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1.
美洲黑杨(Populus deltoides)是长江中下游及江淮平原重要的造林树种,目前广泛栽培的美洲黑杨既有雄株品系,也有雌株品系。为了解镉(Cd)胁迫条件下美洲黑杨雌、雄株的耐受性差异,采用盆栽实验,研究Cd污染(10 mg·kg–1)条件下美洲黑杨雌、雄株气体交换速率、CO_2响应曲线、叶绿素荧光参数、渗透调节能力、激素含量的响应特征,以及接种丛枝菌根真菌(Rhizophagus intraradices)对受Cd胁迫美洲黑杨雌、雄株的生理效应。结果表明:(1)Cd胁迫下,美洲黑杨雌、雄株净光合速率、气孔导度、胞间CO_2浓度、蒸腾速率、光系统II(PSII)最大光化学量子产量、PSII有效光化学量子产量、光化学淬灭系数、最大羧化速率、最大电子传递速率、磷酸丙糖利用速率均不同程度降低,雌株的下降幅度更大,接种丛枝菌根真菌的雌株的以上参数有了不同程度的恢复,但对雄株没有明显影响;(2)Cd胁迫下,美洲黑杨雌雄株的脯氨酸含量均显著增加,接种丛枝菌根真菌进一步提高了雌株的脯氨酸含量;(3)Cd胁迫下,美洲黑杨雌、雄株叶片生长素含量下降,脱落酸含量增加,雌株的变化幅度更大,接种丛枝菌根真菌有利于恢复雌株激素的平衡。由此可见,与雄株相比,Cd胁迫对美洲黑杨雌株气体交换速率和碳固定能力的负面影响更大,植株光合机构受损更严重,激素平衡更易受到影响,表现出更弱的胁迫耐受性;接种丛枝菌根真菌有利于增强美洲黑杨雌株的渗透调节能力并在一定程度上恢复雌株的固碳能力和激素平衡,但菌根对雄株的效应并不显著。  相似文献   

2.
丛枝菌根真菌(AMF)对雌雄异株植物根系生长,尤其是对邻近生长的不同雌雄个体的影响还鲜有研究。该研究以泥土:河沙:蛭石体积比为1:1:1的混合物为培养基质,分别在雄-雄、雌-雌和雄-雌3种组合栽培模式下对青杨(Populus cathayana)雌雄幼苗进行接种和不接种摩西球囊霉(Funneliformis mosseae)处理,通过比较接种AMF与否雌雄植株根系在侵染率、生物量、形态、碳、氮含量等方面的差异来分析AMF对青杨雌雄幼苗根系生长发育的影响。结果发现:与对照组相比,接种AMF对3种栽培模式下青杨雌雄植株的侵染率、根干质量、根系形态(除分枝强度、比表面积)和碳、氮含量影响显著。此外,不同性别组合模式对青杨雌雄植株的根干质量、根系形态和碳、氮含量影响显著。接种AMF后,与雌-雌合栽模式下的雌株相比,雄-雌合栽模式下雌株的根干质量、氮含量都有不同程度的提高,根系形态发生改变;而与雄-雄合栽模式下的雄株相比,雄-雌合栽模式下雄株的相应指标出现降低或轻微增加。该研究表明AMF对不同性别组合模式下青杨植株根系生长具有显著促进作用,尤其是雄-雌合栽模式下AMF接种最有利于雌株根系的生长发育。  相似文献   

3.
丛枝菌根真菌(AMF)对雌雄异株植物根系生长, 尤其是对邻近生长的不同雌雄个体的影响还鲜有研究。该研究以泥土:河沙:蛭石体积比为1:1:1的混合物为培养基质, 分别在雄-雄、雌-雌和雄-雌3种组合栽培模式下对青杨(Populus cathayana)雌雄幼苗进行接种和不接种摩西球囊霉(Funneliformis mosseae)处理, 通过比较接种AMF与否雌雄植株根系在侵染率、生物量、形态、碳、氮含量等方面的差异来分析AMF对青杨雌雄幼苗根系生长发育的影响。结果发现: 与对照组相比, 接种AMF对3种栽培模式下青杨雌雄植株的侵染率、根干质量、根系形态(除分枝强度、比表面积)和碳、氮含量影响显著。此外, 不同性别组合模式对青杨雌雄植株的根干质量、根系形态和碳、氮含量影响显著。接种AMF后, 与雌-雌合栽模式下的雌株相比, 雄-雌合栽模式下雌株的根干质量、氮含量都有不同程度的提高, 根系形态发生改变; 而与雄-雄合栽模式下的雄株相比, 雄-雌合栽模式下雄株的相应指标出现降低或轻微增加。该研究表明AMF对不同性别组合模式下青杨植株根系生长具有显著促进作用, 尤其是雄-雌合栽模式下AMF接种最有利于雌株根系的生长发育。  相似文献   

