Pearl millet (Pennisetum glaucum (L.) R. Br.) is an important staple cereal cultivated in the arid and semi-arid tropics of Asia and Africa, regions severely affected by malnutrition. Knowledge about the extent of genetic variability and patterns of agro-morphological variation in local germplasm from a target region is an important prerequisite for efficient crop improvement. To assess the potential of Sudanese pearl millet landraces as sources of desirable traits for pearl millet improvement including biofortification, a total of 225 accessions were evaluated in Sudan at three locations for agro-morphological traits and at one location for grain mineral nutrient contents (Fe, Zn, Ca, P, K, Mg, Mn, S, Na, Cu and β-carotene). Genetic variation was highly significant, but relatively limited for some agro-morphological traits (62–78 d to flowering, 119–188 cm plant height and 16–34 cm panicle length), pointing to the potential usefulness of a targeted diversification for these traits. Self-pollinated grain micronutrient contents showed a wide variation: 19.7–86.4 mg/kg for Fe and 13.5–82.4 mg/kg for Zn. Significant and positive correlations among most of the nutritional traits were observed; therefore, enhancement of the concentrations of some nutrients will lead to the improvement of other related nutrients. No significant associations were observed between the nutritional and agro-morphological traits, indicating good prospects for simultaneous improvement of both trait categories. No clear patterns of geographic differentiation for specific traits were detected for the Sudanese pearl millet. Nutrient-rich accessions were identified and those with acceptable agro-morphological traits are encouraging materials for future pearl millet biofortification programmes in Sudan.

Allozyme electrophoresis was used to assess genetic variability and differentiation in 22 populations of Gressittacantha terranova Wise (Hexapoda, Collembola) from a coastal area of Victoria Land between the Mariner Glacier and the Nansen Ice Sheet. Allelic frequencies were determined at five enzyme loci: Phi, Pgm, Hk, Mpi and Mdh. Levels of variability, estimated as rates of heterozygosity, were higher than those calculated for the same loci in taxonomically related and non-related species of non-Antarctic Collembola. Thus, in spite of the ecological simplicity of Antarctic terrestrial ecosystems, G. terranova is characterized by high levels of genetic variability, and the 22 populations could be divided into three geogaphic groups, separated by the Aviator and Campbell glaciers. Genetic differentaton reflects the geographic arrangement of the populations, suggesting that the glaciers are effective barriers to gene flow, and that the patchy distribution of collembolan species in Antarctica has the potential to induce, in the long term, microspeciation processes. Interestingly, detectable genetic differentiation was observed between six populations collected at Edmonson Point, even though these are very close to each other, indicating the impact of geographic isolation even within short distances. The only exception to the congruence between genetic and geographic structuring was provided by the population of Apostrophe Island, for which a recent introduction with individuals coming from southern populations is suggested.