Kwadwo Ofori

Diversity in 113 cowpea (Vigna unguiculata (L) Walp) accessions assessed with 458 SNP markers

Single Nucleotide Polymorphism (SNP) markers were used in characterization of 113 cowpea accessions comprising of 108 from Ghana and 5 from abroad. Leaf tissues from plants cultivated at the University of Ghana were genotyped at KBioscience in the United Kingdom. Data was generated for 477 SNPs, out of which 458 revealed polymorphism. The results were used to analyze genetic dissimilarity among the accessions using Darwin 5 software. The markers discriminated among all of the cowpea accessions and the dissimilarity values which ranged from 0.006 to 0.63 were used for factorial plot. Unexpected high levels of heterozygosity were observed on some of the accessions. Accessions known to be closely related clustered together in a dendrogram drawn with WPGMA method. A maximum length sub-tree which comprised of 48 core accessions was constructed. The software package structure was used to separate accessions into three groups, and the programme correctly identified varieties that were known hybrids. The hybrids were those accessions with numerous heterozygous loci. The structure plot showed closely related accessions with similar genome patterns. The SNP markers were more efficient in discriminating among the cowpea germplasm than morphological, seed protein polymorphism and simple sequence repeat studies reported earlier on the same collection.

GENETIC CONTROL OF SEED SIZE IN COWPEA (Vigna unguiculata (L.) Walp)

Seed size contributes to yield and it is also a consumer trait of cowpea in Ghana and other parts of the world. Ghanaian consumers tend to prefer large seeded cowpea to small sizes although, Ghanaian varieties have smaller seeds compared to the imported types. This might be a contributing factor to high importation of cowpea to Ghana. To breed cowpeas with large grains, it is paramount to understand the inheritance of the trait. Generation mean analysis was performed to estimate gene actions on seed size of cowpea using CB27 and Gh3710 as the large and small seeded parents respectively. It was observed that eight genes control seed size and that small seed is partially domi- nant over large seed. The estimated broad sense heritability was 84% while the narrow sense was 35%. Both additive and non-additive genes with their interactions in the exception of additive - additive had significant effect on seed size inheritance in cowpea. The inheritance of seed size was observed to be complex, it was suggested that combinations of methods such as single seed descent and backcross methods with selection from early generations through advanced level would help improve seed size of cowpea.

Breeding Superior Orange-Fleshed Sweetpotato Cultivars for West Africa

ABSTRACT Vitamin A deficiency (VAD) is of public health significance in the developing world. In spite of extensive promotion of orange-fleshed sweetpotato (Ipomoea batatas) varieties (OFSPs), they are poorly utilized in Ghana because of their low dry matter and high sugar content. The objective of this study was to develop farmer- and consumer-preferred beta-carotene-rich varieties to increase OFSP utilization in Ghana and beyond. One released variety in Ghana (Apomuden) and four other varieties which are introductions (Beauregard, Resisto, CIP 442850, and CIP 443035) were used as parents. They were crossed using the full diallel mating design. There was significant genetic variation for the traits and among the F1 hybrids. Significant positive and negative heterosis was found, but the levels were not adequate for the development of non-sweet, high dry matter, and high beta-carotene-rich varieties. Twenty-one F1 hybrids that had comparable beta-carotene content and storage root yield but lower sugar content than the only released high-beta-carotene variety in Ghana were identified for further testing for potential release.

Perceptions of Rain-Fed Lowland Rice Farmers on Climate Change, Their Vulnerability, and Adaptation Strategies in the Volta Region of Ghana

Climate change is already impacting negatively on Africa through extreme temperatures, frequent flooding and droughts, and increased salinity of water supplies used for irrigation (IPCC 2007). Widespread poverty and high dependence on rain-fed agriculture in Africa renders the continent more vulnerable to climate change–induced disasters than other regions of the world. Sub-Saharan African countries form the bulk of countries in a protracted food crisis (FAO 2010). The recent waves of food crisis in West Africa attest to this (Oxfam 2010). Therefore, urgent measures need to be undertaken to improve the resilience of African communities, especially those in rural areas, to enable them to better adapt to climate change and other constraints to food production. In the next decades, world food demand is projected to increase as it is currently being rapidly redefined by new driving forces (von Braun 2007). Income growth, climate change, high energy prices, globalization, and urbanization are transforming food production, consumption, and markets. Economic growth (especially in some Asian countries) has helped to reduce hunger through increased propensity to consume (von Braun 2007); the prices and markets of the world are getting increasingly linked and have significant effects in food consumption patterns (Sardaryan 2002). There is a current dilemma on diverting farmland meant for food crops to growing crops for biofuel as a measure to mitigate climate change.

