Soybean is a widely planted genetically modified crop around the world. However, it is still one of the most recalcitrant crops for genetic transformation due to the difficulty of regeneration via organogenesis and some factors that affect the transformation efficiency. The percentages of resistant bud formation and transient expression efficiency are important indexes reflecting the regeneration and transformation efficiency of soybean. In this study, the percentages of resistant bud formation and transient expression of β-glucuronidase (GUS) were compared after treatment with sonication or surfactant and co-treatment with both. The results showed that treatment with either sonication or surfactant increased the percentage of resistant bud formation and transient expression efficiency. The highest percentages were acquired and significantly improved when cotyledon node explants were co-treated with sonication for 2 s and surfactant at 0.02% (v:v) using two different soybean genotypes, Jack and Zhonghuang 10. The improved transformation efficiency of this combination was also evaluated by development of herbicide-tolerant soybeans with transformation efficiency at 2.5–5.7% for different genotypes, which was significantly higher than traditional cotyledonary node method in this study. These results suggested that co-treatment with surfactant and sonication significantly improved the percentages of resistance bud formation, transient expression efficiency and stable transformation efficiency in soybean.

The presence of pesticide residues in pears is a serious health concern. This study presents the results from a 2-year investigation (2013–2014) that used gas chromatography, GS/MS and UPLC/MS-MS to measure the levels of 104 pesticides in 310 pear samples. In 93.2% of the samples, 43 pesticides were detected, of which the maximum residue levels (MRLs) were exceeded in 2.6% of the samples. Multiple residues (two to eight compounds) were present in 69.7% of the samples; one sample contained nine pesticides and one sample contained 10. Only 6.8% of the samples did not contain residues. To assess the health risks, the pesticide residue data have been combined with daily pear consumption data for children and adult populations. A deterministic model was used to assess the chronic and acute exposures based on the Joint Meeting on Pesticide Residues (JMPR) method. A potential acute risk was demonstrated for children in the case of bifenthrin, which was found to be present at 105.36% of the acute reference dose (ARfD) value. The longterm exposure of the Chinese consumer to pesticide residues through the consumption of raw pears was far below the acceptable daily intake (ADI) criterion. Additionally, the matrix ranking scheme was used to classify risk subgroups of pesticides and pear samples. In general, 95.5% of samples were deemed to be safe and nine pesticides were classified as being of a relatively high risk. The findings indicated that the occurrence of pesticide residues in pears should not be considered a serious public health problem. Nevertheless, a more detailed study is required for vulnerable consumer groups, especially children. Continuous monitoring of pesticides in pears and tighter regulation of pesticide residue standards are recommended.

Soybean seed storage protein is one of the most important plant vegetable proteins, and β subunit is of great significance to enhance soybean protein quality and processing property. F2 segregated population and residual heterozygous lines (RHL) derived from the cross between Yangyandou (low level of β subunit) and Zhonghuang 13 (normal level of β subunit) were used for mapping of β subunit content. Our results showed that β subunit content was controlled by a single dominant locus, qBSC-1 (β subunit content), which was mapped to a region of 11.9 cM on chromosome 20 in F2 population of 85 individuals. This region was narrowed down to 2.5 cM between BARCSOYSSR_20_0997 and BARCSOYSSR_20_0910 in RHL with a larger population size of 246 individuals. There were 48 predicted genes within qBSC-1 region based on the reference genome (Glyma 1.0, Williams 82), including the two copies of β subunit coding gene CG4. An InDel marker developed from a thymine (TT) insertion in one copy of CG4 promoter region in Yangyandou cosegregrated with BARCSOYSSR_20_0975 within qBSC-1 region, suggesting that this InDel marker maybe useful for marker-assisted selection (MAS).