共查询到20条相似文献，搜索用时 484 毫秒
1.
肖望 《广东教育学院学报》2008,28(5):70-72
以贡蕉（Musa acuminata cv．Mas）未成熟雄花序来源的胚性愈伤组织为材料建立了贡蕉胚性细胞悬浮系（Embryogenic cell suspensions,ECS）,测定了其培养过程中培养物的鲜重、干重及培养液的PH值、阿拉伯半乳糖蛋白（Arabinogala ctan proteins,AGPs）含量等生长参数在培养过程中的变化动态．结果表明：在培养周期内,培养物的鲜重在继代后第24d达到高峰,干重在继代后第21d达到高峰;培养液中的pH值表现为先下降,第3d下降到最低,随后开始升高;培养液中AGPs含量随培养天数而增加,在第14d含量达到最高,随后保持稳定状态． 相似文献
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3.
王小平 《南京晓庄学院学报》2010,26(6):73-76
采用沙培法研究了扬花萝卜幼苗受到Hg2＋胁迫时,其根冠比、鲜重、干重、叶绿素a与b和MDA含量,以及SOD酶的活性等指标变化情况.结果表明,在低浓度1 mg.L-1～5 mg.L-1Hg2＋胁迫下,植株的根冠比大于对照,叶绿素含量略有增加;而高浓度20 mg.L-1～100 mg.L-1的Hg2＋胁迫下,植株的根冠比小于对照组（P≤0.05）,叶绿素含量呈下降趋势.实验进一步表明,在1 mg.L-1～5 mg.L-1Hg2＋胁迫下植株的干重、鲜重均略高于对照,而高浓度呈下降趋势.SOD酶的活性呈现出先升后降的变化,表现出植株对逆境环境具有一定的抗性;而MDA含量均呈增加趋势. 相似文献
4.
研究了不同浓度Hg~(2 )对水稻幼苗生长及其过氧化物酶活性的影响．结果表明,经Hg~(2 )胁迫的水稻幼苗,植株矮小,苗鲜重减少;低浓度Hg~(2 )使叶片叶绿素含量增加、POD活性升高．但随着Hg~(2 )浓度增大和处理天数增加,上述指标呈下降趋势,表明植物细胞遭受伤害． 相似文献
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以7个茶树品种为研究对象,模拟茶树叶片高温干旱失水过程,观测其叶片水分（相对含水量RWC、失水率RWL、自然饱和亏WSD）、叶绿素含量、叶绿素荧光参数等指标变化。结果表明,茶树叶宽、叶面积和叶片指数与RWL显著负相关。7种茶树叶片对高温失水反映迅速,在1～2 h内RWC、RWL迅速上升,WSD下降,肉桂、水仙保水能力较优,金观音最弱。光合色素含量测定表明,7个茶树品种的Chla含量处于同一水平（30.07～30.74 mg/L）,而Chlb在品种间差异显著（11.78～28.56 mg/L）,高温失水0～2 h内叶绿素总量除水仙外均下降。茶树叶绿素荧光参数变化对高温失水逆境的反映迅速,主要集中在0～3 h内：Y(Ⅱ)在0～2 h内下降、2～3 h间上升。茶树的光合色素与叶绿素荧光参数间有相关性,并且在正常条件下和高温失水时（3 h）的相关性存在差异。采用隶属函数值法对以上三类指标的综合评价得出,7个茶树品种在高温失水条件下的叶片综合性能表现从强到弱为：肉桂>九龙袍>丹桂>毛蟹>金观音>水仙>奇兰。 相似文献
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水杨酸(SA)在切花保鲜中的作用研究 总被引：3，自引：0，他引：3
用不同浓度的水杨酸（20mg·L^-1、40mg·L^-1、60mg·L^-1、80mg·L^-1、100mg·L^-1）作保鲜液来处理康乃馨切花,测定SA对康乃馨切花鲜重变化率的影响及水分平衡值的影响;结果如下：（1）不同浓度SA处理的康乃馨切花,鲜重都呈现先上升后下降的趋势。在达到最大鲜重天数、鲜重增加量、推迟鲜重降低三方面,浓度为80mg·L^-1SA的效果最明显。（2）五种不同浓度的SA保鲜液都能够改善康乃馨切花体内的水分状况,增加切花的保水能力,与对照相比五种不同浓度的SA都推迟了水分平衡值的降低,其中80mg·L^-1SA的保鲜液效果最好。 相似文献
7.
