Multienvironment Performance of New Orange‐Fleshed Sweetpotato Cultivars in South Africa

Abstract

Vitamin A deficiency is a serious health problem in South Africa, as in several parts of the world. One strategy to combat micronutrient deficiency is through biofortification, particularly through orange‐fleshed sweetpotato [Ipomoea batatas (L.) Lam]. Previously, a shortage existed in South Africa of orange‐fleshed genotypes with a combination of high dry mass, good yield, and good taste. Local cream‐fleshed parents and orange‐fleshed US introductions were used in the local polycross program. This study aimed at testing the agronomic performance, stability, and genetic diversity of newly developed orange‐fleshed genotypes. Twelve entries, nine with orange flesh color, were evaluated at four sites for two seasons in multienvironment trials and the data was subjected to ANOVA and genotype plus genotype‐by‐environment interaction (GGE) biplot analysis. Simple‐sequence repeat (SSR) analysis of the 12 entries was done followed by hierarchical clustering. Two of the orange‐fleshed cultivars were recommended for production and plant breeders’ rights were registered for these. Cultivar Impilo produced stable, high root yield similar to the commercial control cultivar Beauregard; while the elite breeding line Purple Sunset (2001_5_2) had high yield and specific adaptability. Both displayed average dry mass and acceptable taste. The genetic analysis indicated relatedness of most new genotypes with the cream‐fleshed parents used in the polycross program. The improved cultivars offer considerable yield advantage above US introductions previously recommended for combating vitamin A deficiency.

On-farm multi-location evaluation of genotype by environment interactions for seed yield and cooking time in common bean

“…However, there is limited information on studies conducted on farms owned and managed by the common bean growers 8 . On-farm participatory evaluation of genotype and genotype by environment interactions can identify novel germplasm suited for specific agro-ecological conditions, as previously demonstrated for rice in India 9 , sweet potatoes in Uganda and South Africa 10,11 , and cassava in Tanzania 12 . Genotypic yield performance is influenced by multiple genes interacting with biotic and abiotic stress factors over the course of the crop's growing evaluation of Genotype and environment performances Agronomic traits.…”

Biofortified Crops for Combating Hidden Hunger in South Africa: Availability, Acceptability, Micronutrient Retention and Bioavailability

“…Production of the OFSP is being supported by the Agricultural Research Council (ARC) Vegetable and Ornamental Plant Institute (ARC-VOPI) [ 60 ]. Breeding of OFSP in South Africa started in 1996, with sweet potatoes containing adequate concentrations of β-carotene [ 61 ].…”

“…They ascribed these finding to variations in soil mineral content, soil pH and the interaction of these factors [ 68 ]. A study was conducted by [ 61 ] in South Africa to assess the agronomic ability, stability and genetic diversity of recently developed OFSP genotypes. This included the evaluation of twelve entries, nine of which had an orange flesh colour, at four sites for two seasons in multi-environment trials.…”

Genotype × Environment Interactions for East African Orange‐Fleshed Sweetpotato Clones Evaluated across Varying Ecogeographic Conditions in Uganda

“…The crop has often been considered as a subsistence crop for marginal conditions and usually ignored for its nutritional value (Woolfe, 1992) and breeding potential (Grüneberg et al, 2009b). Nowadays, there is increasing information about (i) the worldwide public health problems related to vitamin A, Fe, and Zn deficiencies in our food supply (Low et al, 2001, 2007; Pfeiffer and McClafferty, 2007;), (ii) the extreme high provitamin A content and substantial root Fe and Zn content in high‐yielding OFSP cultivars (Mwanga et al, 2007; Laurie et al, 2012; Grüneberg et al, 2009b; Tumwegamire et al, 2011a), and (iii) the genetics and new cultivars of sweetpotato such as the new DS OFSP type (Mwanga et al, 2007; Grüneberg et al, 2009a; Tumwegamire et al 2011a,b; Laurie et al, 2015).…”

“…The CIP and partners are breeding for DS OFSP cultivars in a decentralized breeding approach, which means (i) local parental selection, (ii) intensive recombination, and (iii) selections considering farmer and gender sensitive attributes (i.e., SPVD resistance, sufficient upper biomass production, dry mouth feel, and not too sweet taste [Grüneberg et al, 2009b]). Owing to the close genetic relation among African WFSPs and locally found or bred OFSPs, as well as large genetic distances between American and African OFSP germplasm (Tumwegamire et al, 2011b; Laurie et al, 2015), it is hypothesized that African DS OFSP cultivars are sufficiently genetically diverse to show pronounced G × E patterns similar to those observed by Grüneberg et al (2005) for a diverse set of clones comprising WFSP and traditional OFSP evaluated across varying ecogeographic conditions of Peru. A better understanding of G × E interactions in DS OFSPs in eastern and central Africa (ECA) is required before breeders can confidently decide (i) whether a breeding platform can serve the ECA subregion to conduct population improvement for DS OFSP in ECA and (ii) which locations should be chosen for breeding in early or later breeding stages.…”