巨桉凋落叶分解对菊苣生长及光合特性的影响

采用盆栽试验,研究了巨桉凋落叶分解初期对菊苣幼苗生长和光合生理特性的影响.试验设置A₁(30 g·pot^-1)、A₂(60 g·pot^-1)、A₃(90 g·pot^-1)和对照（CK）4个凋落叶水平,将各处理的凋落叶分别与12 kg土壤混合后装盆,播种菊苣.待A₃处理植株的第3片真叶完全展开后测定菊苣光合生理指标及相关生长指标.结果表明：巨桉凋落叶分解初期明显抑制了菊苣生物量积累、叶面积的增加及光合色素的合成,且随着凋落叶施入量的增加抑制作用加大;菊苣叶片胞间CO₂浓度增加,而净光合速率、气孔导度和蒸腾速率均显著低于对照;随土壤中凋落叶含量的增加,除CO₂补偿点呈增加趋势外,其他光响应和CO₂响应的特征参数都呈明显下降趋势,并与对照差异显著.巨桉凋落叶分解过程中,其化感物质逐步释放并作用于受体植物,抑制其光合色素合成和光合作用,降低其环境适应能力,从而抑制菊苣的生长.     

巨桉凋落叶分解对菊苣生长及光合特性的影响

采用盆栽试验,研究了巨桉凋落叶分解初期对菊苣幼苗生长和光合生理特性的影响.试验设置A₁(30 g·pot^-1)、A₂(60 g·pot^-1)、A₃(90 g·pot^-1)和对照（CK）4个凋落叶水平,将各处理的凋落叶分别与12 kg土壤混合后装盆,播种菊苣.待A₃处理植株的第3片真叶完全展开后测定菊苣光合生理指标及相关生长指标.结果表明：巨桉凋落叶分解初期明显抑制了菊苣生物量积累、叶面积的增加及光合色素的合成,且随着凋落叶施入量的增加抑制作用加大;菊苣叶片胞间CO₂浓度增加,而净光合速率、气孔导度和蒸腾速率均显著低于对照;随土壤中凋落叶含量的增加,除CO₂补偿点呈增加趋势外,其他光响应和CO₂响应的特征参数都呈明显下降趋势,并与对照差异显著.巨桉凋落叶分解过程中,其化感物质逐步释放并作用于受体植物,抑制其光合色素合成和光合作用,降低其环境适应能力,从而抑制菊苣的生长.     

巨桉根系分解对菊苣生长及光合特性的影响

巨桉是我国退耕还林过程中采用的重要速生树种之一,被广泛用于人工造林。采用盆栽试验,研究了巨桉根系分解初期对菊苣幼苗生长和光合生理特性的影响。试验设置A1(50 g/盆)、A2(100 g/盆)和对照(CK)3个根系水平,将各处理的根系分别与10 kg土壤混合后装盆,播种菊苣。待A2处理植株的第3片真叶完全展开后测定菊苣光合生理指标及相关生长指标。结果表明:在巨桉根系分解初期,明显抑制了菊苣高生长、根生长、生物量积累、叶面积扩展及光合色素的合成,且随着根系添加量的增加抑制作用加大;菊苣叶片胞间CO2浓度(Ci)增加,而净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)均显著低于对照;随土壤中根系含量的增加,除CO2补偿点(CCP)呈增加趋势外,其他光响应和CO2响应的特征参数均呈明显的下降趋势,并与对照差异显著;各生长指标除与胞间CO2浓度呈现出负相关外,与其它光合特征参数、光合色素以及相应的响应曲线参数之间均呈现出显著或极显著的正相关关系;通过GC-MS检测表明,巨桉根系中含有2,6-二叔丁基对甲酚、N-甲基苯乙胺等多种具有化感潜力化学物质,在其分解过程中,这些化感物质逐步释放并作用于受体植物,抑制其光合色素合成和光合作用,降低其环境适应能力,从而抑制菊苣的生长。     

