模拟酸雨对小白菜生长过程中生理生化指标的影响

[目的]为科学减少和预防酸雨危害,提高小白菜产量提供理论依据。[方法]采用盆栽方法,研究了模拟酸雨对小白菜生长过程中叶绿素含量、过氧化物酶（POD）活性和游离脯氨酸含量几个生理生化指标的影响。[结果]随着酸雨浓度的增大,小白菜叶片出现可见性伤害,叶片黄化甚至死亡;叶绿素含量明显降低;POD活性及游离脯氨酸含量随着酸雨浓度的增加和时间的推移呈上升趋势。[结论]酸雨对小白菜具有一定的毒害作用,且随着酸雨处理浓度的增加和时间的推移对小白菜的毒害作用加深,伤害加大。     

银耳多糖对离体骨骼肌疲劳的影响

采用脉冲式电流刺激蟾蜍离体腓肠肌作为疲劳模型，研究银耳多糖对离体骨骼肌疲劳的影响。结果表明：较低浓度（0．05％、0．10％）的银耳粗多糖可以延长收缩幅度下降到最大收缩幅度90％、50％和10％的时间（P〈0．05）。较高浓度的银耳多糖（0．45g）可以缩短收缩幅度达到最大收缩幅度50％，10％的时间（P〈0．05）。适宜浓度的银耳粗多糖对离体骨骼肌的疲劳具有延缓作用。     

不同基因型菜心游离小孢子培养和植株再生

以11个不同基因型的菜心栽培品种为试材,研究不同培养条件对菜心游离小孢子胚诱导和植株再生的影响。结果有7个基因型材料获得小孢子胚,从不同基因型诱导形成胚的频率存在显著差异,表明基因型是影响菜心小孢子胚发生的主要因素;第1天热激培养时用170 g/L高浓度蔗糖培养之后转换成含130 g/L蔗糖培养基能显著提高小孢子胚诱导率;0.05 mg/L 6-BA+0.2 mg/L NAA能促进菜心小孢子诱导成胚;添加0.4 mg/L GA3可显著提高菜心小孢子胚芽诱导率和平均每胚出芽数。7个基因型材料均诱导出再生植株,植株诱导率为100%。     

Rare Finding of a Full Nuchal Ligament Lamellae With Attachment Points From C2–C7 in One Australian Stock Horse

For over 200 years, equine anatomic literature has chiefly portrayed the attachment points of the nuchal ligament lamellae (NLL) from the second to the seventh cervical vertebrae (C2–C7). However, recent studies have shown that the modern domestic horse, Equus caballus, primarily exhibits the attachments points from C2–C5. Here we present the rare finding of a complete NLL attached from C2–C7 in one Australian Stock Horse (ASH) and discuss the potential implications of these findings. Previously, this trait has only been confirmed among close descendants of Equus ferus ferus; namely the primitive Dutch Konik and Bosnian Mountain Horse. The examination of the NLL attachment points in 55 unrelated horses of mixed breeds revealed that 52 horses had attachments from C2–C5; 1 horse (Welsh Cob) had attachments from C2–C6; and only 2 horses (ASH and Dutch Konik) presented with a complete NLL attached from C2–C7. In light of earlier findings that suggest this loss of NLL attachment at C6 and C7 occurred after domestication, a possible explanation for this finding in 1 ASH is that it is a remnant trait from the founder population of Waler horses that contributed to the early development of the ASH breed. The reported rare occurrence of a complete NLL (C2–C7) in a modern domesticated equine (ASH) suggests that there may be other individuals expressing this unique trait, providing opportunity for its preservation.     

大白菜游离小孢子培养中胚胎发生及发育途径

[目的]观察大白菜离体小孢子培养中的胚胎发生及发育途径.[方法]以大白菜F1代杂交种为试材,采用光学显微镜观察游离小孢子胚胎发生和发育途径.[结果]细胞热激后膨大是胚状体诱导的关键因素.大白菜小孢子诱导成胚有3种途径,小孢子均等分裂途径、小孢子不均等分裂途径和小孢子直接萌发出胚途径.均等分裂途径是在连续的均等分裂以后形成原胚,原胚继续分裂形成球形胚、心形胚、鱼雷形胚和子叶形胚.不均等分裂途径形成的两个细胞中较大的细胞继续分裂最终形成有极性的胚状体.[结论]该研究结果为大白菜小孢子的高频率诱导提供细胞学依据.     

