基于逻辑回归的植物新品种权质量评估研究——以杂交水稻品种权为例

随着植物新品种权的申请授权量急剧增长,品种权的"数量多、质量差"的问题引起了全社会的普遍关注。如何评价品种权质量成为重要的理论和现实问题。为了科学合理地判断我国品种权的综合质量水平,首先从竞争力的角度界定植物新品种权质量的定义,然后从品种权的法律、技术和经济三大属性建立品种权质量评价指标体系,并利用均值差异法验证品种权质量指标的有效性,最后采用逻辑回归模型构建品种权质量综合指数,以便全面、快捷地综合评价品种权质量。植物新品种权质量评估研究不仅有利于解决品种权质量判断标准问题,对提高品种权质量水平提供了理论依据,而且为我国品种权的价值评估、许可转让、融资、抵押等交易活动提供重要参考。     

Effects of different dl‐selenomethionine and sodium selenite levels on growth performance,immune functions and serum thyroid hormones concentrations in broilers

This trial was conducted in a 2 × 3 + 1 factorial arrangement based on a completely randomized design to evaluate the effects of different dl ‐selenomethionine (dl ‐Se‐Met) and sodium selenite (SS) levels on growth performance, immune functions and serum thyroid hormones concentrations in broilers. A total of 840 Ross 308 broilers (7 days old) were allocated by body weight to seven treatments (three replicates of 40 birds each treatment) including (1) basal diet (containing 0.04 mg of selenium (Se)/kg; control) without supplementary Se; (2, 3 and 4) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as SS; (5, 6 and 7) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as dl ‐Se‐Met. The experiment lasted 42 days. The results revealed that dietary Se supplementation improved (p < 0.05) average daily gain, feed efficiency, immune organ index, serum immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM) and triiodothyronine (T₃) concentrations and decreased (p < 0.01) thyroxine (T₄)/T₃ ratio in serum compared with the control. Broilers receiving the dl ‐Se‐Met‐supplemented diets had higher (p < 0.05) feed efficiency, thymus index, the amounts of IgA, IgG, IgM and T₃ as well as lower (p < 0.05) serum T₄ concentrations and T₄/T₃ ratio than those consuming the SS‐supplemented diets. Serum IgA and IgM levels of broilers fed 0.15 mg Se/kg were significantly higher (p < 0.05) than those of broilers fed 0.05 or 0.25 mg Se/kg. In summary, we concluded that dl ‐Se‐Met is more effective than SS in increasing immunity and promoting conversion of T₄ to T₃, thus providing an effective way to improve the growth performance of broilers. Besides, based on a consideration of all experiment indices, 0.15 mg Se/kg was suggested to be the optimal level of Se supplementation under the conditions of this study.     

葫芦砧木低温处理鉴定方法研究

对2个具有低温抗性差异的葫芦砧木A12、A05及西瓜TRM进行低温处理,试验结果表明,葫芦幼苗(0.43~0.71)的低温抗性显著高于西瓜(1.0),4℃条件下A12的耐低温性高于A05,6℃条件下相反;3叶期2个砧木间冷害指数差异显著,且叶绿素含量变化均达极显著,叶绿素含量变化程度与冷害指数具有显著正相关(R2=0.65),因此,叶绿素含量可以作为耐低温葫芦砧木材料选择的一个标准,且3叶1心期6℃为相对较好的低温处理条件。     

Assessment of the hip reduction angle for predicting osteoarthritis of the hip in the Labrador Retriever

Hip palpation has been used to provide semiquantitative information regarding passive joint laxity and susceptibility to hip dysplasia. The purpose of this study was to: (1) evaluate the intra- and inter-examiner repeatability of the hip reduction angle measured at 4 months of age by three examiners using manual goniometry and an electromagnetic tracking system; (2) compare the hip reduction angle measured with manual goniometry to the hip reduction angle measured with the electromagnetic tracking system; and (3) evaluate the hip reduction angle, distraction index and Ortolani manoeuvre at 4 months of age as predictors of the development of hip osteoarthritis at 12 months of age in 11 Labrador Retriever dogs. Intra- and inter-examiner repeatability was demonstrated for both the manual and electromagnetic goniometric measurement of the hip reduction angle (coefficient of variation < 4.3% and < 6.1%; and P = 0.163 and P = 0.836 respectively). The hip reduction angle measured by manual goniometry was moderately correlated to the hip reduction angle measured by the electromagnetic tracking system (r = 0.603, P < 0.0000). The hip reduction angle measured by manual and electromagnetic goniometry was a poor predictor of osteoarthritis at 12 months of age (r = 0.231, P < 0.062, and r = 0.321, P < 0.01). The distraction index was moderately correlated with the development of osteoarthritis by 12 months of age (r = 0.493, P < 0.0000). The Ortolani sign was sensitive (100%) but not specific (41%) for the development of osteoarthritis at 12 months of age. The hip reduction angle did not further quantify the Ortolani manoeuvre as a predictor of osteoarthritis in Labrador Retrievers.     

