Groundnuts

Permanent URI for this collectionhttp://104.225.218.216/handle/123456789/14

Disease and Pest resistance, Drought Tolerance, Tolerance to low fertility soils, Yield improvement, Pre- and post-harvest management, upland and low land varieties, Nutrition enhancement.

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Now showing 1 - 7 of 7

Exploration of Alternative Approaches to Phenotyping of Late Leaf Spot and Groundnut Rosette Virus Disease for Groundnut Breeding
(Frontiers in Plant Science, 2022-06-14) Ivan Chapu; David Kalule Okello; Robert C. Ongom Okello; Thomas Lapaka Odong; Sayantan Sarka; Maria Balota
Late leaf spot (LLS), caused by Nothopassalora personata (Berk. & M.A Curt.), and groundnut rosette disease (GRD), [caused by groundnut rosette virus (GRV)], represent the most important biotic constraints to groundnut production in Uganda. Application of visual scores in selection for disease resistance presents a challenge especially when breeding experiments are large because it is resource-intensive, subjective, and error- prone. High-throughput phenotyping (HTP) can alleviate these constraints. The objective of this study is to determine if HTP derived indices can replace visual scores in a groundnut breeding program in Uganda. Fifty genotypes were planted under rain-fed conditions at two locations, Nakabango (GRD hotspot) and NaSARRI (LLS hotspot). Three handheld sensors (RGB camera, GreenSeeker, and Thermal camera) were used to collect HTP data on the dates visual scores were taken. Pearson correlation was made between the indices and visual scores, and logistic models for predicting visual scores were developed. Normalized difference vegetation index (NDVI) (r = –0.89) and red-green-blue (RGB) color space indices CSI (r = 0.76), v∗ (r = –0.80), and b∗ (r = –0.75) were highly correlated with LLS visual scores. NDVI (r = –0.72), v∗ (r = –0.71), b∗ (r = –0.64), and GA (r = –0.67) were best related to the GRD visual symptoms. Heritability estimates indicated NDVI, green area (GA), greener area (GGA), a∗, and hue angle having the highest heritability (H2 > 0.75). Logistic models developed using these indices were 68% accurate for LLS and 45% accurate for GRD. The accuracy of the models improved to 91 and 84% when the nearest score method was used for LLS and GRD, respectively. Results presented in this study indicated that use of handheld remote sensing tools can improve screening for GRD and LLS resistance, and the best associated indices can be used for indirect selection for resistance and improve genetic gain in groundnut breeding.
Quantitative Trait Analysis Shows the Potential for Alleles from the Wild Species Arachis batizocoi and A. duranensis to Improve Groundnut Disease Resistance and Yield in East Africa
(Agronomy, 2022-09-16) Danielle A. Essandoh; Thomas Odong; David K. Okello; Daniel Fonceka; Joël Nguepjop; Aissatou Sambou; Carolina Ballén-Taborda; Carolina Chavarro; David J. Bertioli; Soraya C. M. Leal-Bertioli
Diseases are the most important factors reducing groundnut yields worldwide. In East Africa, late leaf spot (LLS) and groundnut rosette disease (GRD) are the most destructive diseases of groundnut. Limited resistance is available in pure pedigree cultivated groundnut lines and novel sources of resistance are required to produce resistant new varieties. In this work, 376 interspecific lines from 3 different populations derived from crosses with the wild species A. duranensis, A. ipaënsis, A. batizocoi and A. valida were phenotyped for 2 seasons and across 2 locations, Serere and Nakabango, in Uganda. Several genotypes showed a higher yield, a larger seed, an earlier flowering, and similar resistance to the local cultivar checks. Genotypic data was used to construct a linkage map for the AB-QTL population involving the cross between Fleur11 and [A. batizocoi x A. duranensis]4x. This linkage map, together with the phenotypic data was used to identify quantitative trait loci controlling disease resistance. These lines will be useful in combining good agronomic traits and stacking disease resistance to improve the groundnut crop in sub-Saharan Africa.
Registration of ‘Naronut 1R’ groundnut
(Journal of Plant Registrations, 2022-10-26) David K. Okello; C. Michael Deom; Naveen Puppala
