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Detailed knowledge on genetic diversity among germplasm is important for hybrid maize (Zea mays L.) breeding. The objective of the study was to determine genetic diversity in widely grown hybrids in Southern Africa, and compare effectiveness of phenotypic analysis models for determining genetic distances between hybrids. Fifty hybrids were evaluated at one site with two replicates. The experiment was a randomized complete block design. Phenotypic and genotypic data were analyzed using SAS and Power Marker respectively. There was significant (p < 0.01) variation and diversity among hybrid brands but small within brand clusters. Polymorphic Information Content (PIC) ranged from 0.07 to 0.38 with an average of 0.34 and genetic distance ranged from 0.08 to 0.50 with an average of 0.43. SAH23 and SAH21 (0.48) and SAH33 and SAH3 (0.47) were the most distantly related hybrids. Both single nucleotide polymorphism (SNP) markers and phenotypic data models were effective for discriminating genotypes according to genetic distance. SNP markers revealed nine clusters of hybrids. The 12-trait phenotypic analysis model, revealed eight clusters at 85%, while the five-trait model revealed six clusters. Path analysis revealed significant direct and indirect effects of secondary traits on yield. Plant height and ear height were negatively correlated with grain yield meaning shorter hybrids gave high yield. Ear weight, days to anthesis, and number of ears had highest positive direct effects on yield. These traits can provide good selection index for high yielding maize hybrids. Results confirmed that diversity of hybrids is small within brands and also confirm that phenotypic trait models are effective for discriminating hybrids.

The effect of peeling and boiling process was investigated on nutrients and health-promoting compounds of amadumbe (Colocasia esculenta), carrots (Daucus carota), sweet potatoes (Ipomoea batatas) and potatoes (Solanum tuberosum). The results indicated that peeling and boiling led to significant reduction of nutrients (total soluble starch, total soluble protein, crude fibre) and health-promoting compounds (flavonols, anthocyanin and phenolic acid). Peeling effects on nutrient content did not yield similar outcome (increase and decrease). Carrots showed insignificant loss of total soluble starch after peeling and major loss was observed after boiling. Amadumbe shows substantial loss of fibre after peeling, peels yielding 42.38% and edible part yielding 8.31% compared to all of the analysed vegetables. Health-promoting compounds were reduced significantly peeling and boiling process. The nutrient and phytochemical compounds in the peels of the various vegetables depends on method of peeling. Fourier-Transform Infrared Spectroscopy (FT-IR) bands evidenced the presence of nutrients and health-promoting compounds in studied vegetables. Keywords: Boiling; Flavonols; Health promoting compounds; Nutrients; Peeling; Phenolic acid