天竺桂凋落叶对凤仙花生长和光合特性的影响

采用盆栽实验,通过向土壤(每盆8kg)中添加0g·pot-1(CK)、20g·pot-1(L)、40g·pot-1(M)和80g·pot-1(H)天竺桂(Cinnamomum japonicum)凋落叶,模拟其自然分解对凤仙花(Impatiens balsamina)生长和光合特性的影响。结果显示:(1)添加天竺桂凋落叶M和H处理下,凤仙花生物量和地径均显著降低,而株高无明显变化;其叶绿素含量受到显著抑制,净光合速率(Pn)和水分利用效率(WUE)显著低于CK,而气孔导度(Gs)、胞间二氧化碳浓度(Ci)和蒸腾速率(Tr)3个气体交换参数显著高于CK。(2)Pn-PAR曲线和Pn-Ci曲线拟合表明,凤仙花在光饱和以及CO2饱和状态下的最大净光合速率(Pn max)、表观量子效率(AQY)、暗呼吸速率(Rd)、RuBP羧化效率(CE)和光呼吸速率(Rp)均随添加天竺桂凋落叶处理量的增加而呈下降趋势。(3)添加天竺桂凋落叶36d和67d时对凤仙花生长影响不明显,而处理58d时有明显抑制作用。研究表明,在模拟天竺桂凋落叶自然分解的土壤环境中,凤仙花的光合色素含量降低,抑制了其光合能力,对环境适应能力降低,导致凤仙花的生长受到抑制。     

巨桉不同状态叶片浸提液对萝卜幼苗形态和抗性生理特性的影响

以珍珠岩作为基质,选择4年生巨桉(Eucalyptus grandis)嫩叶(T1)、老叶(T2)、表层凋落叶(T3)、腐解凋落叶(T4)4种状态的叶片,每种状态叶片设置3个浸提液浓度水平[分别称取风干叶片30g、15g和7.5g加入900mL蒸馏水进行浸提,以蒸馏水为对照(CK)],采用水培法研究了不同状态叶片浸提液对萝卜(Raphanus sativus)幼苗形态生长和抗性生理特性的影响。结果显示:(1)巨桉不同状态叶片浸提液显著抑制了萝卜幼苗的根长,其中嫩叶的抑制作用最强,腐解凋落叶抑制作用最弱。(2)各状态叶片浸提液处理后萝卜幼苗中过氧化氢酶(CAT)和过氧化物酶(POD)的活性均呈现升高趋势,嫩叶各浓度处理以及其他状态叶片的高浓度处理下超氧化物歧化酶(SOD)活性升高,而其余浓度处理的SOD活性降低。(3)各状态叶片浸提液处理萝卜幼苗的丙二醛(MDA)含量在低浓度处理时低于CK,其余处理下则高于CK。(4)嫩叶各浓度处理萝卜幼苗的可溶性糖(SS)含量显著高于CK,且随着老叶和表层凋落叶浸提液浓度的升高,幼苗SS含量先升后降,腐解凋落叶各浓度处理下则呈渐增的趋势;而可溶性蛋白(SP)含量则随浸提液浓度的增加而升高,且T2和T3两种状态叶片的各浓度处理与CK差异显著。研究表明,巨桉不同状态叶片浸提液对萝卜幼苗生长和抗性生理产生了强烈的抑制作用,其中以嫩叶最强,老叶和表层凋落叶次之,腐解凋落叶最弱。     

蓝桉凋落叶分解对菠菜生长及光合特性的影响

通过盆栽试验,模拟蓝桉(Eucalyptus globulus)凋落叶在土壤中分解对受体植物菠菜(Spinacia oleracea)生长及光合特性的影响,设置L30(30 g/盆)、L60(60 g/盆)、L90(90 g/盆)和L120(120 g/盆)4个凋落叶施用水平,对照(CK)不加凋落叶。结果表明:(1)在分解30 d时,低量的凋落叶(L30)未抑制菠菜生物量的积累,而中量和高量处理(L60、L90和L120)下其生物量显著降低(P0.05);在凋落叶分解50 d后,蓝桉凋落叶的化感抑制效应已经减弱,仅L120仍然抑制菠菜生物量的积累;(2)一定量的凋落叶(L30和L60)对菠菜叶绿素的合成有促进作用,而凋落叶超过一定量时(L120)转为抑制作用,在凋落叶分解28 d时相对不明显,40 d后逐渐显现;(3)经凋落叶处理的菠菜叶片胞间CO2浓度(Ci)、气孔导度(Gs)及蒸腾速率(Tr)均显著高于对照(CK)(P0.05),而净光合速率(Pn)在L30处理下最高,L60和L90处理与CK差异不显著,仅L120处理显著低于CK(P0.05);(4)光响应与CO2响应曲线的特征参数表观量子效率(AQY)、最大净光合速率(Pmax)、光饱和点(Lsp)、光补偿点(Lcp)、暗呼吸速率(Rd)、Ru BP表观羧化效率(CE)和光呼吸速率(Rp)在L30处理下高于CK,其余凋落叶处理均低于CK,而CO2饱和点(Csp)、CO2补偿点(Ccp)随凋落叶量的增加而升高。综合各指标可见,少量的蓝桉凋落叶分解(L30)可通过增加叶绿素含量,提高对光和CO2的利用能力促进菠菜的光合作用,进而促进其生长,而凋落叶超过一定量时(L90—L120)则起到相反的作用。     

