Genetic Dissection of Major Rice QTLs for Strong Culms and Fine Mapping of qWS5 for Breeding Application in Transplanted System.

BACKGROUND: Rice is one of the major staples that feeds about one half of the global populations, and it is important to identify the genetic loci for the traits related to yield improvement. Lodging will cause severe yield loss when it happens, and stem diameter has been characterized as an important trait for lodging resistance. However, most QTLs for stem diameter have not been finely dissected due to their sensitivity to environmental fluctuation. RESULT: In this study, we performed QTL analysis for stem diameter using populations derived from Nipponbare (NIP) and strong culm variety YYP1, and confirmed the single and combined effect of three major QTLs by recombinant inbred lines (RILs). Based on the QTL location, we found that qWS5 is a novel QTL not well characterized before. To finely dissect the novel locus, several recombinant heterogeneous inbred families (HIFs) were selected from the RILs for linkage analysis and their derived nearly isogenic lines (NILs) were subjected to detailed trait investigation throughout different years. The HIF-NILs strategy confined the QTL to about 380 kb region supported by repeated genotype and phenotype data, and it lays the foundation for QTL cloning in the future. In addition, introgression of the QTL to an elite japonica variety SD785 was performed by successive backcrossing, and it confirmed the value of qWS5 in increasing stem diameter and other agronomic traits during rice breeding. CONCLUSIONS: We prove that qWS5 is a novel QTL with relatively stable effect for stem diameter and the QTL can be finely mapped to small region by the HIF-NILs strategy. The result will facilitate the improvement of rice lodging resistance by molecular marker assisted selection breeding.

Revelation of rice molecular design breeding: the blend of tradition and modernity.

As one of the major staple crops, rice feeds more than one half of the world population. Due to increasing population and dramatic climate change, the rice varieties with higher yield performance and excellent overall agronomic performance should be developed. The raise of molecular design breeding concept provides opportunity to get new breakthrough for variety development, and it is important to clarify the efficient gene combination during actual breeding. In this review, we summarize the recent advances about rice variety improvement either by marker assisted selection (MAS) breeding or popular gene editing technique, which will be beneficial to understand different aspects of the molecular design breeding. We provide genetic views for the classical MAS application, including the genetic effect of key genes and their combinations, the recurrent genome recovery rate at different backcross generations, linkage drag and recombination selection. Moreover, we compare the breeding value of recently-developed molecular techniques, including the advantage of high-throughput genotyping and the way and effect of gene editing in creating useful traits. Considering the current status and actual demands of rice breeding, we raise the strategy to take advantages of both traditional breeding resources and popular molecular techniques, which might pave the way to optimize the process of molecular design breeding in future.

Systematic impact of institutional pressures on safety climate in the construction industry.

This paper explores how three types of institutional pressure (i.e., coercive, mimetic and normative pressures) systematically impact on the safety climate of construction projects. These impacts are empirically tested by survey data collected from 186 questionnaires of construction companies operating in Shanghai, China. The results, obtained by partial least squares analysis, show that organizational management commitment to safety and employee involvement is positively related to all three institutional pressures, while the perception of responsibility for safety and health is significantly influenced by coercive and mimetic pressure. However, coercive and normative pressures have no significant effect on the applicability of safety rules and work practices, revealing the importance of external organizational pressures in improving project safety climate from a systematic view. The findings also provide insights into the use of institutional forces to facilitate the improvement of safety climate in the construction industry.

Cardiovascular health status in Chinese adults in urban areas: analysis of the Chinese Health Examination Database 2010.

BACKGROUND: The American Heart Association (AHA) recently developed definitions of cardiovascular health for adults and children based on 7 cardiovascular disease risk factors or health behaviors. We applied this new construct to examine the cardiovascular health status in adult Chinese urban residents. METHODS: Data of 1,012,418 subjects aged 20-65 years (55% were men; mean age, 42.4 years) who received health examination at 58 health examination centers across China was analyzed. The AHA ideal health behaviors index and ideal health factor index were evaluated among the subjects. RESULTS: Only 0.6% of male and 2.6% of female subjects met all 7 health components, and only 39.1% of the subjects met 5 or more components of ideal cardiovascular health. The prevalence of "ideal", "intermediate" and "poor" cardiovascular health was 1.5%, 33.9% and 64.6%, respectively. CONCLUSION: About two-thirds of the adult Chinese urban population has "poor" cardiovascular health. Comprehensive individual and population-based interventions must be developed to improve cardiovascular health status in China.