Characterization of Opuntia ficus-indica cultivars in South Africa

English: Spineless cactus pear [Opuntia ticus-indice (L.) MilL] in South Africa is increasingly commercialised and there is a need to establish a database to assist the South African farmers in the selection of cultivars for production. The aim of this study was to contribute to such a database on horticultural, fodder, genetical and pathoglogical level. 2. Plantmaterial of the 10 cultivars were obtained from a genebank situated near Potgietersrus in the Northern Transvaal (230 50'S), South Africa. This area has a subtropical climate with predominantly summer rainfall. The cultivars were characterised on general horticultural characteristics, characteristics for use as fodder and resistance to four pathogens obtained from infected cactus pear orchards in South Africa. The cultivars were also genetically characterised using the AFLP method. 3. All the morphological results obtained were compared with the genetical data. The results obtained showed that morphological data, whether horticultural, fodder or pathological, are inadequate to distinguish and characterise the different cultivars. DNA fingerprinting can complement this characterisation. 4. The fact that the major clustering in the morphological and pathological dendrograms does not correlate with the AFLP dendrogram proves that low correlation exist between the subset of DNA related to morphological characters, the subset of DNA related to pathology and a random sampling of the total genomic DNA. It also underlines the unreliability of using only morphological and pathological descriptors in selection. In order to solve this problem, further description and characterisation of these cultivars is needed, but in the different cactus pear production areas in South Africa in order to better understand the influence of the environment on these cultivars. Description and characterisation of the cultivars in terms of a wider set of parameters, for instance resistance to a wider range of pathogens and cold tolerance is also needed in order to make the morphological and pathological data more reliable. 5. It is clear from the literature that O. ficus-indice is a multifunctional crop, which can be of great value in both developed en undeveloped countries, because of its ability to utilise the full potential of arid areas, though in South Africa the full potential of cactus pear is not utilised yet. It is clear from the morphological and pathological data in this study that the 10 commercial cultivars in South Africa compare well to other cultivars described in the literature.