美洲黑杨凋落叶分解初期对小白菜生长的影响

采用盆栽试验,研究了美洲黑杨(Populus deltoides)凋落叶分解初期对受体植物小白菜(Brassica chinensis)生长和生理的影响。试验设置0、30、60和90 g/盆4个凋落叶施用水平(分别记作CK、L30、L60和L90)。同时,为检验凋落叶施入是否对土壤通气透水性产生明显影响进而影响受体植物的生长,用蒸煮后的凋落叶设置平行空白试验,即30、60、90 g/盆3个蒸著后的凋落叶处理(分别记作Z30、Z60和Z90)。将各处理的凋落叶分别与7 kg土壤混合,播种小白菜。在播种后50、80 d测定小白菜株高和生理指标。结果表明:1)高量(L90)凋落叶下小白菜的高生长和鲜重于50 d时被显著抑制,80 d时长势恢复正常;2)80 d时各处理净光合速率(Pn)与CK水平相当,色素含量略低于CK;3)50、80 d时,低(L30)、中(L60)量处理的超氧化物歧化酶(SOD)活性无明显变化,高量处理下SOD活性升高;4)各处理丙二醛(MDA)含量在50、80 d时与CK均无显著差异。总的来看,杨树各凋落叶量处理对小白菜的影响表现为:低、中量促进,高量抑制,而经蒸煮后的凋落叶处理间差异不显著。表明,低、中量杨树凋落叶在土壤中分解对小白菜生长及生理代谢的影响主要表现为促进作用,而施入高量凋落叶的初期,化感抑制作用明显。     

接种促生菌对尾巨桉—降香黄檀混作幼苗光合生理特性和生长的影响

该试验以盆栽尾巨桉和降香黄檀幼苗为材料,设置BM处理(尾巨桉接种巨大芽孢杆菌,降香黄檀不接种)、RJ处理(降香黄檀接种大豆根瘤菌,尾巨桉不接种)以及对照组(CK,尾巨桉和降香黄檀均不接菌),探究接种2种促生细菌对尾巨桉-降香黄檀混作幼苗的光合生理、生长和生物量积累及分配的影响,明确在混交体系中接种促生菌对促进植物生长的优势。结果显示:(1)BM处理显著降低尾巨桉的叶绿素含量(P<0.05),BM和RJ处理均提高了尾巨桉和降香黄檀的苗高、地径以及叶片的氮素含量、净光合速率、气孔导度、蒸腾速率,但降低了胞间CO_(2)浓度。(2)RJ处理显著提高了尾巨桉及降香黄檀叶片和全株生物量,BM处理仅显著提高降香黄檀根、茎、叶、全株的生物量和尾巨桉叶的生物量(P<0.05)。(3)各接菌处理条件下2种植物幼苗叶片净光合速率与其生物量呈显著正相关。研究表明,接种大豆根瘤菌和巨大芽孢杆菌均促进尾巨桉-降香黄檀混作幼苗的生理代谢,2种促生菌能通过增强光合作用来促进植株生物量的累积;从植株生物量变化来看,接种菌株的利他作用更明显。     

