Tylosema

Abstract: Pycnostigmus rostratus Cameron, 1905, is redescribed and four new species of Pycnostigmus are described: P. mastersonae Buffington & van Noort, new species; P. incognito Buffington & van Noort, new species; P. fossilensis Buffington & van Noort, new species; and P. hoerikwaggoensis Buffington & van Noort, new species. Pycnostigmus mastersonae is the only known species of Cynipoidea with a metallic sheen on the head and mesosoma. A redescription of Tylosema nigerrimum Kieffer, 1905, is provided as well as the description of two new species: Tylosema dayae Buffington & van Noort, new species and Tylosema ronquisti Buffington & van Noort, new species. The discovery of two new species of Tylosema in South Africa is noteworthy since the only previously known species, T. nigerrimum Kieffer, is from Algeria. A redescription of Trjapitziniola popovi (Belizin 1951) is provided as well as the description of one new species: Trjapitziniola vanharteni Buffington & van Noort, new species. Trjapitziniola vanharteni was collected in the United Emirates Republic, which extends the distribution of Trjapitziniola well into the Arabian Penninsula. An online key to World species of Pycnostigminae and images are available at www.waspweb.org/Cynipoidea/Figitidae/Pycnostigminae/ index.htm, and images of all species contained within this paper are available from http://morphbank.net.

Abstract: Tylosema fassoglensis seeds contain high levels of lipids (240-300 g kg -1 ) and proteins (446 g kg -1 dry weight). Major fatty acids contained in the oil are linoleic (36-42% of the total fatty acids) oleic (32-35%) and palmitic (11.5-15.7%) acids. The proteins are characteristic with their high levels of lysine, proline and tyrosine. Due to their very low content, both methionine and cystine appear to be the limiting amino acids. Tylosema fassoglensis defatted meal contains substantial amounts of trypsin inhibitors and phytates 295 TUI mg -1 and 35 g kg -1 dry weight, respectively

Abstract: The alternative fuels debate continues to attract the attention of researchers and scientists globally. This paper reports experimental results on selected properties of biodiesel derived from Tylosema Esculentum kernel oil and compares them with similar properties of petroleum diesel to assess its suitability for use as fuel in diesel engines. Results indicate an ester content of 90% for tylosema biodiesel fuel, while its viscosity profile meets requirements of American standards for biodiesel fuel (ASTM D 6751-02). The flash point and cold flow properties of tylosema biodiesel were found to be typical of a biodiesel fuel, while its acidity is within range of both American and European standards by 72.5%, and 56% respectively. It was also observed that biodiesel engine performance is marginally better than that of petroleum diesel, with lower concentrations of hydrocarbon emissions. Levels of carbon dioxide and carbon monoxide (CO) are largely comparable to those of petroleum diesel.

Abstract: Marama bean [Tylosema esculentum (Burchell) L. Schreiber] is an under-utilized non-nodulating legume, native to the arid and semi-arid areas of Southern Africa, including Namibia, South Africa and Botswana. Its primary benefit to man is based upon the high nutritional value of the seeds. The protein content is slightly higher than that of soybeans and the oil content is twice that of soybeans and approaches that of peanuts. There is an increasing interest in its cultivation, due to its potential as a cash crop and food source, especially in the face of climate changes. In this study, the intergenic spacers (IGS) region of the large ribosomal DNA gene was amplified to assess length variation in Marama bean. A pair of primers based in the conserved ribosomal DNA coding region, but both reading out the coding region, was used to amplify the IGS that separates the repeat units within the tandem arrays of the ribosomal DNA (rDNA) genes. A total of 79 scorable bands were generated by the primer pair used, of which 7 alleles were polymorphic. The rDNA genes proved to be a useful tool for identifying the genetic variation of Marama bean which will be the basis of its effective domestication. Key words: Marama bean genetic diversity, rDNA gene, intergenic spacer,Tylosema esculentum.