‘Naronut 1R’ (Reg. no. CV-150, PI 693985) is a high-yielding, Spanish-type ground- nut (Arachis hypogaea L. subsp. fastigiata var. vulgaris) cultivar with a red seed coat and two seeds per pod. The cultivar was selected from a cross between International Crops Research Institute for the Semi-arid Tropics advanced lines ‘ICGV-SM 90704’ and ‘ICGV-SM 86715’. Naronut 1R was developed for groundnut rosette disease resistance, late leafspot resistance, yield, red seed coat, and early maturity. Naronut 1R matures in 75–80 d after planting, compared with 90 d for the widely grown and popular landrace Erudu red (Spanish-type groundnut). Naronut 1R has much higher yields (1,473 kg ha−1) than Erudu red (554 kg ha−1). The overall groundnut rosette disease rating was 44% lower in Naronut 1R (2.8 disease rating) compared with Erudu red (5.0 disease rating). Similarly, the overall late leafspot disease rat- ing was 28% lower in Naronut 1R (3.6 disease rating) compared with Erudu red (5.0 disease rating). Similar to Erudu red, Naronut 1R seed testa is red, but the seed is larger. The sound mature kernel weight was 9.42% higher for Naronut 1R than for Erudu red. The shelling percentage for Naronut 1 was 49.3%, whereas Erudu red was 60%. Naronut 1R has lower protein (18.1 vs. 21.3%) and oil content (36.0 vs. 44.3%) than Erudu red. Naronut 1R will allow for broad adoption of a high yielding, early maturing, red seed coat cultivar that carries resistance to groundnut rosette disease and late leaf spot disease.
Multi-locus genome-wide association studies reveal genomic regions and putative candidate genes associated with leaf spot diseases in African groundnut (Arachis hypogaea L.) germplasm
(2023-01-05) Richard Oteng-Frimpong; Benjamin Karikari; Emmanuel Kofi Sie; Yussif Baba Kassim; Doris Kanvenaa Puozaa; Masawudu Abdul Rasheed; Daniel Fonceka; David Kallule Okello; Maria Balota; Mark Burow; Peggy Ozias-Akins
Early leaf spot (ELS) and late leaf spot (LLS) diseases are the two most destructive groundnut diseases in Ghana resulting in ≤ 70% yield losses which is controlled largely by chemical method. To develop leaf spot resistant varieties, the present study was undertaken to identify single nucleotide polymorphism (SNP) markers and putative candidate genes underlying both ELS and LLS. In this study, six multi-locus models of genome-wide association study were conducted with the best linear unbiased predictor obtained from 294 African groundnut germplasm screened for ELS and LLS as well as image-based indices of leaf spot diseases severity in 2020 and 2021 and 8,772 high-quality SNPs from a 48 K SNP array Axiom platform. Ninety-seven SNPs associated with ELS, LLS and five image-based indices across the chromosomes in the 2 two sub-genomes. From these, twenty-nine unique SNPs were detected by at least two models for one or more traits across 16 chromosomes with explained phenotypic variation ranging from 0.01 - 62.76%, with exception of chromosome (Chr) 08 (Chr08), Chr10, Chr11, and Chr19. Seventeen potential candidate genes were predicted at ± 300 kbp of the stable/prominent SNP positions (12 and 5, down- and upstream, respectively). The results from this study provide a basis for understanding the genetic architecture of ELS and LLS diseases in African groundnut germplasm, and the associated SNPs and predicted candidate genes would be valuable for breeding leaf spot diseases resistant varieties upon further validation.
Genome‐wide association studies reveal novel loci for resistance to groundnut rosette disease in the African core groundnut collection
(Theoretical and Applied Genetics, 2023-03-10) Esther Achola; Peter Wasswa; Daniel Fonceka; Josh Paul Clevenger; Prasad Bajaj; Peggy Ozias‐Akins; Jean‐François Rami; Carl Michael Deom; David A. Hoisington; Richard Edema; Damaris Achieng Odeny; David Kalule Okello
Key message We identified markers associated with GRD resistance after screening an Africa-wide core collection across three seasons in Uganda Abstract Groundnut is cultivated in several African countries where it is a major source of food, feed and income. One of the major constraints to groundnut production in Africa is groundnut rosette disease (GRD), which is caused by a complex of three agents: groundnut rosette assistor luteovirus, groundnut rosette umbravirus and its satellite RNA. Despite several years of breeding for GRD resistance, the genetics of the disease is not fully understood. The objective of the current study was to use the African core collection to establish the level of genetic variation in their response to GRD, and to map genomic regions responsible for the observed resistance. The African groundnut core genotypes were screened across two GRD hotspot locations in Uganda (Nakabango and Serere) for 3 seasons. The Area Under Disease Progress Curve combined