As selenium and carotenoids are essential micronutrients, the determination of their concentrations in different varieties is important in the breeding of foxtail millet (Setaria italica L. P. Beauv.). To identify selenium- and carotenoid-enriched foxtail millet varieties and to analyze correlations between trace elements and agronomic traits, we measured the selenium and carotenoid concentrations of 200 Chinese accessions by high-performance liquid chromatography and atomic fluorescence spectrometry. Our analysis revealed that lutein concentration in 200 foxtail millet accessions followed normal distribution and average was 3.1 μg g^–1. The mean value of zeaxanthin concentration in 200 accessions was 8.6 μg g^–1. Lutein and zeaxanthin concentrations were higher in the foxtail millet from Liaoning than in varieties from other locations, with averages of 10.0 and 3.5 μg g^–1, respectively. The average measured selenium concentration was 100.3 μg kg^–1. The highest average selenium concentration, 110.3 μg kg^–1, was found in varieties from Shanxi. Varieties from Inner Mongolia had the lowest average selenium concentration, 84.7 μg kg^–1, which was significantly lower (P<0.05) than that of Shanxi. Selenium concentrations of 23 varieties were higher than 117.9 μg kg^–1, accounting for 11.5% of the total, thereby were considered to be enriched in selenium. In addition, we identified 29 lutein-enriched varieties (>4.27 μg g^–1) and 30 zeaxanthin-enriched ones (>12.63 μg g^–1), which corresponded to 14.5 and 15% of tested accessions, respectively. Correlation analysis revealed that selenium concentration was significantly positively correlated with spikelet length (P<0.01), while zeaxanthin concentration was significantly correlated with grass weight (P<0.05) and spikelet length (P<0.01). No correlation was found between lutein concentration and agronomic characters, selenium content or zeaxanthin content. Our results should contribute substantially to the selection of suitable varieties for the development of plants with desired levels of these nutritionally important elements. These results will significantly contribute towards selection of the most suitable varieties for obtaining plants with desired levels of these nutritionally important elements.

The presence of abundant and diverse communities of macro-arthropods is considered an indicator of sustainability in agroecosystems. This study was designed to investigate the effects of different fertilizer treatments on abundance and diversity of insects of arable loess soil on the Loess Plateau of China. These regimes included a control with no fertilizer addition or manure, treatments with application of mineral fertilizers (N, NK, NP, PK, NPK), treatments with NPK in combination with organic materials such as wheat straw or maize stalk, treatments with two rates of organic manure application; and different crop rotations (Rot.1: winter wheat summer maize; Rot.2: winter wheat summer maize soybean intercropping; and Rot.3: winter wheat or rapeseed summer maize soybean intercropping). Soil macro-arthropods were collected from the plough layer (0-20 cm) and sorted by hand after each harvest in June and October 2001 and 2002. A total of 3 132 individuals were collected, from 7 orders and 55 families, dominated by Formicidae (61.72%) and Staphylinidae (14.24%). The results showed that individuals and groups were significantly influenced by sampling dates, while groups were significantly influenced by the fertilization treatments. Soil insect biodiversity, as determined by the Shannon index, was significantly influenced by fertilization and sampling dates. The abundance of soil insects was positively and significantly correlated with soil moisture content in October 2002. Nitrogen, phosphorus and potassium fertilizers and incorporation of organic materials were favorable factors for abundance and diversity in arable loess soil.