers growing cowpea in marginal areas cannot afford them. Hence, host plant resistance/genetic control is the best and effective method for controlling aphids in cowpea plantations. Breeding for aphid resistance is one of the effective methods that can sustain the production and productivity of the cowpea for longer periods. Furthermore, assessing the presence of genetic diversity can also help in sourcing genes of novelty for addressing this important issue to increase the production and productivity of the crop. Recently, scientists have used various strategies to try to solve the challenge of aphid damage on cowpea. The objective of this review was to document the research progresses on aphid resistance breeding of cowpea to facilitate the breeding and conservation of cowpea germplasm. The review serves as a baseline information to guide future cowpea breeding for resistance to aphids

Bambara Groundnut (Vigna subterranea [L.] Verdc.) Production, Utilisation and Genetic Improvement in Sub-Saharan Africa

Bambara groundnut (Vigna subterranea [L.] Verdc.) is a nutritionally rich grain legume crop indigenous to Africa. It is tolerant to drought stress and has become adapted to grow under low input and marginal agricultural production systems in Africa and Asia. Bambara groundnut is an orphan crop, and represents a neglected and under researched plant genetic resource. Modern crop management, production technologies, and value chains are yet to be developed in Africa to achieve the potential economic gains from Bambara groundnut production and marketing. In sub-Saharan Africa (SSA) the production and productivity of Bambara groundnut is low and stagnant because of diverse abiotic and biotic stresses and socio-economic constraints. Improved crop management and post handling technologies, modern varieties with high yield and nutritional quality, value addition, and market access are among the key considerations in current and future Bambara groundnut research and development programs. This paper presents progress on Bambara groundnut production, utilization, and genetic improvement in SSA. It presents the key production constraints, genetic resources and analysis, breeding methods and genetic gains on yield, and nutritional quality and outlook. The information presented will guide the sustainable production and effective breeding of the crop in order to pursue food and nutrition security, and improve livelihoods through Bambara groundnut enterprises

Expression of Nutritional Traits in Vegetable Cowpea Grown under Various South African Agro-Ecological Conditions

Cowpea (Vigna unguiculata L.), a traditional legume food crop indigenous to Africa, has potential as both a vegetable and grain crop in contributing to dietary diversity to support health and address malnutrition, especially for those relying heavily on wheat, maize, and rice. The expression of nutritional traits (protein content and concentrations of iron (Fe), zinc (Zn), and manganese (Mn)) in cowpea leaves was evaluated over diverse agro-ecologies of South Africa and typical agronomic practices of smallholder farmers. The genotypes evaluated displayed genetic variation for all four traits. The mean values of Fe, Zn, Mn and protein content varied from 33.11 to 69.03 mg.100.g−1; 4.00 to 4.70 mg.100.g−1; and 14.40 to 19.63 mg.100.g−1 and 27.98 to 31.98%, respectively. The correlation analysis revealed significant degree of positive association between protein and Zn (r = 0.20), while negative associations were observed between Mn and protein (−0.46) and between Mn and Fe (r = −0.27). Furthermore, the expression of these important nutrient traits was influenced by the climatic conditions represented by six environments (location by year combinations) as is typical of ‘quality’ traits. Additionally, genotype-by-environment interaction effects were detected, suggesting that local soil properties and soil health may play a role in nutritional content in plants, perhaps particularly for legume crops that rely on symbiotic relationships with soil bacterial populations to fix nitrogen, which is crucial to protein formation. Further studies are needed to understand how to coordinate and align agronomic and soil management practices in vegetable cowpea production, especially those workable for the smallholder farmer, to realize the full genetic potential and nutritional value of improved vegetable cowpea varieties