Variation in Seedling Germination and Growth in Five Populations Of vitellariaparadoxa C.F. Gaertn.subsp. Nilotica: A Threatened useful fruit Tree Species in Uganda
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Date
2020
Journal Title
Journal ISSN
Volume Title
Publisher
Research Square
Abstract
We studied seedlings germination and growth performance in an economically and socially
important fruit tree species of Vitellaria paradoxaC.F. Gaertn.subsp. nilotica (Kotschy) in Uganda. The
study aimed at determining variability in germination of the five shea tree seed lots and seedlings growth
performance based on their growth traits. Five populations were considered from four agroecological
zones of Uganda and 180 candidates plus trees (16 ethnovarieties) selected as seed trees based on their
traits for faster growth and high oil yield. A total of 1204 biological seeds were collected and sown in a
general tree nursery at Ngetta Zonal Agricultural Research and Development Institute (NgeZARDI)during
the month of June 2018 in a randomized incomplete block design with three replications.
Results: Significant variation (χ = 526; p < 0.01) was observed in seedling phenotypic traits within and
between populations. Regression equation for height growth and leaf size index were given asy = 0.3787
+ 12.671x and y = 0.6483 + 15.413x respectively. Root collar diameter was more correlated to leaf size
index (0.425) than to height growth (0.30). Clustering of shea tree seedlings based on phenotypic growth
traits revealed one aggregated cluster indicating that most of the seedlings from the five populations
were similar (Jaccard index 0.92, p < 0.01). However, clustering based on SNP markers revealed three
different populations. We recorded higher growth (χ = 708; p< 0.001) in Arua shea population (19.69
cm)compared to the population average (19.04 cm). Red seeded; thin pulped and hairy fruited shea tree
ethnovarieties assumed faster growth than the rest.
Conclusions: The phenotypic analysis of shea tree seedlings revealed some fast-growing genotypes from
the five studied populations. Thesegenotypes can be selected for faster growth for shea tree breeding in
Uganda.
Description
Keywords
Ethnovariety, Plantlets, Root collar diameter, Leaf size index, Population, Cluster
Citation
Odoi, J. B., Odong, T. L., Okia, C. A., Okullo, J. L., Okao, M., Kabasindi, H., ... & Gwali, S. (2020). Variation in Seedling Germinationand Growth in Five Populations Ofvitellariaparadoxa CF Gaertn. subsp. Nilotica: A Threatened useful fruit Tree Species in Uganda. https://doi.org/10.21203/rs.3.rs-35471/v1