REVIEW - A reference data set for retinal vessel profiles

This paper describes REVIEW, a new retinal vessel reference dataset. This dataset includes 16 images with 193 vessel segments, demonstrating a variety of pathologies and vessel types. The vessel edges are marked by three observers using a special drawing tool. The paper also describes the algorithm used to process these segments to produce vessel profiles, against which vessel width measurement algorithms can be assessed. Recommendations are given for use of the dataset in performance assessment. REVIEW can be downloaded from http://ReviewDB.lincoln.ac.uk

Seed coat phytochemistry of both resistant and susceptible seeds affords some protection against the granivorous beetle Callosobruchus maculatus

The seed coat lies at the interface between the internal structures of the seed and the external environment and thus represents a key arena in the study of seed-herbivore interactions. Callosobruchus maculatus is a cosmopolitan pest of legume seeds, and under post-harvest conditions, females interact directly with the seed testa prior to laying their eggs. Here we investigate the effect of chemical extracts of the seed coat of the resistant Phaseolus vulgaris and the susceptible Vigna unguiculata beans on egg laying preferences and larval development of C. maculatus. Seed coat extracts contained phenolic, glycoside and alkaloid compounds. Upon re-incorporation of extracts into artificial host beans it was found that that several seed coat extracts from both the resistant and susceptible varieties reduced female oviposition and disrupted larval growth and development. However, none of the extracts assayed resulted in complete ovipositional or developmental failure suggesting that complete resistance in P. vulgaris is derived from other physical or chemical properties of the seed and/or seed coat that function either alone or synergistically. Further work is required to elucidate the importance of synergistic interactions between different physiological defence mechanisms on overall plant (seed) resistance

The role of seed coat thickness in resistance/susceptibility of legumes to cowpea beetle (Callosobruchus maculatus) infestation

The role of seed coat thickness in the resistance/susceptibility of V. unguiculata (black-eyed beans, Cultivar: Black-eyed peas) against infestation by the bruchid beetle C. maculatus (F.), was investigated. Decoated V. unguiculata beans were individually coated in one to four of previously removed seed coats or one layer of Phaseolus vulgaris (Red Kidney Beans-British Type) seed coat, before being offered to non-virgin C. maculatus females to oviposit on. Following incubation for several weeks, the total adult emergence was then used to determine egg-adult survival and the seed coat thickness for both types of beans was measured. The seed coat of P. vulgaris was approximately three times thicker than that of V. unguiculata. The survival of larvae in the four coats V. unguiculata treatment was similar to that of P. vulgaris seed coat, which showed the high correlation of seed coat thickness with V. unguiculata beans resistance to C. maculatus.</p