with 7523 high quality SNPs were analyzed to establish marker-trait associations (MTAs). Genome-Wide Association Studies based on Enriched Compressed Mixed Linear Model detected 32 MTAs at Nakabango: 21 on chromosome A04, 10 on B04 and 1 on B08. Two of the significant markers were localised on the exons of a putative TIR-NBS-LRR disease resistance gene on chromosome A04. Our results suggest the likely involvement of major genes in the resistance to GRD but will need to be further validated with more comprehensive phenotypic and genotypic datasets. The markers identified in the current study will be developed into routine assays and validated for future genomics-assisted selection for GRD resistance in groundnut.
Effect of Phosphorus-Based Fertilizer on Groundnut Yield and Incidence of Groundnut Rosette Disease in West Nile Region of Uganda
(National Agricultural Research Organisation, 2023-09-01) Alex Abaca; Emmanuel Odama; Alfred Komakech; Sadik Kassim; John K. Walakira
The objective of this study was to establish the effects of Di-ammonium phosphate (DAP) fertilizer micro-dosing on yields and the incidence of groundnut rosette disease (GRD) on five groundnut varieties in West Nile region of Uganda. The field experimental design used in this study was 5x2 factorial laid in a randomized complete block design (RCBD) with three replicates per location across 6 locations. The results indicated that there were significant (p = 0.05) differences in groundnuts yields across locations and varieties (0.554 – 1.742 tons per hectare) with or without micro-dosing with DAP fertilizer. The effects of DAP fertilizer micro-dosing in groundnut production were twofold: increase in yields across locations from 427.27kg/acre with no micro-dosing to 525.73kg/acre with micro-dosing (23.04% increment) and varieties from 420.46kg/acre with no micro-dosing to 529.71kg/acre with micro-dosing (13.77% increment); and a reduction of groundnut rosette virus disease incidence across locations from 15.13% with no micro-dosing to 11.20 with micro-dosing (27.76% reduction) and on varieties from 15.08% with no micro-dosing to 11.82% with micro-dosing (34.62% reduction). This is the first report of a prospective DAP fertilizer micro-dosing alongside other improved agronomic practices which can be integrated fully into groundnut production in West Nile region of Uganda. To manage yields and GRD incidences, micro-dosing of crops should be taken as a climate smart technology as identified by Food and Agricultural Organization.
Assessing Herbicide Use and Hand Weeding Efficacy in Groundnut Production Intensification
(Journal of Agricultural Science, 2025-03-15) Paul Anguria; Essegbemon Akpo; Chris O. Ojiewo; Michael A. Ugen
Poor and costly weed management constrains Groundnut (Arachis hypogea L.) production in Uganda. A field study was therefore conducted at the National Semi-Arid Resources Research Institute (NaSARRI), Serere, Uganda during the long rains of 2020 and 2021 and short rains of 2020 to evaluate the efficacy of hand weeding and different herbicides on weed management, yield, and the economics of their use in groundnut. The experiment for this study comprised 7 treatments constituted by six herbicides; four pre-emergent (Glyphosate, Clethodim, S-Metolachlar, and 2,4-Dichlorophenoxyacetic acid), and two post-emergent (Bentazone and Quizalofop-p-ethyl) and hand weeding. Post-emergence herbicide application and hand weeding were done at 30, 45, and 60 DAS. The treatments were laid out in a randomized complete block design (RCBD) with three replications. Calculated weed indices show the effect of weed control measures on groundnut weeds. Pre-emergence application of glyphosate followed by post-emergence application of Quizalofop-p-ethyl produced superior pod yield (1724.3 kg/ha), the lowest weed density of grass (0.62), and Sedges (0.61), the lowest weed biomass at harvest (122.5g), the highest percentage of weed control efficiency (69.65%), and highest net returns (7,937,746UGX/ha). However, post-emergence sole application of quizalofop-p-ethyl produced the highest B: C ratio (36.49). Therefore, this study has indicated that the pre-emergence application of glyphosate followed by the post-emergence application of quizalofop-p-ethyl is the most profitable weed control measure in groundnut; while the post-emergence sole application of quizalofop-p-ethyl is the most economical. Hand weeding though may be used where labour is cheap and not scarce as opposed to the herbicides.

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