Anthocyanins, which give berryfruit their characteristic colour, have attracted the interest of researchers because of their putative health benefits. Over the past eight years, HortResearch has been analysing the anthocyanin content of numerous samples of different species of Vaccinium, Rubus and also Ribes nigrum. These samples were taken from different genotypes held in germplasm collections, cultivar and advanced selection trials, genetic studies and seedling populations. Averaged over all samples, Ribes had higher total anthocyanin contents (total ACY) than Vaccinium which was, in turn, higher than Rubus. However, all genera provided rich sources of anthocyanins and individual crop types within genera varied considerably. Five percent (i.e., 223) of our samples had total ACY of more than 5000 microg/g: most of these were blackcurrants, but some were black raspberries and three were ornamental blueberries. Vaccinium species generally contained the most diverse range of individual anthocyanins. In contrast, Ribes nigrum samples were dominated by cyanidin and delphinidin rutinosides which, on average, comprised almost 80% of the total ACY. For Rubus species almost all anthocyanins were cyanidins, although which ones were more prevalent varied with the species. The high degree of variation in total ACY and individual anthocyanin contents reported herein, coupled with the moderate to high heritabilities reported in the literature, indicate that good progress could be made in breeding cultivars with still higher total ACY levels.

Background The skin (exocarp) of fleshy fruit is hugely diverse across species. Most fruit types have a live epidermal skin covered by a layer of cuticle made up of cutin while a few create an outermost layer of dead cells (peridermal layer). Results In this study we undertook crosses between epidermal and peridermal skinned kiwifruit, and showed that epidermal skin is a semi-dominant trait. Furthermore, backcrossing these epidermal skinned hybrids to a peridermal skinned fruit created a diverse range of phenotypes ranging from epidermal skinned fruit, through fruit with varying degrees of patches of periderm (russeting), to fruit with a complete periderm. Quantitative trait locus (QTL) analysis of this population suggested that periderm formation was associated with four loci. These QTLs were aligned either to ones associated with russet formation on chromosome 19 and 24, or cuticle integrity and coverage located on chromosomes 3, 11 and 24. Conclusion From the segregation of skin type and QTL analysis, it appears that skin development in kiwifruit is controlled by two competing factors, cuticle strength and propensity to russet. A strong cuticle will inhibit russeting while a strong propensity to russet can create a continuous dead skinned periderm.

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Experiments are described which support the application of the membrane theory of shell analysis in determining optimum shapes for underwater structures of constant strength. A relationship between marine life and such structures is considered and design procedures for shape selection are given. Proposals for the investigation of the behaviour of such structures under loadings otherthan the initial design forces are outlined both from an analyticaIJnumerica1 and an experimental approach.

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