ISHS Acta Horticulturae 602: VI International Protea Research Symposium
ELSINOË SCAB RESISTANT LEUCOSPERMUM AND PRELIMINARY USE IN HYBRIDIZATION |
| Authors: | G.M. Littlejohn, G. van den Berg, K. Lubbe |
| Keywords: | Proteaceae, pincushion, disease scoring, controlled hand-pollination, seed set |
| Abstract:
Production of Southern African Proteaceae for fresh cut flower purposes within their natural habitat exposes the production plantations to high disease pressure, as sources of infection are always present in surrounding natural vegetation. Disease resistance is the most environmentally effective method of controlling disease within plantations. Elsinoë scab disease on Leucospermum causes unsightly stem and leaf lesions. It was observed in the genebank plantations at Elsenburg that Leucospermum ‘High Gold’ did not become infected in the field. This instigated the development of a screening technique for Elsinoë scab disease, and the screening of different genotypes within and between species of Leucospermum within the ARC Fynbos Genebank collection to clarify the field resistance of ‘High Gold’ and identify other possible sources of resistance. The genotypes screened to date reveal a spectrum of responses to infection, ranging from severe stem lesions without leaf lesions, to leaf and stem lesions, and to no infection. The results indicate a complex interaction between the genotype of the host and the pathogen. Resistant, partially resistant and susceptible genotypes have been successfully hybridized in a diallel, resulting in progeny seed that will be screened in future and the data used to deduce genetic control of resistance. | |
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