Virulence of colletotrichum kahawae strains and their effect on resistant arabica coffee varieties in Tanzania

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dc.creatorKilambo, Deusdedit Lucian
dc.date.accessioned2014-10-14T09:38:53Z
dc.date.accessioned2025-08-05T07:38:59Z
dc.date.available2014-10-14T09:38:53Z
dc.date.created2014-10-14T09:38:53Z
dc.date.issued2008
dc.description.abstractThe virulence of 26 Colletotrichum kahawae strains collected from different coffee growing areas in Tanzania was studied under laboratory conditions. Cultural and morphological characters on malt extract agar indicated variations amongst strains. Virulence tests both on detached coffee green berries and hypocotyls distinguished between highly and less virulence strains. Initial symptom appearance showed positive correlation to sporulation. Lesion size showed positive correlation to sporulation capacity and percent berry infection; and sporulation capacity and percent berry infection. At 15 0 C the virulence of C. kahawae strains was higher than at 20 0 C and 25 0 C. Biochemical test using esterases, acid phosphatases and alkaline phosphatases iso-enzymatic systems studied by iso-electric focusing revealed variation among Tanzanian C. kahawae strains from those obtained from other countries. Percent germination of conidia on wax surface extracts from green berries of resistant coffee genotypes indicated that the wax layer influences resistance to C. kahawae. Post-penetration growths of C. kahawae in hypocotyls measured at 24, 48 and 72 hrs after inoculation were higher in susceptible than resistant genotypes. Histological characterization of coffee genotypes revealed inhibition of fungal growth by callose formation around intracellular hyphae in resistant genotypes. Expression of coffee resistance to C. kahawae varied with the test isolates and the hybrids. However, coffee genotype 20498 (L2) showed the highest level of resistance to C. kahawae.
dc.identifierKilambo, D.L. (2008). Virulence of colletotrichum kahawae strains and their effect on resistant arabica coffee varieties in Tanzani. Morogoro : Sokoine University of Agriculture
dc.identifierhttps://www.suaire.sua.ac.tz/handle/123456789/199
dc.identifier.urihttp://repository.costech.or.tz/handle/20.500.14732/99219
dc.languageen
dc.publisherSokoine University of Agriculture
dc.subjectColletotrichum kahawae
dc.subjectCoffee growing
dc.subjectArabica coffee
dc.subjectResistant arabica coffee
dc.subjectCoffee varieties
dc.subjectTanzania
dc.titleVirulence of colletotrichum kahawae strains and their effect on resistant arabica coffee varieties in Tanzania
dc.typeThesis

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