Food security: the challenge of feeding 9 billion people.

Continuing population and consumption growth will mean that the global demand for food will increase for at least another 40 years. Growing competition for land, water, and energy, in addition to the overexploitation of fisheries, will affect our ability to produce food, as will the urgent requirement to reduce the impact of the food system on the environment. The effects of climate change are a further threat. But the world can produce more food and can ensure that it is used more efficiently and equitably. A multifaceted and linked global strategy is needed to ensure sustainable and equitable food security, different components of which are explored here.

The mental wealth of nations.

Countries must learn how to capitalize on their citizens' cognitive resources if they are to prosper, both economically and socially. Early interventions will be key.

DNA patenting: the end of an era?

Debates on patenting DNA must evolve to reflect the global decline in filings and regional disparities in patenting activity.

Society and ethics - the genetics of disease.

Established guidance for the protection of human subjects in research has provided the framework for research and clinical practice in genetics. Three key principles to emerge are the requirements for consent, privacy and confidentiality. However, recent research on genetic susceptibility to common diseases indicates that it may be more difficult to decide if and when genetic testing will be appropriate. Risks of disease may be low and interventions may not be available. Today, debate is primarily focussed on ethical issues raised by the use and storage of genetic information. One of the earliest experiences of genetic testing for some people is likely to be in the area of pharmacogenetics. Debate about ethical issues has been focused on the implications of patient stratification, particularly with regard to the availability of medicines for small groups and the significance of racial variation in response to medicines. The possible use of personal genetic information by insurance companies and employers has also been an issue that legislators have taken seriously.

Functional heterostyly in Tylosema esculentum (Caesalpinioideae).

Tylosema esculentum is a long-lived perennial species endemic to arid areas of southern Africa. Its potential as a crop species has long been recognized as a result of the high oil and protein content of its seeds. The reproductive biology and breeding systems of the species were investigated in wild and experimental populations growing in Botswana. Field observations confirmed that the species is heterostylous with the pistil and anthers exhibiting reciprocal heights in the two morphs, although pollen size and sculpturing do not vary. The wet, nonpapillate stigma characteristic of the species is the first to be reported in the Caesalpinioideae. In vivo and in vitro diallel crossing experiments demonstrated that a diallelic self-incompatability system exists in T. esculentum. The major site of pollen tube inhibition in the intramorph crosses was found to be in the style. This is the first report of functional heterostyly in the Fabaceae and of a confirmed self-incompatibility system in the Caesalpinioideae. Three separate lines of evidence, the monitoring of fruit development in open-pollinated plants, fruit set in diallel crossing experiments, and observations made in wild populations, demonstrated that fruit set and, by implication, seed set, are very low in this species. Floral abscission was a major limitation to the production of mature pods but there were also significant losses at other developmental stages of fruit production. The results suggest that low seed set may be an adaptation of the species to an environment in which rainfall is scarce.