鄂西咸丰地区土壤元素地球化学分布及其影响因素

本研究以鄂西咸丰县土壤为研究对象，统计了区内表层土壤中30种元素指标的地球化学背景值，再结合因子分析方法，探讨了地球化学背景值的成因机制，分析了土壤元素空间分布及其影响因素。结果表明，咸丰地区土壤B、Cd、Cr、F、Hg、Se元素的含量明显高于全国和湖北省背景值，I、Mo、Sr、Ca O、Na₂O等元素较全国贫乏。因子分析结果表明成土母质、工矿活动、腐殖质过程、风化作用、地形因素以及人类的生产活动共同影响着研究区内表层土壤的背景值特征，其中成土母质决定了土壤中化学元素的分布特征，但是工矿活动、地形特征和人类活动等过程重塑了区域元素分布特征。     

兽药检测实验室人员技术档案管理的思考

兽药检测实验室的兽药检测是把控兽药质量的关键环节。技术档案是对技术人员的专业、技术职称、工作经历和资质认证等信息的详细记录，能够集中反映其综合素质，可为兽药检测工作的高效开展提供信息资源。在新时代高质量发展的背景下，兽药检测实验室人员技术档案管理工作正逐步推进，但在技术档案管理认知、管理制度、服务性功能等方面仍存不足。本文从开发技术档案服务功能的层面出发，从提高对技术档案的重视程度入手，围绕档案管理制度的建立等方面提出建议，以期提高技术档案管理水平，促进兽药检测工作的高质量发展。     

重庆市丘陵山区农业机械化发展实践

发展丘陵山区农业机械化要根据丘陵山区的特点，遵循内在经济规律。阐述了丘陵山区农业机械化发展的核心制约因素、依靠，总结了重庆市丘陵山区农业机械化发展的思路、主要举措以及经验，为我国丘陵山区的农机化发展提供参考和借鉴。      

补喂鞣花酸对哺乳期马驹寄生虫感染情况的影响

【目的】研究补喂鞣花酸对哺乳期纯血马马驹肠道寄生虫感染情况的影响，揭示鞣花酸在马属动物消化道寄生虫防治方面的作用，为新型驱虫药物的筛选提供参考依据。【方法】选择平均体重（143.33±16.10） kg、出生日期（±5 d）、寄生虫感染率相近的哺乳期纯血马马驹15匹，随机分为对照组、试验Ⅰ和Ⅱ组，每组5匹。在相同的饲养条件下，对照组马驹不做任何处理，试验Ⅰ组马驹每天补喂15 mg/kg BW鞣花酸，试验Ⅱ组补喂30 mg/kg BW鞣花酸，试验期60 d，分别在试验的第0、15、30、45、60天采集马驹粪便样品，检测各组虫卵种类，统计虫卵数量，并评价驱虫效果。【结果】哺乳纯血马驹感染率高的寄生虫有10种，其中感染率最高的寄生虫是马副蛔虫、马圆线虫及细颈三齿线虫。随着鞣花酸补喂时间的延长及剂量的增加，寄生虫的感染率呈降低趋势，细颈三齿线虫卵、马圆线虫卵、马副蛔虫卵和韦氏类圆线虫卵的排出量显著降低（P<0.05）。补喂鞣花酸后第60天试验Ⅰ和Ⅱ组虫卵总数比对照组分别降低66.59%和97.06%；试验Ⅰ组第30和60天虫卵减少率分别为30.10%和42.97%；试验Ⅱ组第30和60天虫卵减少率分别为37.51%和49.86%。【结论】在本试验条件下，给哺乳马驹补喂鞣花酸能够显著降低寄生虫的感染及粪便中细颈三齿线虫卵、马圆线虫卵、马副蛔虫卵和韦氏类圆线虫卵的排出量，且补喂剂量为30 mg/kg BW效果更佳。     

‘库尔勒香梨’幼果内源激素分布差异与果实萼片脱落的关系

以‘库尔勒香梨’‘鸭梨’‘锦丰梨’为试验材料,探究‘库尔勒香梨’幼果不同部位内源激素分布差异与果实萼片脱落之间的关系。采用酶联免疫吸附测定法(ELISA)测定幼果萼端、中部和下部的IAA、ZR、GA3和ABA质量分数,进行差异显著性分析。结果表明,‘库尔勒香梨’脱萼幼果、‘鸭梨’幼果与‘库尔勒香梨’宿萼幼果、‘锦丰梨’幼果萼端IAA、ZR质量分数不存在差异性,而幼果下部IAA和ZR质量分数存在极显著性差异,‘库尔勒香梨’脱萼幼果和宿萼幼果下部ABA和GA3质量分数存在极显著性差异。‘库尔勒香梨’脱萼幼果和‘鸭梨’幼果中的IAA、GA3主要分布在萼端,ZR主要分布在中部,ABA主要分布在萼端和下部;宿萼幼果和‘锦丰梨’幼果中的IAA、ZR和GA3主要分布在幼果中部,ABA主要分布在幼果下部。在‘库尔勒香梨’萼片脱落临界期,脱宿萼幼果不同部位内源激素质量分数存在显著差异性,幼果下部IAA、ZR质量分数高有利于萼片宿存,幼萼片端GA3和ABA质量分数高可能有利于萼片脱落。     

