Characterization of kenaf (Hibiscus cannabinus L.) cultivars in South Africa
MetadataShow full item record
Kenaf (Hibiscus cannabinus L.) is one of the world’s most economically important fibre crops. The traditional use of kenaf focuses on its fibre production, for the making of products such as ropes, sacks, canvases, and carpets. New applications of kenaf have been developed such as pulping and papermaking, board making, filtration media, potting media, animal feed, and oil absorption. The fibres are also processed for use in the automotive industry. Kenaf was introduced to South Africa during the last few years. The crop is being explored as a potential commercial crop for fibre production in South Africa. · The objectives of this study were to conduct glasshouse and field trials on commercial kenaf cultivars to evaluate morphological and agronomic differences between them; to compare the oil content and fatty acid composition of the seed of eight cultivars; to determine genetic relationships between commercial cultivars and nine wild type varieties and to determine the genotype x environment (G x E) interactions and stability of commercial cultivars. · Seeds were obtained from several sources and sown directly into pots. Seedlings were grown in a heat-controlled glasshouse. A field trial was also planted in another location. These plants were used in various investigations. · Two field trials were planted in two different locations to determine the G x E interactions. The experimental designs were complete randomised blocks with four replications. Eight morphological and agronomic characters studied were subjected to an ANOVA and significant differences were found for some traits between cultivars tested in the glasshouse. Significant differences also occurred among replications for some traits in both trials. There were not many morphological differences between cultivars and therefore it is difficult to identify individual cultivars merely by morphological characters. · Seeds of eight cultivars were used to determine the oil content and fatty acid composition of the seed oil. The percentage oil was relatively high for all cultivars; however, there was not much difference between cultivars for oil content. The percentages of each fatty acid varied greatly among different cultivars and therefore there is a potential for genetic improvement in oil quality. · AFLP analysis was used fingerprint commercial cultivars and three wild type varieties. Six primer combinations between EcoR I and Mse I were used to determine genetic relationships. A total of 406 fragments were generated, of which 229 (56.4%) were polymorphic. A low level of genetic diversity was detected in kenaf genotypes. · Separate and combined analyses of variance across locations, three types of stability parameters and correlation analyses were performed. · The separate trial analyses for two locations have shown significant differences among cultivars for three yield traits. With the exception of plant length, there were no significant differences between replications. The combined analysis of variance across locations showed highly significant differences among locations for three yield traits. There were, however, no significant differences among genotypes and their interactions with localities for three traits. All cultivars performed on average better in location 1 (under irrigated conditions) for six measured traits. According to Wricke’s (1962) ecovalence, El Salvador, Everglades 41, and SF 459 were the most stable cultivars for the three yield traits respectively. Lin and Binns’ (1988) cultivar superiority measure indicated that El Salvador and Tainung 2 were the most stable cultivars for the three traits. Nassar and Huehn’s (1987) non-parametric measure of stability revealed that El Salvador and SF 459 had the smallest changes in ranks and thus were the most stable cultivars.