Genetic Variability and Its Implications on Early Generation Sorghum Lines Selection for Yield, Yield Contributing Traits, and Resistance to Sorghum Midge

Sorghum is the second most important cereal crop in Niger. The crop is grown in a wide range of ecological environments in the country. However, sorghum grain yield in Niger is limited by both abiotic and biotic constraints. Recombinant inbred lines derived from the cross of a local variety with a midge resistant variety and two local checks were evaluated during the 2015 rainy season across two planting dates in two environments in Niger. The objective was to investigate genetic variability for yield, yield related traits, and resistance to sorghum midge. High phenotypic coefficient of variation (PCV) versus genotypic coefficient of variation (GCV) was observed in both sites and planting dates. Across planting dates at both Konni and Maradi, grain yield, plant height, panicle weight, and midge damage had high heritability coupled with high estimates of genetic advance. At Konni, high genetic advance coupled with high heritability was detected for grain yield, plant height, panicle weight, and resistance to midge. There were similar results at Maradi for grain yield, plant height, and panicle weight. Therefore, selection might be successful for the above characters in their respective environments.

Genetic control of dry matter, starch and sugar content in sweetpotato

ABSTRACT Sweetpotato (Ipomoea batatas L. (Lam)) is a nutritious food security crop for most tropical households, but its utilisation is very low in Ghana compared to the other root and tuber crops due to lack of end-user-preferred cultivars. Knowledge on the genetic control of important traits such as dry matter, starch and sugar content of sweetpotato storage roots in a breeding population is critical for making breeding progress in developing sweetpotato varieties preferred by farmers and consumers. This study used diallel mating design to elucidate general combining ability and specific combining ability, to determine the gene action controlling storage root dry matter, starch and sugar content in sweetpotato and the heterotic potential of the traits to facilitate the crop’s improvement for increased utilisation. A general model for estimating genetic effects, GEAN II, was used to analyse the data. Genetic variability was seen for dry matter, starch and sugar content of sweetpotato and much of this genetic variation was additive in nature. The study also revealed significant heterosis in sweetpotato which offers opportunity for breeding non-sweet, high dry matter sweetpotato varieties that are preferred by farmers and consumers in Ghana.

Agronomic performance of early segregating generations of rice under salt stress in Niger

Salinity is a major abiotic constraint that retrains rice production worldwide. The development and release of rice cultivars with improved performance in saline environments is essential to fight against this scourge. Hence this study was carried out to evaluate segregating populations of rice in Niger where salinity is a major constraint. Thus 120 F3 families derived from a diallel cross of four parents were evaluated in salt-affected farmers fields at two sites. The experimental design was an alpha lattice 25*5 with three replications and two sites. Data on the cycle, height, tiller number, panicle number, panicle weight, grain weight, and yield were recorded. Data were analysed using SAS 9.2 and least significant difference was used for means separation. Yield potential under salt stress varied significantly among F3 families ranging from 2.52 to 4.17 t ha−1. Correlation analysis among traits showed that yield was significantly and positively associated with height, tiller and panicle number, and panicle weight. The 20 best-performing families with a high selection index were selected for advancement for farmers adoption.

Farmer participation in selection within segregating populations of cowpea in Volta Region, Ghana

BackgroundParticipatory plant breeding leads to early adoption of a newly released variety as farmers would be aware of whatever advantage it might have over prior existing ones as early as possible. Cowpea farmers around Ohawu in the Volta Region of Ghana where the crop is one of the most important cash crops had no variety specifically developed for their environment. This research followed farmers’ interest identified earlier for the development of varieties with preferred consumer traits.MethodsFarmers were chosen from 25 communities within the cowpea growing area by the help of agricultural extension officers. Fifty farmers including 25 males and females each, 7 scientists and 15 other persons with different backgrounds were involved in the selection exercise. The final plants selected were based on the total number of participants’ endorsement and analysis of variance for their seed size.ResultsSelections were made from six F3 populations with parents of various unique traits obtained from Botswana, Ghana, Nigeria, Senegal, or United States of America. Four most liked cowpea plants from each of the six populations were selected to be advanced and tried in multi-locations towards probable release.ConclusionsParticipants were very enthused with the selection exercise hoping of seeing some of their selections resulting into varieties. Farmers were interested in selecting plants with long multiple pods and early maturing. The exercise was educative for all participants.