Output risk aspects of genetically modified crop technology in South Africa

Technology involving genetic modification of crops has the potential to make a contribution to rural poverty reduction in many developing countries. Thus far, insecticide-producing 'Bt' varieties of cotton have been the main GM crops under cultivation in developing nations. Several studies have evaluated the farm-level performance of Bt varieties in comparison to conventional ones by estimating production technology, and have mostly found Bt technology to be very successful in raising output and/or reducing insecticide input. However, the production risk properties of this technology have not been studied, although they are likely to be important to risk-averse smallholders. This study investigates the output risk aspects of Bt technology using a three-year farm-level dataset on smallholder cotton production in Makhathini flats, Kwa-Zulu Natal, South Africa. Stochastic dominance and stochastic production function estimation methods are used to examine the risk properties of the two technologies. Results indicate that Bt technology increases output risk by being most effective when crop growth conditions are good, but being less effective when conditions are less favourable. However, in spite of its risk increasing effect, the mean output performance of Bt cotton is good enough to make it preferable to conventional technology even for risk-averse smallholders.

Review: intellectual property aspects of plant transformation

One of the recurring themes of the debates concerning the application of genetic transformation technology has been the role of Intellectual Property Rights (IPR). This term covers both the content of patents and the confidential expertise usually related to methodology and referred to as 'Trade Secrets'. This review explains the concepts behind patent protection, and discusses the wide-ranging scope of existing patents that cover all aspects of transgenic technology, from selectable markers and novel promoters to methods of gene introduction. Although few of the patents in this area have any real commercial value, there are a small number of key patents that restrict the 'freedom to operate' of new companies seeking to exploit the methods. Over the last 20 years, these restrictions have forced extensive cross-licensing between ag-biotech companies and have been one of the driving forces behind the consolidation of these companies. Although such issues are often considered of little interest to the academic scientist working in the public sector, they are of great importance in any discussion of the role of 'public-good breeding' and of the relationship between the public and private sectors.

Aspects of isolation underpinning mitotic behaviour in lupin protoplasts

This study reports on the influence of critical isolation factors on the subsequent culture of protoplasts of Lupinus albus L. Protoplasts were isolated from in vitro seedling cotyledons of five early maturing accessions in which protoplast yields and division frequencies appeared to be correlated as a high protoplast yield corresponded with a high division frequency. The overall difference among the accessions for mitosis was non- significant, although the highest yield and division frequency were observed in accession LA132, with Alban giving a significantly lower level. Accession Lucrop produced the lowest number of protoplasts, all of which collapsed during culture. Of the enzyme types used for tissue maceration, Pectolyase Y23, was significantly inferior to Macerase in terms of giving way to mitosis. The extent of division in Macerase- isolated protoplast population was 266% higher than that in the Pectolyase Y23- isolated one. The physiological maturity level of the explant, expressed in terms of developmental age, was optimal when 14 - 18- day- old seedling cotyledons were used for protoplast production and culture, rather than more mature ones, despite higher protoplast yields in the latter. On K8p medium, the protoplast division frequency was 129% greater when 18- day- old seedling cotyledons were used, than that with any other treatment. This work on protoplast culture of the potentially important lupin species, which is a pulse rich in dietary protein, oil and fibre, allows a further understanding of the biology, with an aim to advance lupin biotechnology.

Analytical and compositional aspects of isoflavones in food and their biological effects

This paper provides an overview of analytical techniques used to determine isoflavones (IFs) in foods and biological fluids with main emphasis on sample preparation methods. Factors influencing the content of IFs in food including processing and natural variability are summarized and an insight into IF databases is given. Comparisons of dietary intake of IFs in Asian and Western populations, in special subgroups like vegetarians, vegans, and infants are made and our knowledge on their absorption, distribution, metabolism, and excretion by the human body is presented. The influences of the gut microflora, age, gender, background diet, food matrix, and the chemical nature of the IFs on the metabolism of IFs are described. Potential mechanisms by which IFs may exert their actions are reviewed, and genetic polymorphism as determinants of biological response to soy IFs is discussed. The effects of IFs on a range of health outcomes including atherosclerosis, breast, intestinal, and prostate cancers, menopausal symptoms, bone health, and cognition are reviewed on the basis of the available in vitro, in vivo animal and human data.