Differences in Fruit Size, Postharvest Pathology and Phytochemicals between Irvingia gabonensis and Irvingia wombolu

Abstract

<p><em>Irvingia </em>(bush mango) species are economically important trees, but studies aimed at their prospect for domestication did not take into account the potential differences between members of the Genus. Hence fruit size, postharvest pathology and phytochemicals of <em>I. gabonensis </em>and <em>I. wombolu</em> were studied. Results showed that whilst the mean weight, length, width and thickness of fruits of <em>I. gabonensis </em>were 125.08g, 60.85mm, 62.66mm and 56.78mm, respectively, those obtained from <em>I. wombolu </em>were 86.08g, 54.23mm, 54.09mm and 50.97mm, respectively. Difference in brownish-black rot fruit disease between the two <em>Irvingia</em> species was not significant (<em>P=0.05</em>), but disease severity increased correspondingly with increase in storage days. Four genera of fungi (<em>Aspergillus, Penicillium, Rhizopus </em>and <em>Mucor</em>)<em> </em>were isolated from fruits of both <em>Irvingia </em>species, and <em>I. wombolu </em>was found to sustain a significantly lower fungal population (7.76E+07 cfu) than <em>I. gabonensis </em>(1.05E+08 cfu)<em>. </em>High fungal population led to a correspondingly high severity of brownish-black rot disease. Fruits of both<em> </em><em>Irvingia </em>species<em> </em>possessed all five phytochemicals (alkaloids, flavonoids, saponins, tannins and glucosides). However, whilst both species had the same amounts of flavonoids and glycosides, <em>I. wombolu</em> possessed relatively higher amounts of alkaloids, saponins and tannins than <em>I. gabonensis</em>. <em>I. wombolu </em>may be the preferred choice if domestication would be based on phytochemicals. In like manner, <em>I. gabonensis </em>may be the preferred choice for domestication if taste, weight and size of fruits were the parameters of interest.</p>