秦立金 《赤峰学院学报(自然科学版)》2011,27(6):50-51
采用盆栽试验的方法研究了土壤外源Cd污染处理对油菜幼苗生长的影响,结果表明：随着测定时间的延长,Cd在0～5mg/kg范围内,随着Cd浓度的增加,各项形态指标呈现增加趋势,Cd对油菜幼苗的生长起促进作用;当Cd的浓度增加到5mg/kg以后,各项指标均呈现下降趋势,Cd对油菜幼苗的生长起抑制作用.Cd对油菜叶绿素含量的影响十分明显,当Cd施用浓度达到5mg/kg时,各叶绿素含量达到最大值,以后随着Cd浓度的增加,叶绿素的含量呈下降趋势,且Cd对叶绿素a的影响大于对叶绿素b的影响.由此可知,5mg/kg很可能是油菜受Cd毒害的临界浓度. 相似文献
8.
目的:探究马齿苋种植密度对叶片功能性状的影响.方法:分别设置绝对密度、相对密度两组实验,即绝对密度[A(10株/m2),B(20株/m2),C(30株/m2),D(40株/m2),E(50株/m2),F(60株/m2),G(70株/m2),H(80株/m2)]、相对密度[a(100％),b(83.33％),c(71.43％),d(62.5％),e(55.5％)],测度各组马齿苋叶片功能性状(叶长、叶宽、叶质比、叶鲜重、叶绿素及叶形指数)的响应.结果:各处理组叶形指数对密度变化无显著性响应;绝对密度、相对密度对马齿苋其他各叶片功能性状有显著影响,各处理组叶长、叶宽、叶鲜重、叶质比、叶绿素、株鲜重、根冠比有显著性差异(P<0.05).随着绝对密度的增大,叶长、叶宽、叶质比均表现为先下降、后上升的趋势;叶鲜重、株鲜重、根冠比大幅显著下降,叶绿素含量有所抑制.结论:密度变化时,马齿苋叶形指数较稳定;叶长、叶宽、叶质比呈现出适应性变化,叶鲜重显著受到抑制;最适绝对密度10株/m2,最适相对密度83.33％. 相似文献
9.
综合研究生长因子对螺旋藻生长的影响,并选取影响比较明显的4种生长因子进行正交试验,结果表明,混合生长因子VBl0.5mg.L-1,VB1220g·L-1有利于螺旋藻的生长。对优化的混合生长因子,结合有机碳源葡萄糖、还原剂Vcc、激素NAA进行进一步正交试验,结论是在Zarrouk溶液基础上,添加葡萄糖1.5g·L-1、VBl250ug·L-1、VB1210ug·L-1、NAA0.5mg·L-1时有利于螺旋藻生长。与自养生长相比,混养培养时生物量增加了118.6%,单位叶绿素a含量减少了6.7%,藻胆蛋白含量增加了34.7%。 相似文献
10.
刘伦沛 《黔东南民族师专学报》2006,24(3):25-26,34
分离提纯小麦、水稻和玉米3种植物叶绿体的类囊体上的偶联因子CF1。利用分光光度法测定其酶促反应生成的无机磷的含量。得出小麦、水稻和玉米的偶联因子CF1的ATP酶活力分别为：333．9μmol（P）&;#183;（mg（ch1）&;#183;h）^-1，358．4μmol（P）&;#183;（mg（ch1）&;#183;h）^-1和485．1μmol（P）&;#183;（mg（ch1）&;#183;h）^-1．结果表明小麦、水稻和玉米3种植物叶绿体中偶联因子CF1的ATP酶的活性强弱不同。但小麦和水稻之间的酶活性差别较小。而两者与玉米之间的差别非常显著。 相似文献
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本文研究了氮肥用量对生菜产量的影响 ,结果表明 :生菜产量 (Y ,Kg)与氮肥用量 (X ,Kg)之间呈二次曲线相关 ,相关方程为Y =1916 .311+ 72 .489X - 2 .46 7X2 (r =0 .96 8) ;理论上氮肥用量为 14.76Kg(纯N)时 ,生菜可获得最高产量 2 45 4.1Kg ,在此试验基础上 ,提出了生菜配方专用肥方案 ,其N P2 O5 K2 O含量为 2 9 4 11。 相似文献
12.
酸雨——大气污染之产物 总被引：2，自引：0，他引：2
刘维俊 《蒙自师范高等专科学校学报》1994,(2)
早在十九世纪中期,英国化学家Robert Angus Smith就报道发现了酸雨,但当时并未引起人们的注意,直到欧洲的酸雨对生态环境产生严重危害,酸雨这一自然降水才得到人们的关注,随之对它的研究也有了很大发展。我国起步虽然较晚,近几年发展较快,有关的研究报导逐年增多。目前,对酸雨判别基准pH值的确定还处于争论之中,英国许多专家都主张pH小于5.0的降水为酸雨,本文仍以原来的基准值pH=5.6为标准,就日常生活中经常接触到的下雨这一自然现象,介绍一下天然降水与酸雨的区别,并分析酸雨的形成与人类对大气造成的污染的联系以及酸雨给人类带来的危害,从而告诉大家应当保护我们的环境。 相似文献
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In the present work, the fruits of four Morus species, namely Morus alba (white mulberry), Morus nigra (black mulberry), Morus laevigata (large white fruit), and Morus laevigata (large black fruit), were analyzed for proximate composition, essential minerals, and antioxidant potentials. For this purpose,
the ripe fruits were collected from the northern regions of Pakistan. The major nutritional components (moisture, ash, lipids,
proteins, fibres, carbohydrates, and total sugar) were found to be in the suitable range along with good computed energy.
