Female adults of the migratory locust, Locusta migratoria manilensis (Meyen), can sense seasonal photoperiod changes, which induces embryonic diapause as a key strategy to overwinter.  Serine protease inhibitor genes (SPNs) were thought to play key roles during diapause, while few SPNs were functionally characterized.  LmSPN2 was one of those genes differentially expressed between diapause and non-diapause eggs; however, its biological function remained to be explored.  So, we conducted RNAi knockdown of LmSPN2, resulting in a significant decrease of the egg diapause rate by 29.7%.  Using yeast two-hybrid assays, co-immunoprecipitation, and pull-down methods, we found an interaction between LmSPN2 and LmSPN3, which was proved to be mediated by a glutamate (E331) binding site of LmSPN2.  RNAi knockdown of LmSPN3 resulted in a significant increase in diapause rate by 14.6%, indicating an inverse function of LmSPN2 and LmSPN3 on diapause regulation.  Double knockdown of two SPN genes resulted in a 26.4% reduction in diapause rate, indicating that LmSPN2 was the dominant regulatory signal.  Moreover, we found four Toll pathway genes (easter, spätzle, pelle, and dorsal) upregulated significantly after the knockdown of LmSPN2 while downregulated after the knockdown of LmSPN3.  Therefore, we speculate that two SPNs regulate diapause through the Toll pathway.  Our results indicated that LmSPN2 positively regulates locust egg entry into diapause, while LmSPN3 is a negative regulator of embryonic commitment to diapause.  Their interaction is mediated by the binding site of E331 and influences egg diapause through the Toll pathway.  This mechanistic understanding of diapause regulation expands our understanding of insect developmental regulation and provides functional targets for developing locust management strategies.

Grain size is a major determinant of grain weight and a trait having important impact on grain quality in rice. The objective of this study is to detect QTLs for grain size in rice and identify important QTLs that have not been well characterized before. The QTL mapping was first performed using three recombinant inbred line populations derived from indica rice crosses Teqing/IRBB lines, Zhenshan 97/Milyang 46, Xieqingzao/Milyang 46. Fourteen QTLs for grain length and 10 QTLs for grain width were detected, including seven shared by two populations and 17 found in one population. Three of the seven common QTLs were found to coincide in position with those that have been cloned and the four others remained to be clarified. One of them, qGS10 located in the interval RM6100–RM228 on the long arm of chromosome 10, was validated using F2:3 populations and near isogenic lines derived from residual heterozygotes for the interval RM6100–RM228. The QTL was found to have a considerable effect on grain size and grain weight, and a small effect on grain number. This region was also previously detected for quality traits in rice in a number of studies, providing a good candidate for functional analysis and breeding utilization.

Maize/peanut intercropping system shows the significant yield advantage. Soil microbes play major roles in soil nutrient cycling and were affected by intercropping plants. This experiment was carried out to evaluate the changing of rhizosphere microbial community composition, and the relationship between microbial community and soil enzymatic activities, soil nutrients in maize/peanut intercropping system under the following three treatments: maize (Zea mays L.) and peanut (Arachis hypogaea L.) were intercropped without any separation (NS), by half separation (HS) using a nylon net (50 μm) and complete separation (CS) by using a plastic sheet, respectively. The soil microbial communities were assessed by phospholipid fatty acid (PLFA). We found that soil available nutrients (available nitrogen (Avail N) and available phosphorus (Avail P)) and enzymatic activities (soil urase and phosphomonoesterase) in both crops were improved in NS and HS treatments as compared to CS. Both bacterial and fungal biomasses in both crops were increased in NS followed by HS. Furthermore, Gram-positive bacteria (G+) in maize soils were significant higher in NS and HS than CS, while the Gram-negative (G–) was significant higher in peanut soil. The ratio of normal saturated to monounsaturated PLFAs was significantly higher in rhizosphere of peanut under CS treatment than in any other treatments, which is an indicator of nutrient stress. Redundancy analysis and cluster analysis of PLFA showed rhizospheric microbial community of NS and HS of both plants tended to be consistent. The urase and Avail N were higher in NS and HS of both plants and positively correlated with bacteria, fungi (F) and total PLFAs, while negatively correlated with G+/G– and NS/MS. The findings suggest that belowground interactions in maize/peanut intercropping system play important roles in changing the soil microbial composition and the dominant microbial species, which was closely related with the improving of soil available nutrients (N and P) and enzymatic activities.

Agaricus blazei Murill is a well known edible/medicinal mushroom used for immune-nutrient food therapies. The biodegradation of different substrates with this fungus may result in different metabolites and degraded compounds, which may enrich the function of the food therapies. In this study, soluble compounds from the culture of A. blazei grown in liquid media with whole wheat bran and its water filtrate, respectively, were compared. Total soluble sugar, arabinoxylan, protein, and amino acids were significantly higher in the fungal culture resulted from the medium with whole wheat bran (43.54, 1.56, 0.59, and 2.19 mg mL-1, respectively) than that from the medium with the bran filtrate (17.28, 0.37, 0.13, and 1.13 mg mL-1, respectively). The biodegraded wheat bran with cultured mycelia was fed to Mus musculus Linnaeus as supplementation or as dietary fiber exclusive ingredient. As non-specific food therapies, feeding effects on mice intestinal development were indicated indirectly in growth performance, intestinal absorption and serum parameters. Compared to feeding uncultured wheat bran, feeding mice with culture mixes of A. blazei resulted in remarkably increase in villus height and villus height/crypt depth ratio, which were increased by 25.4 and 31.0%, respectively, when applied as supplementation, and by 44.3 and 43.4%, respectively, when applied as dietary fiber. These increases are concomitant with the higher level of D-xylose in blood serum about 16.9 and 29.2% as supplementation and dietary fiber, respectively. The results implying that culturing A. blazei with whole wheat bran enhanced extracellular metabolism of the fungus and extensive degradation of wheat bran insoluble fibrous compounds. Furthermore, feeding the culture mix including metabolites and degraded wheat bran improved intestinal villus development, proving the nutritional benefits of the A. blazei mycelial cultures.

Current study adopted gene flow theory and selection index method to compare the breeding efficiency of three breeding plans in the Chinese Holstein cattle using ZPLAN software. Simulated conventional progeny-testing program (PT) and young sire program (YS) were compared with breeding program using genomic selection (GS) taking parameters derived from Chinese Holstein breeding system. The results showed that, GS shortened generation interval by 1.5-2.2 years, and increased the genetic progress by 30-50%, comparing to PT and YS, respectively. Economic analysis showed that GS could obtain a higher breeding efficiency, being 119 and 97% higher than that of PT and YS, respectively; and GS was also powerful in improving functional traits with a low heritability. Main factors affecting breeding efficiency in GS were further discussed, including selection intensity, accuracy and the cost of SNP genotyping. Our finding provided references for future designing and implementing GS in Chinese dairy population.