Julia Sibiya

University of KwaZulu-Natal | ukzn · African Centre for Crop Improvement

Development of stable, high yielding and micronutrient dense bean cultivars offers a sustainable solution to the challenge of malnutrition in developing countries. The objectives of this study were to evaluate the effects of genotypes, environments and genotype by environment (GEI) on iron (Fe) and zinc (Zn) in grain and grain yield (GYD) in navy b...

Drought is a major threat to banana production in Uganda, leading to large yield losses. This study documented drought effects on banana production and identified farmers’ drought mitigation strategies. Interviews were conducted in eight districts, randomly selected from banana-growing districts in Uganda’s cattle corridor, characterised by frequen...

Citron watermelon (Citrullus lanatus var. citroides) is an extremely drought-tolerant cucurbit crop widely grown in sub-Saharan Africa in arid and semi-arid environments characterized by drought. The species is a C3 xerophyte used for multiple purposes, including intercropping with maize and has a deep taproot system. The deep taproot system plays...

Spider plant ( Gynandropsis gynandra (L.) Briq .) is among the most important African Leafy Vegetables (ALVs) as a source of essential nutrients with the potential of contributing significantly to household food and nutritional security and mitigation of hidden hunger. Nevertheless, the vegetable is considered an orphan crop and its production is c...

Navy beans (Phaseolus vulgaris L.) are an important food and cash crop for export from countries such as Myanmar, United States of America (USA), Ethiopia, China, Canada and Argentina to lucrative markets in north America, Middle East, southern Africa and eastern Europe. Knowledge of the genetic basis of navy bean performance under drought stress (...

Bambara groundnut (Vigna subterranea (L.) Verdc) is a nutritious and drought-tolerant crop that is native to Africa. Currently, it possesses a cosmopolitan distribution across the semi-arid agro-ecologies of Africa and its cultivation has extended to other regions, particularly in the drier parts of Asia and Indonesia. Due to historic neglect, rese...

The past decades have seen the implementation of several multi-national maize and common bean cultivar development projects in sub-Saharan Africa (SSA). However, the impacts of these projects on income generation and food and nutrition security have not been adequately interrogated and documented. This chapter provides a synthesis of some of the pa...

Navy bean (Phaseolus vulgaris L.) provides important raw materials for the bean canning industry. This article reviews grain compositional aspects influencing the canning and quality attributes of canned navy beans and breeding methodologies and strategies used to develop genotypes with superior canning quality traits. Cultivars that are destined f...

Knowledge of the genetic basis of navy bean ( Phaseolus vulgaris L.) performance under drought stress (DS) is important for planning appropriate breeding and selection strategies in DS environments. Twenty-eight F 2 progenies generated from an 8 x 8 half-diallel mating design were evaluated to determine combining ability effects and mode of gene ac...

Dry bean (Phaseolus vulgaris L.) is a key protein and income source grown worldwide. This study determined gene effects influencing resistance to the bacterial brown spot (BBS) disease caused by Pseudomonas syringae pv. syringae, and estimated heritability in a dry bean cross between A55 (resistant) and cultivar RS7 (susceptible). Generations deriv...

Despite the growing interest in the miracle plant worldwide due to its numerous applications, the threats and the wild harvest of the species hamper its sustainable utilisation. Moreover, traditional knowledge so far documented on the species is limited to a narrow geographical coverage of its natural distribution range, which is West and Central A...

Bruchids are a major storage pest of common bean. Genetic resistance is a suitable method to avoid grain losses during storage. The objective of the study was to introgress the arcelin-based resistance locus into selected advanced breeding line and to validate the molecular marker BRU_00261. A total of 208 progeny F4 families were phenotyped using...

Drought is a major threat to banana production in Uganda, leading to large yield losses. This study documented drought effects on banana production and identified farmers’ coping strategies to mitigate the impact of droughts. Interviews were conducted in eight districts, randomly selected from banana-growing districts in Uganda’s cattle corridor, c...

Assessment of genetic purity of parental inbred lines and their resultant F 1 hybrids is an essential quality control check in maize hybrid breeding, variety release and seed production. In this study, genetic purity, parent-offspring relationship and diversity among the inbred lines were assessed using 92 single-nucleotide polymorphism (SNP) marke...

This study aimed to understand the outcomes of farmers' as well as breeder's or metric criteria for selection of preferred groundnut varieties in Uganda. The study further assessed whether the intersection of these approached could be exploited for local breeding efforts and therefore enhance breeding efficiency

Background Understanding end-users’ preferred breeding traits and plant management practices is fundamental in defining sound breeding objectives and implementing a successful plant improvement programme. Since such knowledge is lacking for Synsepalum dulcificum , a worldwide promising orphan fruit tree species, we assessed the interrelationships a...

Breeding for drought tolerance in plants is challenging because it is controlled by multiple genes. Grain yield, the trait of primary interest in maize, is characterized by low heritability, high genotype by environment interaction, and low variation under drought conditions, which further complicates selection. To circumvent these challenges, seco...