Total dry weight, pH, and titratable acidity (percent citric acid) were (17.60±1.94)–(21.97±2.34) mg/100 g, (3.20±0.07)–(4.78±0.15),
and (0.84±0.40)%–(2.00±0.08)%, respectively. Low riboflavin (vitamin B2) and niacin (vitamin B3) contents were recorded in all the fruits, while ascorbic acid (vitamin C) was in the range from (15.20±1.25) to (17.03±1.71)
mg/100 g fresh weight (FW). The mulberry fruits were rich with regard to the total phenol and alkaloid contents, having values
of (880±7.20)–(1650±12.25) mg/100 g FW and (390±3.22)–(660±5.25) mg/100 g FW, respectively. Sufficient quantities of essential
macro-(K, Ca, Mg, and Na) and micro-(Fe, Zn, and Ni) elements were found in all the fruits. K was the predominant element
with concentration ranging from (1270±9.36) to (1731±11.50) mg/100 g, while Ca, Na, and Mg contents were (440±3.21)–(576±7.37),
(260±3.86)–(280±3.50), and (240±3.51)–(360±4.20) mg/100 g, respectivly. The decreasing order of micro-minerals was Fe>Zn>Ni.
The radical scavenging activity of methanolic extract of fruits was concentration-dependent and showed a correlation with
total phenolic constituents of the respective fruits. Based on the results obtained, mulberry fruits were found to serve as
a potential source of food diet and natural antioxidants. 相似文献
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应用植物离体快繁培养技术研究凤尾鸡冠瓶苗开花技术,结果表明:凤尾鸡冠的种子用0.1%的HgCl2灭菌8 min效果最好,成活率达到90%;最佳的增殖培养基配方为MS+NAA 0.1 mg·L-1+6-BA 1.0 mg·L-1+蔗糖20 g·L-1+琼脂10 g·L-1;经过壮苗后的植株在MS+PP3330.5 mg·L-1+NAA 0.01 mg·L-1+蔗糖20 g·L-1+琼脂10g·L-1培养基上培养,开花率最高,为81%;适当减少MS培养基中氮含量,能提高凤尾鸡冠瓶苗开花率;光照强度为3 000 Lx时,瓶苗开花率最高。 相似文献
15.
桑寄生植物从寄主板栗树的体内吸取水分和矿质营养,对寄主构成危害,其危害程度与寄生植物的生物学特性和环境条件有关,而不同种类的寄生植物对寄主个体和种群造成的危害亦不相同. 相似文献
16.
恒波长同步荧光法同时测定三种多环芳烃 总被引：1，自引：0，他引：1
建立了1,2-苯并蒽(1,2-BA)、苯并[k]芴(BkF)和3.4,8.9-二苯并芘(DBP)三种多环芳烃的恒波长同步荧光分析法。选择波长差Δλ=30nm,只需一次扫描,就可实现三组分的同时鉴别和定量测定。1,2-BA、BkF和DBP的线性范围分别为0—5.0μg.mL-1、0—1.6μg.mL-1和0—1.0μg.mL-1,检出限分别为0.58ng.mL-1、0.020ng.mL-1和0.013ng.mL-1。该方法简便、快速、灵敏,无需预分离,用于自来水、海水和溪水的分析,取得了良好的效果,回收率分别为87.5—104.0%,89.0—102.0%和88.3—102.5%。 相似文献
17.
