BACKGROUND/OBJECTIVES:This paper aims to compare children's thyroid volume (Tvol) by age and gender in Zhejiang province in order to explore the factors influencing Tvol in this area.SUBJECTS/METHODS:This survey was a cross-sectional survey of a provincial representative sample of Zhejiang province children aged 6–12 years. The children were asked to provide a urine sample for the determination of urinary iodine concentration (UIC) and thyroid ultrasonography was performed for the determination of Tvol.RESULTS:The median (25th, 75th percentile) of UIC in children aged 6–12 years in Zhejiang province was found to be 170.0(111.2, 244.4) μg/l. The median (25th, 75th percentile) of Tvols was found to be 3.1(2.3, 4.2) ml. There were significant differences among the different age groups on BSA (Z=−17.911, P=0.000) and Tvol (Z=−1.996, P=0.046) but not on UIC and body mass index (P>0.05). Tvol was in significant association with BSA (P=0.000) but was not associated with UIC (P>0.05). Age, gender and BSA were significant in multiple linear regression (P<0.05).CONCLUSIONS:The median UIC of children aged 6–12 years falls in the optimal iodine status as recommended by WHO/UNICEF/ICCIDD. However, urinary iodine nutritional status had little effect on the Tvol in children aged 6–12 years in Zhejiang province. Age, gender and BSA were the influencing factors of Tvol.

Most crops are sensitive to salt stress, but their degree of susceptibility varies among species and cultivars. In order to understand the salt stress adaptability of Brassica napus to salt stress, we collected the phenotypic data of 505 B. napus accessions at the germination stage under 150 or 215 mM sodium chloride (NaCl) and at the seedling stage under 215 mM NaCl. Genome-wide association studies (GWAS) of 16 salt tolerance coefficients (STCs) were applied to investigate the genetic basis of salt stress tolerance of B. napus. In this study, we mapped 31 salts stress-related QTLs and identified 177 and 228 candidate genes related to salt stress tolerance were detected at germination and seedling stages, respectively. Overexpression of two candidate genes, BnCKX5 and BnERF3 overexpression, were found to increase the sensitivity to salt and mannitol stresses at the germination stage. This study demonstrated that it is a feasible method to dissect the genetic basis of salt stress tolerance at germination and seedling stages in B. napus by GWAS, which provides valuable loci for improving the salt stress tolerance of B. napus. Moreover, these candidate genes are rich genetic resources for the following exploration of molecular mechanisms in adaptation to salt stress in B. napus.

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Most plants are sensitive to salt-alkali stress, and the degree of tolerance to salt-alkali stress varies from different species and varieties. In order to explore the salt-alkali stress adaptability of Brassica napus, we collected the phenotypic data of 505 B. napus accessions at seedling and mature stages under control, low and high salt-alkali soil stress conditions in Inner Mongolia of China. Six resistant and 5 sensitive materials, respectively, have been identified both in Inner Mongolia and Xinjiang Uygur Autonomous Region of China. Genome-wide association studies (GWAS) for 15 absolute values and 10 tolerance coefficients (TCs) of growth and agronomic traits were applied to investigate the genetic basis of salt-alkali tolerance of B. napus. We finally mapped 9 significant QTLs related to salt-alkali stress response and predicted 20 candidate genes related to salt-alkali stress tolerance. Some important candidate genes, including BnABA4, BnBBX14, BnVTI12, BnPYL8, and BnCRR1, were identified by combining sequence variation annotation and expression differences. The identified valuable loci and germplasms could be useful for breeding salt-alkali-tolerant B.napus varieties. This study laid a foundation for understanding molecular mechanism of salt-alkali stress adaptation and provides rich genetic resources for the large-scale production of B. napus on salt-alkali land in the future.

The aim of the present study was to explore the influencing factors of urinary iodine concentration (UIC) and the relationship between iodised salt concentration and UIC in order to give suggestions for the surveillance of iodine nutrition status. For this purpose, a multi-stage cluster sampling technique was employed in the present cross-sectional study. Correlations between UIC and salt iodine concentration were evaluated by Spearmen's correlation analysis. Risk factors of having a lower UIC were identified by logistic regression analysis, and the equations of UIC and salt iodine concentration were fitted by curve regression analysis. The median UIC was found to be 162·0 (25th -75th percentile 98·2-248·6) mg/l. The UIC was correlated with salt iodine concentration (Spearman's r ¼ 0·144, P,0·05). The multiple logistic regression analysis found the following influencing factors for having a lower UIC: age (OR 0·98, 95 % CI 0·98, 0·98, P,0·05); sex (OR 0·81, 95 % CI 0·71, 0·92, P, 0·05); education level (OR 0·87, 95 % CI 0·83, 0·90, P, 0·05); status of occupation (OR 0·91, 95 % CI 0·86, 0·96, P,0·05); occupation (OR 1·03, 95 % CI 1·00, 1·05, P,0·05); pickled food (OR 1·24, 95 % CI 1·08, 1·42, P, 0·05); salt iodine concentration (OR 1·03, 95 % CI 1·02, 1·03, P, 0·05). The curve regression analysis found that UIC (y) and salt iodine concentration (x) could be expressed by the following equation: y ¼ 1·5772x 1·4845 . In conclusion, the median UIC of individuals in Zhejiang Province falls within optimal status as recommended by the WHO/UNICEF/International Council for Control of IDD. To maintain optimal iodine nutrition status, salt iodine concentration should be in the range of 16·4 to 34·3 mg/kg.