北方后墙体塑料大棚绿色采暖智能控制方案

本文针对北方后墙体塑料大棚冬季绿色采暖，提出一种解决方案。该系统是典型的“互联网+”设施农业智能控制系统，其网络架构由底层传感网络层、中层汇聚层和顶层服务应用层构成，可实现远程监控。该系统白天利用阳光集热器将空气加热并通过管道循环泵将热空气输送到地下，利用热交换原理使得土壤升温蓄能，夜间缓慢释放热能来解决北方后墙体塑料大棚冬季采暖的问题。当发生连续阴天、倒春寒等情况时，可启动电地热辅助装置来维持棚内的温度。该方案与北方现有温室大棚智能系统相比，具有绿色环保，节能降耗等特点。     

沙门氏菌分析检测方法研究进展

沙门氏菌是一种常见的食源性致病菌,可引发多种人畜共患病.在世界各国的细菌性食物中毒事件中,沙门氏菌造成的中毒病例常居首位,严重威胁着人畜的生命健康.对食品中的沙门氏菌进行准确、快速的分析检测可预防该致病菌引发的食源性疾病,对于保障人畜的饮食安全具有重要意义.综述了检测沙门氏菌的几种典型分析方法及其优缺点,并对沙门氏菌检测技术的发展进行了展望.     

现阶段兽医实验室人员管理的对策思考

兽医实验室是做好动物防疫工作的重要机构，是兽医行政管理、执法监督的重要技术保障，在动物疫病预警预报和保障动物源性食品安全方面具有重大意义。本文认为当前兽医实验室在人员管理制度、人员能力和人员安全意识等方面存在发展不足，并结合问题提出了建立健全兽医实验室管理制度，明确岗位与人员配备，加强安全宣传教育，强化人员业务培训，加强人员监督与考核落实等发展建议，以期为做好新时期兽医实验室管理提供参考。     

基于土地利用和景观格局的高原山区湖库水质变化主要贡献因子分析

[目的] 准确分析与识别高原山区湖库水质变化的主要贡献因子，为高原山区乃至全国水环境污染防治和管理工作提供科学参考。 [方法] 解译贵阳市“两湖一库”流域2013，2016和2019年3期土地利用数据，采集丰-枯水期总氮和总磷水质数据，通过Pearson相关分析揭示3期土地利用/景观指数与水质的相关性，冗余分析识别土地利用/景观指数对水质的贡献。 [结果] ①2013-2019年，林地、建设用地和草地分别增加11.72%，9.96%和3.18%，水田、旱地分别减少8.77%，12.07%。林地与建设用地均表现为结合度增强，斑块数量比例增加。 ②红枫湖水质达到国家Ⅰ-Ⅲ类水质标准，百花湖和阿哈水库的总磷、总氮浓度波动较大，水质状况劣于红枫湖。 ③林地面积比例和景观指数与水质指标整体表现为负相关，建设用地面积比例和景观指数与水质指标整体表现为正相关。 ④2013和2016年林地斑块数量比例的贡献度分别达到54.0%和52.5%，2019年建设用地面积比例的贡献度达到68.7%。 [结论] 林地表现出“汇”的效果，建设用地则是“源”的效果，增加流域“汇”效应，抑制污染“源”的输出，是缓解“两湖一库”流域水质恶化的有效手段。     

Efficient exploration and SSR identification of autotetraploids from the seedlings of thirteen apomictic Citrus genotypes北大核心CSCD

