Search

The phenotypic diversity of 32 landrace populations of tetraploid wheats originating from the Bale and Wello regions of Ethiopia was studied. Eight heritable qualitative traits (glume hairiness, glume colour, awnedness, awn length, beak awn, awn colour, spike density, seed colour) were measured on 2453 individual plants (45–110 plants per landrace). The frequencies of each phenotypic class were used to estimate and analyse the diversity at different levels (population, altitude, region). Beak awn and seed colour showed the highest diversity index, and glume hairiness the lowest. Glume hairiness, glume colour, beak awn and awn colour were regionally variable, while gradients across altitude were observed for glume hairiness, glume colour and beak awn. Variation was, however, largely due to the differences in the level of the different characters within populations. On a regional basis, a higher mean diversity index was observed for materials from Wello than from Bale. No drastic change in the overall diversity between these collections and those analysed in the 1970s was evident.

Variation within the gene for the proinflammatory cytokine interleukin (IL)-18 has been associated with inter-individual differences in levels of free protein and disease risk. We investigated the frequency of function-associated IL18 gene haplotypes in an extensive sample (n=2357) of African populations from across the continent. A previously identified five tagging SNP (single-nucleotide polymorphism) haplotype (here designated hGTATA), known to be associated with lower levels of IL-18, was observed at a frequency of 27% in a British population of recent European ancestry, but was found at low frequency (