不同生境条件下核桃凋落叶次生代谢物质的差异及其分解初期对小白菜光合生理特性的影响

采用气质联用技术(GC-MS)分析了秦巴山区大巴山南坡和川西高山峡谷区两个不同生境条件下生长的核桃(Juglans regia)凋落叶中次生代谢物质的差异,并采用盆栽试验,研究了这两个地区核桃凋落叶分解对小白菜(Brassica chinensis)生长和光合生理特性的影响。试验设置F0(0 g/pot)、F1(30 g/pot)、F2(60 g/pot)、F3(120 g/pot)和F4(180 g/pot)5个凋落叶施用水平,分别将各处理的凋落叶与8 kg土壤混合后装盆,播种小白菜。分别于播种后20、45和75 d测定小白菜的生长指标,待凋落叶最高添加量处理组F4植株的第3片真叶完全展开后,测定小白菜的光合生理指标。结果表明:(1)采用GC-MS共检测出8类21种相对含量1%的次生代谢物质,其中,川西高山峡谷区核桃7类15种,相对含量总计56.03%,秦巴山区大巴山南坡核桃5类12种,相对含量总计51.46%。川西高山峡谷区核桃白菖油萜、茅苍术醇、β-桉叶醇、6,10,14-三甲基-2-十五烷酮、亚麻油酸、硬脂酸、十八醇、γ-谷甾醇、豆甾-4-烯-3-酮等为报道较多的潜在化感物质,其相对含量高于秦巴山区大巴山南坡核桃,而角鲨烯、δ-生育酚、黑麦草内酯等潜在的化感物质相对含量则低于秦巴山区大巴山南坡核桃;(2)播种后20 d和45 d,两个地区各添加量核桃凋落叶分解对小白菜生物量积累均产生显著的抑制作用,但75 d后效应减弱;(3)在凋落叶分解初期,小白菜叶片光合色素合成受到明显抑制,且随着凋落叶添加量增加抑制作用增强,与此同时,净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)也明显受到核桃凋落叶分解的抑制;(4)总体来看,川西高山峡谷区核桃凋落叶化感作用大于秦巴山区大巴山南坡核桃凋落叶,这可能是由于前者经受较多的环境胁迫,体内积累了更多的酮类、烯烃、醇类和甾族化合物等化感物质造成的。     

樟子松幼苗生长及光合特性对强风沙流吹袭的响应

为了解樟子松幼苗对不同时间强风沙流吹袭的生理生态响应,2013年春季在内蒙古科尔沁沙地研究了8级大风风沙流(风速18m·s-1,风沙流强度173g·cm-1·min-1)吹袭10、20和30min下樟子松幼苗生长与光合特性的变化。结果显示:(1)随着风吹时间的增加,樟子松的株高生长量减少、茎粗生长加快,落叶数量增加,其中30min处理与CK相比的株高生长量下降52.63%,茎粗生长量增加233.30%,落叶指数增加466.70%。(2)风沙流吹袭没有改变樟子松幼苗的净光合速率、蒸腾速率、气孔导度和胞间CO2浓度的日变化规律,但日光合峰值下降,日最大蒸腾速率增加;与CK相比,30min处理的日最大光合速率下降22.69%,日最大蒸腾速率增加11.89%。(3)随风吹时间增加,其叶片温度、叶片相对含水量、日均光合速率、水分利用效率下降,30min处理较CK依次下降0.60%、4.37%、28.57%和31.58%,且日均蒸腾速率、气孔导度和胞间CO2浓度增加,30min处理较CK依次增加6.25%、6.67%和12.60%。研究表明,在持续风沙流胁迫下,樟子松幼苗光合作用受到抑制,蒸腾耗水增加,水分利用效率降低;樟子松幼苗生长速率降低主要源于光合面积减少和光合作用受到抑制,而其光合速率下降主要因幼苗叶片叶温和叶片含水量下降所致,蒸腾速率的增加主要源于气孔导度的增加;为了适应风沙流持续吹袭的胁迫,樟子松幼苗采取了降低株高生长速率,加快茎粗生长速率的适应策略。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

The mechanism of hatching of eggs of Haemonchus contortus

Fluid collected from hatching eggs of Haemonchus contortus contained a lipase which hydrolysed 2-naphthyl laurate (about 0·7 μmol naphthol freed /h/10⁶ eggs). The fluid also hydrolysed l-leucinamide (about 2·3 μmol leucine freed/h/10⁶ eggs). The fluid when added to normal or heated eggs caused ‘hatching’. ‘Hatching’ also occurred in exsheathing fluid from infective juveniles and in a preparation of pancreatic lipase containing leucine aminopeptidase. A purified mammalian leucine aminopeptidase in combination with several different lipases did not attack egg shells.The ‘spontaneous’ hatching of eggs of H. contortus was strongly inhibited by 1,10-phenanthroline, 10^?3M, and this inhibition was reversed by Zn²⁺. However, the inhibition of ‘hatching’ of eggs in externally applied hatching fluid, or the hydrolysis of leucinamide in hatching fluid was generally less marked.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.