Research Article
Groundnut Host Plant and Vector Aphid (Aphis craccivora) Interaction in the Transmission of Groundnut Rosette Disease as a Basis for Physiological Studies
Issue:
Volume 13, Issue 1, February 2025
Pages:
1-8
Received:
19 January 2025
Accepted:
5 February 2025
Published:
20 February 2025
Abstract: Groundnut (Arachis hypogaea L.) is an important food crop in sub-Saharan Africa. Among the major causes for low yields is the susceptibility of cultivated varieties to the Groundnut Rosette Disease (GRD). The Groundnut Rosette is a viral disease, the most destructive where groundnut is grown, that can lead to 100% yield loss. The objectives of the study were to; 1) investigate the effect of leaf colour and plant architecture on aphid colonization; 2) determine the relationship between aphid colonization and disease development. An experiment was carried out in the glasshouse during winter of the 2018/19 and 2019/2020 growing seasons. Sixteen (16) test genotypes with known field reaction to the groundnut rosette disease were used. The results for disease severity concur with field ratings as all genotypes rated resistant had severity score of <1.39 and all genotypes rated moderate resistant, had scores <1 while susceptible genotypes recorded scores > 2.8. All susceptible genotypes had high aphid population (40 aphids on average per plant) whereby CG 7 had the highest. The results clearly show that, genotypes with dark green colour attracted more aphids (52.6) than the light green. Plant architecture may play a role in the migration of aphids within plants but does not influence plant preference by aphids. Genotypes ICGV-SM 01514, ICGV-SM 06637 and ICGV-SM 07544 attracted minimal number of aphids and were resistant to the rosette disease, a similar behaviour to ICG 12991, that is known to be aphid resistant. It can be concluded that these 3 genotypes are resistant to aphids. Genotypes ICGV-SM 01709, ICGV-SM 03710, ICGV-SM 08503 and ICGV-SM 01731 had considerable infestation by aphids (>40) but did not show any signs of the rosette disease, a trait that is common with ICGV-SM 90704, a variety resistant to grounndut rosette virus (GRV strain), an implication that they are resistant to the virus. The valuable results about these genotypes forms a basis for further characterization of these genotypes using molecular markers to understand the physiological basis of the varied reaction to vector and disease incidence. Sequencing the genome of the aphid species on groundnut is crucial to inform the diversity of the vector and give insights on how microbial effector proteins, host targets and plant immune receptors co-evolve.
Abstract: Groundnut (Arachis hypogaea L.) is an important food crop in sub-Saharan Africa. Among the major causes for low yields is the susceptibility of cultivated varieties to the Groundnut Rosette Disease (GRD). The Groundnut Rosette is a viral disease, the most destructive where groundnut is grown, that can lead to 100% yield loss. The objectives of the ...
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Research Article
Footprints of Edge Communities’ Exploitation of a Plant Species (Guiboutia Copallifera) Within Its Distributional Range in Sierra Leone
Issue:
Volume 13, Issue 1, February 2025
Pages:
9-20
Received:
12 January 2025
Accepted:
2 February 2025
Published:
11 March 2025
DOI:
10.11648/j.jps.20251301.12
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Abstract: This study investigates the impact of human activity on the diversity, abundance, and species composition of trees in southwestern Sierra Leone's Kasewe Forest Reserve. The specific objectives are to assess the historical use of Guibourtia copallifera in relation to the reserve and examine community relations with this species. Primary data were collected through a floristic inventory and key informant interviews, focusing on the use of forest land and floral resources. A total of 1,294 living specimens from 74 tree species and 12 lianas, belonging to 61 genera in 27 families, were recorded in the study. The most dominant species were Guibourtia copallifera, followed by Nesogordonia papaverifera, Memecylon normandii, and Gmelina arborea. Other species recorded at lower levels include Homalium africanum, Lindackeria dentata, Pentadesma butyracea, and Santiria trimera. Additionally, 675 stumps from 42 genera in 29 families were identified, with 88 trees showing harvesting marks. The study also recorded 147 old charcoal pits and 76 new charcoal pits. In the Kasewe Forest Reserve, 13 patches of Gmelina arborea plantations, along with 26 old and 11 new farms, were recorded. The study revealed that rapid anthropogenic activities and poor forest management have led to a decline in tree diversity. Edge communities remain crucial for the reserve's health, management, and future. Traditions, culture, and customs play a key role in the reserve's services and products, but the full historical use of the area is poorly documented. These findings highlight the urgent need for effective forest development and a recovery plan for degraded areas.
Abstract: This study investigates the impact of human activity on the diversity, abundance, and species composition of trees in southwestern Sierra Leone's Kasewe Forest Reserve. The specific objectives are to assess the historical use of Guibourtia copallifera in relation to the reserve and examine community relations with this species. Primary data were co...
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,
Njoroge Samuel