大白菜新品种‘豫新1号’

 摘要：采用游离小孢子培养双单倍体技术育成大白菜一代杂种‘豫新1号’。该品种生育期75 d；抗病毒病、霜霉病、黑斑病及黑腐病；净菜产量81.1—90.7 t/hm ；叶球矮桩叠抱，球形指数1.28，叶球绿白色，整齐，商品性好，耐贮藏；质地柔嫩，生熟食皆宜，口感风味佳。     

Scattered trees are keystone structures - Implications for conservation

Scattered trees are prominent features in many landscapes worldwide, including natural landscapes, cultural landscapes, and recently modified landscapes. The ecological importance of scattered trees is widely acknowledged in natural landscapes, but has not been sufficiently appreciated in human-modified landscapes. This paper shows that scattered trees are keystone structures in a wide range of landscapes. At the local scale, ecological functions of scattered trees include: provision of a distinct microclimate; increased soil nutrients; increased plant species richness; increased structural complexity; and habitat for animals. At the landscape scale, ecological roles include: increased landscape-scale tree cover; increased connectivity for animals; increased genetic connectivity for tree populations; and provision of genetic material and focal points for future large-scale ecosystem restoration. Furthermore, in disturbed landscapes, scattered trees often are biological legacies that provide ecological continuity through time. In combination, these ecological functions support the argument that scattered trees are keystone structures. That is, their contribution to ecosystem functioning is disproportionately large given the small area occupied and low biomass of any given tree, and the low density of scattered trees collectively. Because scattered trees fulfill unique functional roles in a wide range of scattered tree ecosystems, their loss may result in undesirable ecological regime shifts. A key management challenge in all landscapes with scattered trees is to maintain a balance between recruitment and mortality of trees in an appropriate spatial pattern. Meeting this challenge may represent an important step towards the genuine integration of conservation and production in human-modified landscapes.     

离体瘤胃上皮细胞在瘤胃代谢中的研究进展

反刍动物瘤胃上皮由基底层、棘层、粒层和角质层等四层组成,在瘤胃发酵终产物的代谢中具有重要作用,但其形态学受动物本身及饲喂制度等诸多因素的影响,造成细胞代谢活性上的差异。现在,应用离体瘤胃上皮细胞,使研究其组织形态学和代谢成为可能。     

大白菜游离小孢子培养技术研究进展

综述了影响大白菜小孢子培养的主要因素,阐述了影响大白菜小孢子植株再生的因素,总结了大白菜小孢子胚再生植株的继代与加代技术,提出了该技术存在的问题,并展望了这项技术在研究和生产实践中的应用前景.     

甘蓝型三棱角油菜新材料的遗传与选育研究初报

在复果油菜的试验研究中 ,发现一些具有三棱角类型角果的油菜植株 ,其角果呈三棱柱状 ,横截面为三角形、三室 ,角果皮为三瓣。以这些油菜植株为材料 ,进行了单株套袋自交、与复果油菜杂交、与白菜型油菜杂交、三棱角材料株系间杂交、自由授粉以及游离小孢子培养等一系列试验处理 ,初步研究了三棱角油菜的遗传特性 ,并对其角果特征和农艺性状进行了考查和描述。结果表明三棱角株平均每角粒数为 1 8.2 1粒 ,大于正常株 1 5 .30粒。目前 ,已分别选出三棱角株率为 1 0 0 .0 0 %、平均三棱角率为 32 .85 %的株系和三棱角率最高为94.1 2 %的植株。三棱角油菜的多粒特性在油菜高产育种中具有很大的增产潜力 ,无论在油菜遗传理论还是育种实践上都有重要意义