Development and identification of glyphosate-tolerant transgenic soybean via direct selection with glyphosate

Glyphosate-tolerant soybean is the most widely planted genetically modified crop worldwide. However, soybean remains recalcitrant to routine transformation because of the low infection efficiency of Agrobacterium to soybean and lack of useful selectable markers. In this study, several Agrobacterium strains and cell densities were compared by transient expression of the GUS gene. The results showed that Agrobacterium strain Ag10 at cell densities of OD_(600) of 0.6–0.9 yielded the highest infection efficiency in Agrobacterium-mediated soybean cotyledonary node transformation system. Meanwhile, a simple and rapid method was developed for identification of glyphosate tolerance in putative T_0 transgenic plants, consisting of spotting plantlets with 1 μL Roundup~?. The whole cycle of genetic transformation could be shortened to about 3 mon by highly efficient selection with glyphosate during the transformation process and application of the spot assay in putative T_0 transgenic plantlets. The transformation frequency ranged from 2.9 to 5.6%. This study provides an improved protocol for development and identification of glyphosate-tolerant transgenic soybeans.     

小组参与式教学在水产动物营养与饲料学中的探索与实践

为提高学生在教学过程中的参与度,培养学生自主学习与相互协作的能力,提出了以小组为单位参与水产动物营养与饲料学课堂教学的详细方案,制定了相应的考核评价体系。教学实践证明,这一方法对于提高学生学习的主动性、积极性,培养学生独立思考、自主解决问题的能力及团队合作精神是确实有效的。分析了应用中存在的一些问题,并提出了进一步改进完善的措施。     

园林植物春季最佳观赏期调查研究

目前,由于缺乏准确的园林植物最佳观赏期的资料,导致优秀的规划设计方案难以落到实处,园林景点建成之后景观效果大打折扣。针对以上问题,作者采用实地调查观测的方法对园林植物春季最佳观赏期和最佳观赏顺序进行了研究。记录整理典型地点园林植物的最佳观赏期和最佳观赏顺序,为园林规划设计、植物配置和养护管理提供科学的参考依据。     

植物DNA甲基化研究进展

植物经常暴露在各种生物和非生物的胁迫之下,这些胁迫会影响植物的生长发育和繁殖并最终导致植物死亡。为了抵御不利的环境条件,植物已经进化出复杂而精细的网络来感知胁迫并激活防御系统。为此,植物激活许多信号转导通路,这些信号转导通路可以改变一些胁迫响应基因的表达,从而引起植物形态、生理和生化的改变以适应逆境。DNA胞嘧啶甲基化是高等真核生物的主要表观遗传机制之一,在维持基因组稳定性和调节基因表达方面起着关键作用。表观遗传变异比遗传变异更为灵活。一旦环境条件发生变化,为了适应新的环境植物都会发生表观遗传的改变。许多研究表明DNA甲基化参与植物的发育和应激反应。基于相关研究对DNA甲基化进行了综述,对植物逆境胁迫有重要意义。     

In Vitro Evaluation of the Effects of Selected Plants on the Growth of the Mycelial Form of Histoplasma capsulatum Variety farciminosum in Ethiopia