Assessment of genetic purity of inbred lines and their resultant F 1 hybrids is an essential quality control check in maize hybrid breeding, variety release and seed production. In this study, genetic purity, parent-offspring relationship and diversity among the inbred lines were assessed using 92 single-nucleotide polymorphism (SNP) markers. A tot...

Roots are key organs for water and nutrient acquisition and transport. Therefore, root phenes that are associated with adaptation to low phosphorus (P) environments could enhance top-soil exploration, while deeper allocation is important for acquiring water and mobile nutrients. The understanding of interactions among root phenes can help in the de...

Background Navy bean is an important legume crop in Zimbabwe. Although its production in Zimbabwe is limited by multiple constraints including biotic, abiotic and socio-economic, there is no documented evidence. Thus, this study aimed at identifying farmers’ production constraints, preferred traits and cultivars of navy bean, and strategies used to...

Aluminium toxicity in acidic soils (Al) and the maize streak virus disease (MSV) cause significant losses in maize productivity. These constraints can occur simultaneously in sub-Saharan Africa but there are no maize hybrids that combine resistance for both stresses. Therefore, the objectives of the study were to determine combining ability, gene a...

Maize breeding programmes exploit inbred lines with superior combining ability for grain yield and other agronomic traits to create competitive hybrids. Therefore, the objectives of this study were to determine heterotic groups of locally developed maize inbred lines, their heterotic relationships, with exotic testers as well as the gene action con...

Background: Navy bean is an important legume crop in Zimbabwe. Its production is limited by multiple constraints including biotic, abiotic and socio-economic. However, in the major navy bean-production regions of Zimbabwe, there is no recent study documenting biotic stress management strategies, farmers’ perceived production, and marketing constrai...

Understanding the genetic diversity present amongst crop genotypes is an efficient utilization of germplasm for genetic improvement. The present study was aimed at evaluating genetic diversity and population structure of 48 pigeonpea genotypes from four populations collected from diverse sources. The 48 pigeonpea entries were genotyped using 33 sim...

The miracle plant Synsepalum dulcificum is a multipurpose natural sweetener and a promising West African orphan fruit shrub candidate for genetic improvement. Unfortunately, basic knowledge such as phenotypic variation and inheritance estimates required for implementing a breeding program are still lacking. A set of 203 accessions were sampled in t...

Weevil damage caused by sweetpotato weevil (Cylas spp.) is a major constraint to sweetpotato production in Tanzania due to a lack of improved varieties with durable resistance. The objective of this study was to screen sweetpotato germplasm collections for weevil resistance and to select the best parents to be used in resistance breeding. Field stu...

The level of genetic diversity among the available breeding materials determines the potential success of a breeding program. In this study, 92 maize inbred lines were genotyped with 3047 single nucleotide polymorphism (SNP) markers using a Kompetitive Allele-Specific Polymerase chain reaction (KASPTM) genotyping protocol. The objectives were to de...

Breeding for resistance to late blight disease caused by Phytophthora infestans (Mont.) de Bary in potato is the most economically, effective and ecologically sustainable method to control the disease and boost productivity. The study estimated combining ability effects of yield, yield related traits, late blight resistance and gene action controll...

Development of high yielding and stable cultivars of various crops across the Southern African Development Community (SADC) member states is in line with the recently enacted SADC’s seed harmonisation act. This study, therefore, focused on evaluating soybean [Glycine max (L.) Merrill] lines developed by the International Institute of Tropical Agric...

Dry bean (Phaseolus vulgaris L.) is grown under an extensive range of agro-climatic conditions and is an essential source of protein and income globally. This study aimed to evaluate yield performance, stability, and bacterial brown spot (BBS) disease resistance of fourteen dark red kidney genotypes across environments in South Africa namely Caroli...

Spider plants (Gynandropsis gynandra, L. Briq.) are a semi-wild vegetable reported to have high nutritional, medicinal, insecticidal, and cultural values, yet continue to be neglected in research. The study was undertaken to investigate indigenous knowledge and utilization of the species in five regions of northern Namibia. Three tools were used; (...

This study was conductedto identify suitable parental genotypes for breeding for resistance to bruchid and to identify the farmers’ preferred traits incommon bean. For thisstudy, 144diverse common bean genotypes were planted in an alpha lattice design, with 3replications at 3locations. Participatory variety selectionwasdoneusing20farmers at each lo...

Understanding the mechanisms governing complex traits variation is a requirement for efficient crop improvement. In this study, the molecular characterization, marker-trait associations and the possibility for genomic selection in a collection of 281 Kersting's groundnut accessions were carried out. The diversity panel was phenotyped using an Alpha...

The objective of this study was to examine the genetic diversity present among 297 common bean genotypes using 2554 SNPs and 12 insects and seed-related traits. The phenotyping was done under laboratory condition while the genotyping was conducted by using the Illumina SNP BeadChip. High phenotypic diversity among traits were recorded, ranging from...

