兰州市4种常见园林观花地被植物抗旱性比较研究

以兰州市4种常见园林观花地被植物为研究对象,通过采用人工模拟不同土壤水分胁迫,分组测定各参试植物的株高、叶绿素、脯氨酸、丙二醛含量等指标, 并用隶属函数法对其抗旱性进行综合评价。结果表明:随着干旱胁迫的加剧,植物的株高、叶绿素含量与对照相比呈不同程度的下降趋势,金盏菊(Calendula officinalis)株高降幅最大,叶绿素含量万寿菊(Tagetes erecta)下降高于其他植物;叶片脯氨酸和丙二醛的含量随干旱程度的增加而升高,万寿菊脯氨酸含量增幅较大,丙二醛含量金盏菊增幅较大;4种地被植物的抗旱性强弱顺序依次为金盏菊> 矮牵牛(Petunia hybrida)> 一串红(Salvia splendens)> 万寿菊。研究表明,植物的株高、脯氨酸含量、丙二醛含量与其实际抗旱性密切相关,可作为评价园林地被植物抗旱性的有效指标。     

采煤沉陷区苦草的生物学特性及其竞争机制

采煤活动所致的动态沉陷湿地具有动态性、高潜水位和生态脆弱性等特点,探明此类人工重构湿地的水生植物群落的生物学特性及其竞争机制,有助于为采煤沉陷区湿地水生植物群落修复提供科学依据。本研究以淮南潘集区人工构建的苦草群落(Ass. Vallisneria natans)为例,采用样方调查法,研究苦草的生物学特性及其与其他水生植物的竞争机制。结果表明,1)沉陷区苦草的生物学特性与浅水湖泊较一致。主要表现在苦草的繁殖方式、传粉方式、生活史方面,但研究区苦草以有性繁殖为主。2)沉陷区苦草能与以种子萌发形成的水烛群丛(Ass. Typha angustifolia)共生,但生物量低;在与形成两年以上的水烛群丛竞争中处于劣势,在水烛群丛盖度达到90%时苦草逐渐消失。3)沉陷区苦草在与浮叶植物莕菜群丛(Ass. Nymphoides peltatum)、苹群丛(Ass. Marsilea quadrifolia)竞争中处于弱势,其盖度、株高、生物量等指标都明显下降。4)沉陷区苦草在与沉水植物竹叶眼子菜群丛(Ass. Potamogeton malaianus)竞争中处于劣势,苦草与沉水植物黑藻群丛(Ass. Hydrilla verticillata)、狐尾藻群丛(Ass. Myriophyllum verticillatum)、大茨藻群丛(Ass. Najas marina)、金鱼藻群丛(Ass. Ceratophyllum demersum)占据不同水层空间,种间竞争不强烈,能较好地共存。总之,苦草较之于相似生长型的植物具有较明显的竞争优势,对于具有不同生活型,尤其是挺水植物和浮叶植物,处于竞争劣势。     

The effects of replacement of whole‐plant corn with oat and common vetch on the fermentation quality,chemical composition and aerobic stability of total mixed ration silage in Tibet

The objective of this experiment was to evaluate the effects of replacement of whole‐plant corn with oat and common vetch on the fermentation quality, chemical composition and aerobic stability of total mixed ration (TMR) silage in Tibet. Four TMR that varied in the forage sources on dry matter basis were used: (i) 52% whole‐plant corn (Control); (ii) 43% oat + 12% common vetch (OC3.6); (iii) 38% oat + 18% common vetch (OC2.2); and (iv) 33% oat + 23% common vetch (OC1.5). Silos were opened on day 45 and then subjected to an aerobic stability test for 12 days. The results showed that all silages were well preserved with low pH and NH₃‐N, and high lactic acid and V‐scores. With the increasing proportion of common vetch, crude protein, ether extract increased (P < 0.05), and neutral detergent fiber and acid detergent fiber decreased (P < 0.05). Under aerobic conditions, treated silages were more stable than the control silage as indicated by lower (P < 0.05) pH and yeast population. It was concluded that replacement of whole‐plant corn with oat and common vetch had no unfavorable effects on the fermentation quality and improved crude protein content and aerobic stability of TMR silage. OC2.2 silage was the best among three treated TMR silages.     