Epizootic lymphangitis is prevalent in equines in Ethiopia, causing remarkable economic and welfare impacts but often neglected. Lack of effective treatment contributed to its continued occurrence, and hence, search for an effective treatment should be considered a priority area to minimize its impacts. Previous ethnobotanical studies have reported that Curcuma longa, Phytolacca dodecandra, and Datura stramonium were used to treat cutaneous fungal infections and reduce their incidence. The treatment effects of these plants against epizootic lymphangitis should be studied. The in vitro growth inhibitory effects of methanol extracts of the root of C. longa, berry of P. dodecandra, and leaf of D. stramonium were evaluated. Histoplasma capsulatum var farciminosum was isolated from clinical cases of epizootic lymphangitis in carthorses in central Ethiopia. The nested polymerase chain reaction was used to confirm the identity of the isolates. Serial twofold dilutions of the extract of berries of P. dodecandra and leaves of D. stramonium were done in sterile water, whereas dilution of the extract of roots of C. longa was done in dimethylsulphoxide. The effects of the plants on the growth of Histoplasma capsulatum var farciminosum were assessed by agar dilution assay. Culture media with no antifungal agent and media containing ketoconazole served as negative and positive control, respectively. The methanol extract of C. longa showed inhibitory effects at concentrations ranging from 0.07 to 5 mg/mL. Similarly, the methanol extract of P. dodecandra showed growth inhibitory effects at concentrations ranging from 0.156 to 5 mg/mL. That is, the growth inhibitory concentration of C. longa was 0.07 mg/mL, whereas that of P. dodecandra was 0.156 mg/mL. In contrast, D. stramonium showed no inhibitory effect. This preliminary observation showed that methanol extracts of C. longa and P. dodecandra showed inhibitory effects on the growth of Histoplasma capsulatum var farciminosum requiring further repeated in vitro evaluation so as to generate adequate evidence, which would justify in vivo trials.     

林下姜科植物的选育与栽培技术研究综述

树木褐根病是由有害木层孔菌 (Phellinus noxius) 引起的一类土壤传染性根部病害，为了实施对 这类病害的生物防治，结合唯一氮源 1- 氨基环丙烷 -1- 羧酸（ACC）为底物和平板对峙法，从澳门松山市 政公园健康树木的根际分离得到 1 株对有害木层孔菌具有较强拮抗活性的菌株 1583。采用一对细菌通用 引物 PCR 扩增获得菌株 1583 的 16S rDNA 基因序列，其片段大小为 1 496 bp，系统进化树显示菌株 1583 与 Burkholderia seminalis 的亲缘关系最近，综合结果鉴定该菌株为伯克霍尔德菌（Burkholderia sp.）。拮抗 性研究表明，菌株 1583 对油菜菌核病病原菌（Sclerotinia sclerotiorum）、黑松叶斑病病原菌（Pestalotiopsis sp.）、香蕉枯萎病病原菌（Fusarium oxysporum f. sp. cubense）、白蝴蝶炭疽病病原菌（Colletotrichum sp.） 和美人蕉瘟病病原菌（Pyricularia cannaecola hashioka）等植物病原真菌均有明显的抑制作用。     

药用植物作为隔离剂对家蚕饲养的影响

为寻找一种环保且防病的隔离剂,采用云南省山区常见的药用植物,桉树叶、艾叶、松针作为隔离剂,与家蚕常用隔离剂焦糠作对照,考察家蚕食桑情况、蚕座吸湿能力、抗病毒能力、茧质成绩等因素对五龄期家蚕生长的影响。结果发现,供试粗型药用植物不影响家蚕食桑;随着家蚕生长到五龄后期,不同处理组的吸湿能力差异明显(P0.05),而同一处理组的吸湿变化不明显但与对照组差异显著(P0.05);家蚕核型多角体病毒感染7 d后艾叶组的存活率最高;全茧量、茧层率方面各药用植物与焦糠组无显著差异(P0.05)。上述结果表明供试药用植物对家蚕无毒副作用,艾叶可代替焦糠作为隔离剂的新措施,对防治家蚕病害、减少环境污染具有重要意义。     

水生动物肌醇营养研究进展

肌醇是大多数水生动物保持健康、促进生长发育必需的营养素,它在细胞膜磷脂合成、神经递质传递和肝脏脂质转运等方面发挥重要作用。饲料中肌醇缺乏导致水生动物生长不良、体表充血、鳍条糜烂、体色发黑、脂肪肝等症状。本文综述了肌醇的理化性质,肌醇在水生动物营养中营养生理作用、需要量及影响因素等,同时还介绍了肌醇的来源和测定方法,并展望了肌醇在水生动物营养中进一步的研究和应用方向。