Genetic diversity among accessions of Solanum aethiopicum L. groups based on morpho-agronomic traits

Abstract

Solanum aethiopicum L. is indigenous to Africa and constitutes an important vegetable. Morpho-agronomic traits were used to study diversity among 44 accessions of S. aethiopicum groups to identify traits of high discriminatory ability and donor parents with specific or multiple traits for introgression and utilization in breeding programmes. Field experiments were conducted from 2008 to 2010. The principal component (PC) analysis of morpho-agronomic data indicated high discriminatory ability for fruit calyx length, fruit length and leaf length. On PC1, fruit length showed positive and significant correlation coefficients with leaf length, fruit calyx length and width. An independent association was recorded among fruit width, fruits per infructescence and seed yield (t/ha). Ordination (biplot) and grouping (dendrogram) revealed genetic variation and relatedness, phenotypic plasticity and geographical heterogeneity among the accessions within and among the clusters. Members of cluster 1 (group ‘c’) are a promising donor parent for multiple traits (earliness and fruit length), and members of group ‘b’ are superior for fruits per plant, fruits per infructescence and fruit infructescence per plant. Hybridization among distant clusters would provide an opportunity for bringing together gene constellations of diverse background. Earliness and fruit length were highly variable among the S. aethiopicum groups. The results are important for the breeding and selection of this crop.

Linear discriminant analysis of structure within African eggplant ‘Shum’

“…The results on hierarchical clustering indicated existence of strong population structures within the S. aethiopicum 'Shum' group, contrary to observations made by Adeniji et al (2012Adeniji et al ( , 2013 and Plazas et al (2014). However, it is notable that the duo did not assess the structure based on Mantel test, which gives a cophenetic correlation coefficient (CPCC), and they compared all the four recognised morphotypes of S. aethiopicum (Shum, Gilo, Kumba and Aculeatum) in 'one' analysis (Adeniji et al, 2012(Adeniji et al, , 2013Plazas et al, 2014;Gramazio et al, 2016). The CPCC is one of the reliable measures of genetic diversity applicable to both molecular and morpho-agronomic data variables (Murtagh, 2017;Nikoliae et al, 2017).…”

“…The observation suggests that other than leaf area, reproductive traits are putatively good morphological markers in S. aethiopicum 'Shum' group. Similar views were made by Adeniji et al (2012) and Plazas et al (2014) when they studied world collections of S. aethiopicum groups namely Shum, Gilo, Kumba and Aculeatum for genetic diversity based on morphological attributes.…”

“…A completely randomised design was used in which 24 plants (12 for data collection at seedling/vegetative stages, and remaining 12 for reproductive/fruiting stage) per accession were evaluated. Each pot was Table 2, and most of these traits have been described earlier by Plazas et al (2014), Adeniji et al (2012Adeniji et al ( , 2013 and Kubie (2013 y ij is the observed trait measurement for a group of accessions in the i th cluster (C) and j th experiment (R); µ and ε ij refer to overall cluster mean for a trait and random error, respectively.…”

“…Conspicuously, the Shum were notably insufficiently represented when compared with the Gilo, for example (Adeniji et al, 2012;Plazas et al, 2014). The lumping up and limited representation for the Shum could have masked the exposure of within-group structure (Plazas et al, 2014).…”

Diversity and distribution of African indigenous vegetable species in Uganda

“…The traditional African vegetables have thus been documented for multiple uses such as food, cash, medicinal, cultural and ornamental purposes (AbukutsaOnyango, 2014;Ebert, 2014;Omulo, 2016). Other types of AIVS exist based on plant part used; mainly leafy, fruit, seed and root vegetables (Adeniji et al, 2012;BationoKando et al, 2015;Borràs et al, 2015;Kouassi et al, 2014;Prohens et al, 2013). The most important AIVS in Uganda are consumed as leaves for instance Solanum aethiopicum 'Shum group', Amaranthus spp., Abelmoschus esculentus and Hibiscus sabdarifa (Omulo, 2016;Pincus, 2015).…”