Characterization and Morphological Diversity of Local Avocado Germplasm (Persea americana Mill.) from Northern Tanzania

Tanzania’s diverse agroecological zones offer ideal conditions for cultivating tropical fruits, including avocados, which are economically and nutritionally important. This study assessed the morphological diversity of seed-propagated avocado germplasm from Northern Tanzania’s Tanga, Kilimanjaro, an...

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Main Authors: Iman S. Yangaza, Charles O. Joseph, Emmanuel M. Sangu, Agnes M.S Nyomora
Format: Article
Language:English
Published: Taylor & Francis Group 2025-12-01
Series:International Journal of Fruit Science
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Online Access:https://www.tandfonline.com/doi/10.1080/15538362.2025.2513078
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author Iman S. Yangaza
Charles O. Joseph
Emmanuel M. Sangu
Agnes M.S Nyomora
author_facet Iman S. Yangaza
Charles O. Joseph
Emmanuel M. Sangu
Agnes M.S Nyomora
author_sort Iman S. Yangaza
collection DOAJ
description Tanzania’s diverse agroecological zones offer ideal conditions for cultivating tropical fruits, including avocados, which are economically and nutritionally important. This study assessed the morphological diversity of seed-propagated avocado germplasm from Northern Tanzania’s Tanga, Kilimanjaro, and Arusha regions. Two hundred seventy mature avocado trees were sampled from farmers in two districts per region. The samples were characterized using 14 descriptor variants from the International Plant Genetic Resources Institute (IPGRI) avocado descriptor list. Quantitative traits were analyzed through one-way Analysis of Variance (ANOVA) with populations (districts) and altitude ranges as factors. Qualitative characteristics were assessed using cross-tabulation, Chi-square, and Fisher’s exact tests. Linear Discriminant Analysis (LDA) and Hierarchical Cluster Analysis (HCA) explored morphological diversity relationships. The results revealed significant variation in quantitative traits (p < .05). Karatu and Meru had the highest number of primary leaf veins (18.84 ± 0.16), while Rombo had the lowest (15.13 ± 0.09). Karatu, Meru, Moshi and Rombo displayed the highest leaf vein divergence (42.33 ± 0.33), and Lushoto the lowest (37.78 ± 0.36). The study observed diverse morphological traits, predominantly of the Mexican and Guatemalan races, with some West Indian traits concentrated in Rombo. Novel morphological variants absent in the IPGRI guidebook were recorded. LDA suggested slight geographical clustering within regions, while Rombo trees formed distinct clusters. The dendrogram revealed admixture across populations, indicating gene flow through seed movement. This study confirms the value of morphological markers in detecting avocado diversity in varying agroecological conditions. It underscores the high morphological diversity of Northern Tanzania’s avocado germplasm, emphasizing its conservation and breeding potential.
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spelling doaj-art-25c42ae3e0d640b2911ded37f8a0c02e2025-08-20T03:06:51ZengTaylor & Francis GroupInternational Journal of Fruit Science1553-83621553-86212025-12-0125111910.1080/15538362.2025.2513078Characterization and Morphological Diversity of Local Avocado Germplasm (Persea americana Mill.) from Northern TanzaniaIman S. Yangaza0Charles O. Joseph1Emmanuel M. Sangu2Agnes M.S Nyomora3Department of Botany, University of Dar es Salaam, P.O Box 35060, Dar es Salaam, TanzaniaDepartment of Crop Science and Beekeeping Technology, University of Dar Es Salaam, P.O Box 35143, Dar Es Salaam, TanzaniaDepartment of Botany, University of Dar es Salaam, P.O Box 35060, Dar es Salaam, TanzaniaSt. Augustine University of Tanzania, P.O Box 307, Mwanza, TanzaniaTanzania’s diverse agroecological zones offer ideal conditions for cultivating tropical fruits, including avocados, which are economically and nutritionally important. This study assessed the morphological diversity of seed-propagated avocado germplasm from Northern Tanzania’s Tanga, Kilimanjaro, and Arusha regions. Two hundred seventy mature avocado trees were sampled from farmers in two districts per region. The samples were characterized using 14 descriptor variants from the International Plant Genetic Resources Institute (IPGRI) avocado descriptor list. Quantitative traits were analyzed through one-way Analysis of Variance (ANOVA) with populations (districts) and altitude ranges as factors. Qualitative characteristics were assessed using cross-tabulation, Chi-square, and Fisher’s exact tests. Linear Discriminant Analysis (LDA) and Hierarchical Cluster Analysis (HCA) explored morphological diversity relationships. The results revealed significant variation in quantitative traits (p < .05). Karatu and Meru had the highest number of primary leaf veins (18.84 ± 0.16), while Rombo had the lowest (15.13 ± 0.09). Karatu, Meru, Moshi and Rombo displayed the highest leaf vein divergence (42.33 ± 0.33), and Lushoto the lowest (37.78 ± 0.36). The study observed diverse morphological traits, predominantly of the Mexican and Guatemalan races, with some West Indian traits concentrated in Rombo. Novel morphological variants absent in the IPGRI guidebook were recorded. LDA suggested slight geographical clustering within regions, while Rombo trees formed distinct clusters. The dendrogram revealed admixture across populations, indicating gene flow through seed movement. This study confirms the value of morphological markers in detecting avocado diversity in varying agroecological conditions. It underscores the high morphological diversity of Northern Tanzania’s avocado germplasm, emphasizing its conservation and breeding potential.https://www.tandfonline.com/doi/10.1080/15538362.2025.2513078Avocado germplasmdendrogramgenetic diversitymorphological descriptorsprincipal component analysis
spellingShingle Iman S. Yangaza
Charles O. Joseph
Emmanuel M. Sangu
Agnes M.S Nyomora
Characterization and Morphological Diversity of Local Avocado Germplasm (Persea americana Mill.) from Northern Tanzania
International Journal of Fruit Science
Avocado germplasm
dendrogram
genetic diversity
morphological descriptors
principal component analysis
title Characterization and Morphological Diversity of Local Avocado Germplasm (Persea americana Mill.) from Northern Tanzania
title_full Characterization and Morphological Diversity of Local Avocado Germplasm (Persea americana Mill.) from Northern Tanzania
title_fullStr Characterization and Morphological Diversity of Local Avocado Germplasm (Persea americana Mill.) from Northern Tanzania
title_full_unstemmed Characterization and Morphological Diversity of Local Avocado Germplasm (Persea americana Mill.) from Northern Tanzania
title_short Characterization and Morphological Diversity of Local Avocado Germplasm (Persea americana Mill.) from Northern Tanzania
title_sort characterization and morphological diversity of local avocado germplasm persea americana mill from northern tanzania
topic Avocado germplasm
dendrogram
genetic diversity
morphological descriptors
principal component analysis
url https://www.tandfonline.com/doi/10.1080/15538362.2025.2513078
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AT emmanuelmsangu characterizationandmorphologicaldiversityoflocalavocadogermplasmperseaamericanamillfromnortherntanzania
AT agnesmsnyomora characterizationandmorphologicaldiversityoflocalavocadogermplasmperseaamericanamillfromnortherntanzania