Isolation and mapping of genome-wide resistance (R) gene analogs (RGAs) is of importance in identifying candidate(s) for a particular resistance gene/QTL. Here we reported our result in mapping totally 228 genome-wide RGAs in maize. By developing RGA-tagged markers and subsequent genotyping a population consisting of 294 recombinant inbred lines (RILs), 67 RGAs were genetically mapped on maize genome. Meanwhile, in silico mapping was conducted to anchor 113 RGAs by comparing all 228 RGAs to those anchored EST and BAC/BAC-end sequences via tblastx search (E-value < 10(-20)). All RGAs from different mapping efforts were integrated into the existing SSR linkage map. After accounting for redundancy, the resultant RGA linkage map was composed of 153 RGAs that were mapped onto 172 loci on maize genome, and the mapped RGAs accounted for approximate three quarters of the genome-wide RGAs in maize. The extensive co-localizations were observed between mapped RGAs and resistance gene/QTL loci, implying the usefulness of this RGA linkage map in R gene cloning via candidate gene approach.

Spodoptera frugiperda is a notorious pest that feeds on more than 80 crops, and has spread over 100 countries. Many biological agents have been employed to regulate it, such as Arma custos. A. custos is a polyphagous predatory heteropteran, which can effectively suppress several agricultural and forest pests. Thus, in order to understand where A. custos can survive and where can be released, MaxEnt was used to predict the potentially suitable areas for A. custos in China under climate change conditions. The results show that the annual mean temperature (bio1) and annual precipitation (bio12) are the major factors influencing the distribution of A. custos. The optimal range of the two are 7.5 to 15 °C, 750 to 1200 mm, respectively. The current climate is highly suitable for A. custos in Hebei, Henan, Shandong, Anhui, Hubei, Jiangsu, and Zhejiang Provinces. Considering the currently suitable distribution area of S. frugiperda, artificially reared A. custos is suitable for release in Fujian, Zhejiang, Jiangxi, Hunan, and southeastern Sichuan Provinces. Under the future climatic scenarios, the suitable area will decrease and shift towards the north. Overall, this result can provide a reference framework for future application of A. custos for biological control.

The Qinghai–Tibetan Plateau is the highest plateau in the world and is sensitive to climate change. The dynamics of soil enzyme activities and microbial communities are good indicators of alpine biochemical processes during warming. We collected topsoil (0–10 cm) and subsoil (10–20 cm) samples at altitudes of 3200–4000 m; determined the activities of β-1,4-glucosidase (BG), cellobiohydrolase (CBH), β-1,4-N-acetyl-glucosaminidase (NAG) and acid phosphomonoesterase (PME); and performed Illumina 16S rRNA high-throughput sequencing. We found that the soil carbon (total organic carbon and dissolved organic carbon) and nitrogen (total nitrogen and dissolved organic nitrogen) fluctuated with altitude in both the topsoil and subsoil, whereas the dissolved phosphorus continuously decreased with the increasing altitude. BG and CBH decreased from 3200 to 3600 m and increased from 3800 to 4000 m, with the lowest levels occurring at 3600 m (topsoil) and 3800 m (subsoil). NAG and PME showed similar fluctuations with altitude, with the highest levels occurring at 3400 m and 4000 m in both the topsoil and subsoil. Generally, the altitudes from 3600 to 3800 m were an ecological transition belt where most of the nutrients and enzyme activities reached their lowest levels. All of the alpine soils shared similar dominant phyla, including Proteobacteria (32.7%), Acidobacteria (30.2%), Actinobacteria (7.7%), Bacteroidetes (4.4%), Planctomycetes (2.9%), Firmicutes (2.3%), Gemmatimonadetes (2.0%), Chloroflexi, (1.2%) and Nitrospirae (1.2%); Gemmatimonadetes and Verrucomicrobia were significantly affected by soil depth and Planctomycetes, Firmicutes, Gemmatimonadetes, Nitrospirae, Latescibacteria and Armatimonadetes were significantly affected by altitude. In addition, nutrient availability, enzyme activity and microbial diversity were higher in the topsoil than in the subsoil, and they had more significant correlations in the subsoil than in the topsoil. Our results provide useful insights into the close linkages between soil nutrient cycling and microbial activities on the eastern Qinghai–Tibetan Plateau, and are of great significance for further assessing the long-term impact of environmental changes in the alpine ecosystems.

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The pigment is an important character in plant development. In the present study, we characterized and fine mapped one inhibitor for brown furrows gene (ibf) in rice (Oryza sativa L.). In the ibf mutant, brown pigments specifically accumulate in the furrows of hulls as seeds mature and reach a maximum level in dry seeds. Genetic analysis showed that the mutant phenotype is controlled by one recessive nuclear gene, which was finally mapped in a 90-kb region on the long arm of chromosome 9. Polymerase chain reaction and Southern blotting analysis revealed that there was a 26 kb deletion in the 90-kb region in the mutant. Since all the open reading frames outside the gap in the delimited region had no detectable difference in DNA sequence with the wild-type, we postulated that the ibf locus should be located in the gap. Through gene annotation and reverse transcription-polymerase chain reaction (RT-PCR) analysis, we selected OsKF1 encoding a kelch repeat-containing F-box family protein as the candidate gene of ibf.In most species, the coloration of flowers and fruits is due to the accumulation of flavonoid pigments (Quattrocchio et al. 2006). Understanding of the role of flavonoids as the major red, blue, purple and brown pigments in plants has attracted considerable interest over the years (Winkel-Shirly 2001). Flavonoids are plant secondary metabolites derived from the phenylpropanoid pathway and play a number of roles such as response to pathogens, protection from UV radiate and germination of pollen tubes. The major forms, which are anthocyanins (red to purple pigments), flavonols (colorless to pale yellow pigments) and proanthocyanidins also known as condensed tannins (colorless pigments that brown with oxidation) vary in proportion and amount according to the plant species, the organs, the stage of development and growth conditions (Debeaujon et al. 2001;Devic et al. 1999).In Arabidopsis, the flavonoid pathway has been mainly characterized using mutants which showed altered seed color for its seeds being characterized brown color (Debeaujon et al. 2001). To date, more than 20 loci involved in the flavonoid pathway have been characterized and seventeen genes have been