Betul Apaydin Yildirim Saban Kordali Kubra Asena Terim Kapakin Fatih Yildirim Esra Aktas Senocak Serdar Altun 《Journal of Zhejiang University. Science. B》2017,18(6):501-511
The aim of this study was to evaluate the possible therapeutic or protective effects of Helichrysum plicatum DC. subsp. plicatum ethanol extract (HPE) against gentamicin-induced nephrotoxicity. Thirty-six Sprague Dawley male rats weighing between 200 and 250 g were used as live material. They were formed into six groups containing 6 rats each and were allowed to adapt to laboratory conditions for 7 d. Group I: control, 5% DMSO intraperitoneal (i.p.); Group II: HPE 100 mg/(kg·d) i.p.; Group III: HPE 200 mg/(kg·d) i.p.; Group IV: gentamicin as 80 mg/(kg·d) i.p.; Group V: gentamicin as 80 mg/(kg·d) i.p.+HPE 100 mg/(kg·d) i.p.; and Group VI: gentamicin as 80 mg/(kg·d) i.p.+HPE 200 mg/(kg·d) i.p. for 8 d. Following treatment, serum, liver, and kidney tissues were used to assess blood urea nitrogen (BUN), creatinine, enzymatic and non-enzymatic antioxidants, and lipid peroxidation. Gentamicin significantly increased serum BUN, creatinin, and liver and kidney levels of malondialdehyde (MDA). It also decreased the activity of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD). Treatment with the HPE 100 mg/kg reversed gentamicin-induced alterations as evidenced by decreased serum BUN and creatinin, liver and kidney oxidant marker, and tubular necrosis as well as by an increase in antioxidant enzymes. It was found that HPE 200 mg/kg significantly increased liver and kidney tissue MDA levels in nephrotoxicity in rats. As a result, these findings support the proposition that HPE in 100 mg/kg dose demonstrates in the kidney and liver as free radicals and scavenger to prevent the toxic effects of gentamicin in both the biochemical and histopathology parameters. 相似文献
18.
Miles Barker 《Science & Education》2002,11(3):293-304
Scientists' attempts to understand plant functions by ascribing animal functions to plants – the analogist tradition, derived from Aristotle – began to be superseded in Europe by an experimentalist tradition in the seventeenth century. In classrooms today, science students learning about plant functions (exemplified here by the topic of transpiration) face a parallel dilemma: the pitching of their own habitual mental processes of analogy building (enhanced by the suggestive morphology of plants)and the persuasiveness of everyday language (for example, about plants and water)against the new experimental evidence presented by the teacher. In the case oftranspiration, six practical suggestions whereby teachers can support students in thisstruggle to put their thoughts (especially everyday mental models) in accordance withthings (classroom experimental evidence) are advanced. The wider implications forhow we teach about Living Things, and how we view the status of analogies in sciencegenerally, are discussed. 相似文献
19.
Cadmium accumulation in different pakchoi cultivars and screening for pollution-safe cultivars 总被引：4，自引：0，他引：4
Ying Chen Ting-qiang Li Xuan Han Zhe-li Ding Xiao-e Yang Ye-fei Jin 《Journal of Zhejiang University. Science. B》2012,13(6):494-502
The selection and breeding of pollution-safe cultivars (PSCs) is a practicable and cost-effective approach to minimize the influx of heavy metal to the human food chain. In this study, both pot-culture and field experiments were conducted to identify and screen out cadmium pollution-safe cultivars (Cd-PSCs) from 50 pakchoi (Brassica rapa L. ssp. chinensis) cultivars for food safety. When treated with 1.0 or 2.5 mg/kg Cd, most of the pakchoi cultivars (>70%) showed greater or similar shoot biomass when compared with the control. This result indicates that pakchoi has a considerable tolerance to soil Cd stress. Cd concentrations in the shoot varied significantly (P<0.05) between cultivars: in two Cd treatments (1.0 and 2.5 mg/kg), the average values were 0.074 and 0.175 mg/kg fresh weight (FW), respectively. Cd concentrations in the shoots of 14 pakchoi cultivars were lower than 0.05 mg/kg FW. In pot-culture experiments, both enrichment factors (EFs) and translocation factors (TFs) of six pakchoi cultivars were lower than 1.0. The field studies further confirmed that the Hangzhouyoudonger, Aijiaoheiye 333, and Zaoshenghuajing cultivars are Cd-PSCs, and are therefore suitable for growth in low Cd-contaminated soils (≤1.2 mg/kg) without any risk to food safety. 相似文献
20.
在红曲霉发酵酿造茶酒的原料中添加制茶下脚料,实验对比测定了发酵前后各营养成分的变化,结果表明：发酵前物料中各营养含量分别为,总糖（302.2±3.29） mg/g,还原糖（126.3±7.46）mg/g,多糖（175.9±9.05） mg/g,粗纤维27.1%,氮（40.64±1.06） mg/g,游离氨基酸（47.04±0.75） mg/g。发酵后物料中总糖（199.1±1.64） mg/g,还原糖（29.07±0.34） mg/g,多糖（170.0±1.30） mg/g,粗纤维18.8%,氮（37.02±0.86） mg/g,游离氨基酸为0 mg/g。发酵前后物料总重量利用率39.4%,各营养物质的转化率分别为总糖60.06%,还原糖86.01%、多糖3.35%、粗纤维30.62%、氮8.91%、氨基酸为100%。发酵茶酒的酒精度达到13%。 相似文献