【Objective】Citrus is a crucial part of Chinese fruit crops. There are abundant citrus germplasm resources in China, but many excellent local varieties are gradually eliminated by the market due to the problem of numerous seeds within the fruit. The fruits of triploid plants are generally seedless because of their sterile male and female gametes. Therefore, triploid production is a promising strategy to breed seedless cultivars in citrus. Triploids can be obtained by interploidy crossing between diploids and tetraploids. However, the tetraploid germplasm is rare, which limits the application of this strategy. Exploration of tetraploids is an important prerequisite for triploid production with the aim to improve the seedy local cultivars in our country. For the rootstock improvement, tetraploid plants are also valuable resources because of their higher metabolite content, and better resistance than their diploid parents. In this study, we planned to explore tetraploid plants from 13 local cultivars in our country by using the traits of spontaneous doubling of the nucellar cells in polyembryonic citrus varieties. The exploration of tetraploids from the above 13 local cultivars will not only provide excellent tetraploid parents for the production of triploid plants, but also lay the foundation for the basic research about the effect of genome duplication on some important trait change, such as dwarfing, extensive adaptivity and higher medicinal value in tetraploids.【Methods】After the mature fruits were harvested, the seeds were extracted and the seed coats were peeled off, and then they were placed in a thermostat to accelerate germination. When the seeds germinated, they were sown in pots and cultivated in a plant growth chamber. After the seedlings grew up with three or more leaves, putative polyploids were screened according to the morphological feature showing lower height, shorter taproots, less lateral roots, thicker and rounder leaves and declined oil gland density. The ploidy levels of these putative polyploids were further confirmed by flow cytometric analysis and the observation on root tip chromosome numbers. After determination of the ploidy level, some morphological traits, including plant height, root length and diameter, lateral root number, stem diameter, leaf thickness and shape index of the tetraploids and their corresponding diploid parents were measured at the same developmental stage. SSR analysis was used to identify the genetic origin of the explored tetraploids with at least three pairs of SSR primers selected for each cultivar.【Results】The polyembryonic degree of seeds from each cultivar was firstly determined and it showed that the seeds of all 13 cultivars were polyembryonic. Among them, Qu tangerine had the highest number of embryos with an average of 9.4 embryos per seed and Bingtang sweet orange had the lowest number of embryos with an average of 2.2 embryos per seed. Based on the morphological trait screening, we identified 2, 1, 3, 2, 7, 3, 1, 3, 1, 3, 17, 1 and 2 putative polyploids respectively from 343, 499, 892, 385, 519, 290, 457, 241, 119, 690, 828, 114 and 129 seedlings of Qianshanhong tangerine, Bayue tangerine, Qu tangerine, Zao tangerine, Bianping tangerine, Ougan tangerine, Shitougan, Bingtang sweet orange, Jinmi sweet orange, Moping Xiangcheng, Japanese Xiangcheng, Zhique and Youpi kumquat. After further confirmation of ploidy levels concerning above putative tetraploids, we obtained 45 tetraploids and one hexaploid plant from Qu tangerine, with an average occurrence rate of 0.85%, among which the rate of Japanese xiangcheng was the highest with 2.05% and the rate of Bayue tangerine was the lowest with 0.20%. The exploration time from seed germination to obtaining tetraploid seedlings varied among cultivars, with the longest time (42 days) used in Youpi kumquat and the shortest time (23 days) in Shitougan. The morphological traits of tetraploids and their corresponding diploid seedlings from nine cultivars of Qianshanhong tangerine, Qu tangerine, Zao tangerine, Bianping tangerine, Ougan tangerine, Bingtang sweet orange, Moping Xiangcheng, Japanese Xiangcheng and Youpi kumquat were measured. For plant height, tap root length, lateral root numbers and leaf thickness, the tetraploid seedlings of seven cultivars showed significant differences with their diploid parents. For taproot and stem diameter, only the tetraploid seedlings explored from Bingtang sweet orange and Japanese Xiangcheng had significant difference with their diploid parents. For leaf shape index, the tetraploid seedings from Bianping tangerine and Moping Xiangcheng exhibited significant differences with their diploid seedlings. In conclusion, most tetraploid seedlings of all nine cultivars showed lower plant height, shorter and thicker taproot, less lateral root number, thicker and rounder leaves than those of their diploid parents. These results provide supports for the screening of putative tetraploids based on morphological trait observation. For analyzing the genetic origin of the tetraploids obtained in this study, at least three SSR markers were used in each genotype. The results showed that the bands of all 45 tetraploids were identical with those of their corresponding diploids, indicating that all the 45 tetraploids might originate from the spontaneous chromosome doubling of nucellar cells of their corresponding diploids. In addition, the bands of the hexaploid from Qu tangerine were also identical with their diploid parent. We speculated that it might derive from chromosome doubling of a triploid zygotic cell, which formed by selfing of a FDR-type 2n gamete with a normal n gamete, and both gametes were produced by Qu tangerine.【Conclusion】This study verified that morphological screening combined with flow cytometry ploidy determination and SSR analysis is an efficient approach to exploring polyploid seedlings from apomictic citrus. Using this method, 45 autotetraploid and one hexaploid plants were obtained from 13 apomictic citrus genotypes. These newly discovered tetraploids are potentially valuable for not only genetic improvement of some elite local citrus cultivars with seeds produced by triploids using interploidy hybridization, but also selection of the promising rootstocks with dwarf, multi-resistance and broad adaptability characteristics to improve the ability to resist various abiotic and biotic stresses. © 2023 Journal of Fruit Science. All rights reserved.