Pepper (Capsicum sp.) is important in human diets in many parts of the world and a major source of several antioxidants, including carotenoids, ascorbic acid, tocopherols and phenolics. More information on genetic diversity within Capsicum for antioxidant (AO) content and antioxidant activity (AOA) could contribute to improved human health. We evaluated 46 Capsicum accessions from AVRDC-the World Vegetable Center Capsicum core collection for content of nine AO (five carotenoids, ascorbic acid, tocopherols a and g, and total phenolics) and two AOA assays for 2 years in south Taiwan. Ample genetic diversity exists within C. annuum to increase AO content. Based on dry weight values, non-pungent C. annuum entries as a group were significantly greater than pungent entries for contents of b-cryptoxanthin (36%), ascorbic acid (65%), total phenolics (36%) and a-tocopherol (11%). Group means of the brown-fruited entries exceeded the means of red-fruited entries for capsanthin (34%), zeaxanthin (37%), lutein (36%), b-cryptoxanthin (71%), b-carotene (82%), ascorbic acid (19%) and a-tocopherol (40%). Red-fruited C. annuum entries 'Verdano Poblano' and 'Guajillo Ancho' from Mexico ranked among the entries highest for all carotenoids, ascorbic acid and a-tocopherol. The inhibition of lipid peroxidation (ILP) assay could be adopted for AOA characterization or selection because of high variation among entries and consistent entry performance over years. ILP was positively correlated with phenolics (r ¼ 0.72**) and ascorbic acid (r ¼ 0.58**) contents. Significant positive correlations were detected between most carotenoids as well as a significant positive correlation between ascorbic acid and total phenolics contents (r ¼ 0.78**).

Evaluation of 381 sweet potato cultivais and 464 breeding lines for root yield under drought stress and minimum input conditions following a rice crop revealed certain genotypes that surpassed the tropical Asian yield average by at least 100%. Such genotypes appeared to possess both drought tolerance and good yielding ability.