欧盟、美国和日本加工农产品中农药残留评估现状

本文介绍了欧盟、美国和日本评估加工农产品中农药残留的数据要求和试验准则,以及开展膳食摄入风险评估和推荐农药最大残留限量(MRL)的方法,汇总了用于农药残留评估的加工农产品及其分类,分析了加工农产品中农药MRL制定现状,为进一步提高我国相关领域技术提供借鉴。比较分析结果表明,欧盟和美国在农药登记资料要求中明确提出了加工试验数据要求并且制定了相应的试验准则,美国在试验准则中描述了加工农产品中农药MRL的推荐原则;美国和日本制定了一定数量的加工农产品中农药MRL,欧盟建立了适用于监管农药MRL的加工因子数据库;欧盟、美国和日本均在相关法规中规定了加工农产品中农药残留的合规性判定。     

Natural hybridization between wheat (Triticum aestivum L.) and its wild relatives Aegilops geniculata Roth and Aegilops triuncialis L.

BACKGROUND

Cultivated bread wheat (Triticum aestivum L.) spontaneously hybridizes with wild/weedy related Aegilops populations, but little is known about the actual rates at which this hybridization occurs under field conditions. It is very important to provide reliable empirical data on this phenomenon in order to assess the potential crop–wild introgression, especially in the context of conducting risk assessments for the commercialization of genetically modified (GM) wheat, as gene flow from wheat to Aegilops species could transfer into the wild species genes coding for traits such as resistance to herbicides, insects, diseases or environmental stresses.

RESULTS

The spontaneous hybridization rates between wheat and A. geniculata and A. triuncialis, which are very abundant in the Mediterranean area, have been estimated for the first time in the northern part of the Meseta Central, the great central plateau which includes the largest area of wheat cultivation in Spain. Hybridization rates averaged 0.12% and 0.008% for A. geniculata and A. triuncialis, respectively. Hybrids were found in 26% of A. geniculata and 5% of A. triuncialis populations, at rates that can be ≤3.6% for A. geniculata and 0.24% for A. triuncialis.

CONCLUSION

The detection of Aegilops spp.–wheat hybrids in Aegilops populations indicates that gene flow can occur, although wheat is considered a crop with a low-to-medium risk for transgene escape. These data on field hybridization rates are essential for GM wheat risk assessment purposes. © 2023 Society of Chemical Industry.     

Proportionality principle revisited – relationship between application rates and pesticide residue concentrations in food commodities

BACKGROUND

The proportionality principle has been broadly used for over 10 years in regulatory assessments of pesticide residues. It allows extrapolation of supervised field trial data conducted at lower or higher application rates compared to the use pattern under evaluation by adjustment of measured concentrations, assuming direct proportionality between the rates applied and the resulting residues. This work revisits the principle idea by using supervised residue trials sets conducted under identical conditions but with deviating application rates. Four different statistical methods were used to investigate the relationship between application rates and residue concentrations and to draw conclusions on the statistical significance of the direct proportionality assumed.

RESULTS

Based on over 5000 individual trial results, the assumption of direct proportionality was not confirmed to be statistically significant (P > 0.05) using three models: direct comparison of application rates and residue concentrations ratios and two linear log-log regression models correlating application rate and residue concentration or only residue concentrations per se. In addition, a fourth model analysed deviations between expected concentrations following direct proportional adjustment and measured residue values from corresponding field trials. In 56% of all cases, the deviation was larger than ±25%, which represents the tolerance usually accepted for the selection of supervised field trials in regulatory assessments.

CONCLUSION

Overall, the assumption of direct proportionality between application rates and resulting residue concentrations of pesticides was not statistically significant. Although the proportionality approach is highly pragmatic in regulatory practice, its use should be considered carefully on a case-by-case basis. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.