植物单宁调控乳酸菌特性的研究进展及其在生产中的应用

单宁是植物的一种次级代谢产物,能够结合蛋白质形成复合物,在微生物发酵中有特殊生理作用。目前国内外学者对单宁结构、生物学特性和抑菌作用进行了深入研究。本文系统阐述了植物单宁对乳酸菌生长特性的调控作用,包括植物单宁抑菌性、不同种类乳酸菌对植物单宁适应性和代谢途径等,并对单宁在反刍动物营养与饲草加工利用中的应用进行了展望。     

高羊茅雄性不育株花粉母细胞减数分裂染色体行为观察

采用卡宝品红染色制片法,对高羊茅(Festuca arundinacea)雄性不育植株花粉母细胞减数分裂过程及异常行为进行观察,结果发现,高羊茅减数分裂进程与小花大小、花药长度、色泽有较为密切的关系。减数分裂周期具有不同步性,同一制片中可观察到2～4个不同时期的分裂相,这种现象是高羊茅在进化过程中环境适应的一种表现,有利于增强种群繁殖稳定性。本研究还发现,减数分裂过程中存在大量单价体、染色体桥、落后染色体、不均等分离、微核、三分体等异常现象,初步分析确定这些小孢子异常分裂是导致高羊茅花粉败育的重要原因之一。     

Further evidence that in African acacia,white is a warning colour to herbivores: the white pseudo-galls of Vachellia seyal

Pseudo-galls of three East African acacia (Vachellia) species were compared to determine the correlates of gall colour and their potential defensive functions. Although all three species produce white thorns, the pseudo-galls of V. gerrardii and V. drepanolobium are dark coloured. In contrast, pseudo-galls of V. seyal var. fistula are white. Associated with this, they are thin-walled and poorly used by aggressive mutualistic ants. We suggest that this weak functionality is compensated for by the highly visible white colour. This aposematism may also involve mimicry as only the fistula variety of V. seyal has galls and only this variety co-occurs with other Vachellia species that have functional galls. Vachellia seyal seyal does not have pseudo-galls and this variety does not occur with other Vachellia species that have pseudo-galls.     

超声波预处理对全株青贮玉米品质的影响

为研究超声波预处理对全株青贮玉米品质的影响,设置空白对照组、超声处理组(5、10、15、20、25 min)和乳酸菌对照组进行青贮玉米品质研究.结果表明:15 min和20 min超声处理后,全株玉米青贮饲料感官评定属于优良级.与对照组相比,超声处理后饲料的pH和氨氮比分别降低7.71％和7.82％,乳酸和乙酸含量分别...     

五种藏医药用植物叶解剖结构特征的研究

通过对分布于青藏高原东北部海拔 380 0～ 440 0m处生长的五种高山藏医药用植物结构进行的显微观察。进一步探讨青藏高原高山植物独特生理结构与自然环境间的相互影响及适应性。结果表明 :五种植物的叶表皮细胞单层 ,有的叶表面密被表皮毛 ,角质层厚 ;叶肉组织中栅栏组织均多层 ,并普遍形成发达的通气组织。这些特征是高寒地区低氧、低温、强辐射等自然条件长期作用的结果。     

轮状病毒转基因植物疫苗的研究进展

轮状病毒病是引起人和动物肠胃炎的一种传染病,发病率和死亡率较高,至今没有特效药可以治疗,传统疫苗预防效果不佳。随着生物技术的不断发展,一种新型的转基因植物疫苗有望解决这个难题。人类和动物食用了这种转基因植物之后,就可以获得抗体,产生免疫力,以预防此病。     

紫花苜蓿对九种杂草的化感作用

试验运用生物测定法研究了紫花苜蓿叶化感物质对九种受体植物的作用.结果表明,紫花苜蓿叶提取物对多变小冠花的发芽势和发芽率具有抑制作用,与对照差异显著(P＜0.05);提取物对高羊茅种子的发芽势有促进作用,与对照差异显著(P＜0.05),其最终发芽率也增加(P＜0.05);除狗尾草外,其余八种受体植物的胚根长度都受到紫花苜蓿叶提取物的抑制,与对照的差异均显著(P＜0.05);提取物对稗草、狗尾草、高羊茅、毛马唐和多变小冠花的苗长具有促进作用,与对照差异均显著(P＜0.05);反枝苋的苗长则受到抑制(P＜0.05);提取物对受体植物的幼苗鲜重均有不同程度的影响,虎尾草、匍匐翦股颖、巴哈雀稗、反枝苋和多变小冠花幼苗鲜重明显降低,与对照差异达显著水平(P＜0.05).