Bacterial brown spot (BBS) disease caused by Pseudomonas syringae pv. syringae is an important disease of dry bean (Phaseolus vulgaris L.), with grain yield losses of 55% reported in South Africa. This study aimed to identify BBS disease-resistant genotypes from 415 Andean Diversity Panel (ADP) dry bean lines and 5 check cultivars under field condi...

Groundnut production in East and South African region is low due to several constraints. Success in development of resilient varieties rides on genetic diversity in available germplasm for key traits in question. This study was undertaken to dissect the magnitude of variability among groundnut accessions. The experimental design was an alpha lattic...

Understanding the genetic control of Fusarium wilt resistance is crucial in pigeonpea breeding programme. This study aimed to study the gene action controlling Fusarium wilt resistance, yield and yield components and select promising crosses possessing resistance to Fusarium wilt along with important agronomic yield traits. Six lines were crossed w...

Background: Spider plant [Gynandropsis gynandra (L.) Briq.], an economically promising African leafy vegetable, characterized for leaf yield components and nutritive quality, exhibits poor seed germination that hinders a wider expansion of the crop in urban and periurban horticultural systems. So far, there is little information pertaining to seed...

Drought is a major abiotic stress affecting banana production worldwide, leading to yield losses of up to 65%. Consequently, numerous efforts to understand and mitigate drought effects that include developing tolerant crop varieties are ongoing in several banana breeding programmes. The breeding efforts, however, have been greatly slowed down by in...

The success of a breeding programme can be determined by the level of genetic diversity that exists among breeding materials. This study was carried out to (i) determine the level of genetic diversity that exist among the collection of tropical provitamin A maize inbred lines and (ii) evaluate the genetic structure and divergence of provitamin A ma...

The genetic architecture of seed protein content (SPC) and its relationships to agronomic traits in pigeonpea is poorly understood. Accordingly, five F2 populations segregating for SPC and four agronomic traits (seed weight (SW), seed yield (SY), growth habit (GH) and days to first flowering (DFF)) were phenotyped and genotyped using genotyping-by-...

Knowledge on the diversity and domestication levels of the spider plant (Gynandropsis gynandra) has the potential to affect pre-breeding for client-preferred traits, yet information is scarce in Namibia due to limited research. We investigated indigenous knowledge on the species diversity and domestication levels in the regions of Kavango West, Oha...

Yield is a complex quantitative trait largely influenced by the environment. Direct selection for grain yield is less efficient in improving groundnut productivity. The selection efficiency can be enhanced by exploiting the relationship between yield and its related traits. Moreover, the use of genetically diverse parents is essential to generate g...

Breeding drought tolerance in groundnuts cultivars would reduce yield losses due to drought stress in rain-fed growing areas. The mode of gene action governing the inheritance of drought tolerance and secondary traits was investigated by mating 30 lines according to North Carolina design II scheme. The parents and resulting 75 F2 progenies were gro...

Providing the growing population with quality diet under the changing climate requires renewed efforts on the breeding of orphan grain legumes that need to be adequately characterized for accelerated cultivar development, particularly in sub-Saharan Africa where food and nutritional insecurity remains a critical challenge. In this study, the phenot...

Provitamin A maize (Zea mays L.) biofortification is an ideal complementary means of combating vitamin A deficiency (VAD) in sub-Saharan Africa where maize consumption is high coupled by high VAD incidences. However, drought remains a major abiotic constraint to maize productivity in this region. Comprehensive drought screening of initial breeding...

The common bean (Phaseolus vulgaris L.) is among the most important grain legume crops in Africa. However, the common bean grain is heavily damaged by the Mexican bean weevil (Zabrotes subfasciatus Boheman). This study was conducted to determine the population structure and genome-wide marker–trait associations of bruchid resistance in the common b...

Designed crosses using genetically diverse and complementary genotypes is useful to develop sweetpotato clones with improved agronomic traits. The objective of this study was to determine combining ability and heterosis among selected sweetpotato clones for number of storage roots per plant (NRPP), storage root yield (SRY), dry matter content (DMC)...

Genotype-by-environment interaction analysis is key for selection and cultivar release, and to identify suitable production and test environments. The objective of this study was to determine the magnitude of genotype-by-environment interaction (GEI) for storage root yield, yield-related traits and sweet potato virus disease (SPVD) resistance among...

A participatory rural appraisal was conducted in selected groundnut growing areas of Uganda to determine how smallholder farmers perceive and cope with drought, identify farmers' constraints, and study the production systems, and varietal preferences in groundnut production. Majority of farmers surveyed, agreed that drought is a major production co...

Maize (Zea mays L.) has a great potential of combating food insecurity in sub-Saharan Africa because of its wide production and consumption in this region. However, its role in curbing nutrition insecurity is limited due to lack of key micronutrients such as vitamin A. This negates its capacity to be a suitable solution for both food and nutrition...