4.
AM真菌与镉互作影响桑生长和无机元素吸收转运   总被引:1,自引:0,他引:1  
《菌物学报》2017,(7):996-1009
为评价Cd胁迫下接种AM真菌(AMF)对减轻桑树Cd毒害及Cd迁移规律的影响,采用了分室培养法开展试验。在菌根室种植无菌桑苗并接种AMF(Gigaspora rosea),菌丝室设置兼菌丝收集器功能的Cd陷阱。陷阱中的Cd处理浓度为0、5、20、40mg/kg,菌根室每室种植3株桑苗,6个重复,对照不接种AMF。培养60d后检测桑苗的菌根侵染率、不同部位的生长量、AMF菌丝生物量、4种矿质营养元素组分及Cd在AMF菌丝体和桑株中的定位及转运情况。结果表明:在0–40mg/kg的Cd处理下,不接种AMF处理的对照桑,其菌根侵染率、AMF菌丝生物量以及镉含量都为0。接种AMF处理中,当Cd<5mg/kg时,桑苗菌根侵染率、AMF菌丝生物量、桑苗鲜生物量、枝叶中N、K、Ca、Mg以及根系N、K、Ca矿质元素的积累都有促进作用,在5mg/kg时促生效果最佳;当Cd>5mg/kg时,随着Cd浓度的升高,桑苗菌根侵染率、AMF菌丝生物量、桑苗鲜生物量、枝叶中N、K、Ca、Mg以及根系N、K、Ca矿质元素的积累都受到渐强的抑制;陷阱中Cd浓度高低与根系中Mg元素的吸收量之间显著负相关;接种AMF可以显著提高桑株生物量和矿质营养的积累;Cd主要集中在桑苗的根部,Cd处理浓度与AMF菌丝体中以及桑株中的Cd含量均显著正相关;Cd在菌根桑苗中的迁移率(<9%)和不同部位(根-茎、根-叶)的转移系数(<0.1)都极其低。结果证明:Cd胁迫对桑苗的菌根侵染率、营养生长、AMF菌丝生长和矿质吸收(除Mg外)都存在低促高抑的剂量效应;AMF对Cd胁迫有一定的抗性,接种AMF显著促进植物的生长以及矿质营养元素的吸收和转运;重金属Cd在菌根桑中的分布、迁移是不均匀的,具有一定的独特性。  相似文献   

5.
该研究以青杨雌雄幼苗为实验材料,采用盆栽控制实验的方式,设置20.5(CK)、50(T1)和100mg·kg-1(T2)3个铅浓度水平,分析面源水平铅污染条件下青杨性别间铅的积累和营养状况的差异。结果表明:(1)与CK相比,面源水平铅污染条件下,青杨雄株幼苗的总生物量未受到显著影响,雌株总生物量显著降低,但相同处理条件下雌株生物量均显著高于雄株。(2)2个梯度的铅污染均未显著影响两种性别青杨各器官中N的浓度,且雌雄间的性别差异不显著,但T2处理一定程度降低了两种性别各器官中P的浓度;与CK相比,雄株在受铅胁迫处理时N/P逐渐增加,说明此时雄株的生长可能会逐渐受到P素营养缺乏的影响。(3)随着铅处理浓度的增加,青杨雌株幼苗对铅的积累总量逐步增加,但雄株的积累总量的增加却不显著。可见,青杨雄株在面源水平铅污染条件下的抗性和耐受性优于雌株;雌雄青杨对土壤铅污染有不同的适应策略,雌株对铅的积累策略是其生物量下降以及营养平衡受到影响的主要原因,雄株对铅低吸收的策略使其更适应在铅污染区域生长。  相似文献   

6.
以濒危植物七子花二年生幼苗为研究材料,采用盆栽试验方法,研究干旱胁迫和接种丛枝菌根真菌(AMF)处理对幼苗不同器官C、N、P化学计量关系和非结构性碳水化合物(NSC)含量的影响。试验共设计4个处理:对照(CK)、干旱胁迫(D)、接种AMF(AMF)、干旱胁迫和接种AMF(D+AMF)。结果表明: 在干旱胁迫下七子花根系AMF的侵染率显著下降,但接种AMF处理植株的株高、叶片数显著高于未接种处理。接种AMF显著提高了干旱胁迫下植株根、叶可溶性糖和NSC含量及茎、叶淀粉含量,且茎和叶可溶性糖与淀粉比显著下降。干旱胁迫导致植株C含量在根和叶中显著增加,P含量在茎中显著减少;与干旱胁迫相比,胁迫下接种AMF植株根、茎、叶P含量及叶C含量显著提高,而根C、N含量及茎C含量显著降低。胁迫下接种AMF植株根、茎C∶N、C∶P、N∶P和叶N∶P均显著低于单一胁迫处理。NSC与C∶N∶P计量比的相关性分析表明,根、叶P含量与可溶性糖和NSC含量呈显著正相关,茎P含量与淀粉和NSC含量呈显著正相关,各器官N∶P与NSC含量呈显著负相关。综上,干旱胁迫显著抑制了七子花幼苗的生长,接种AMF通过提高植株根和叶的可溶性糖含量、根的可溶性糖/淀粉,增加地上部分淀粉含量,促进P元素吸收和降低各器官N∶P来增强植株耐旱性,从而提高七子花幼苗在干旱环境中的存活率。  相似文献   

7.
干旱胁迫条件下AMF促进小马鞍羊蹄甲幼苗生长的机理研究   总被引:1,自引:0,他引:1  
张亚敏  马克明  李芳兰  曲来叶 《生态学报》2016,36(11):3329-3337
采用温室水分控制试验,在干旱胁迫条件下,定量化研究优势丛枝菌根真菌(AMF)影响优势乡土植物小马鞍羊蹄甲(Bauhinia faberi var.microphylla)幼苗生长的机理,主要通过研究干旱胁迫条件下摩西球囊霉菌(Funneliformis mosseae)与小马鞍羊蹄甲的共生关系,阐明AMF在植物生长初期的作用。结果表明,干旱胁迫条件下,摩西球囊霉菌能够很好地侵染幼苗,侵染率高达89%—97%,并且不受水分条件影响。接种的幼苗最大光合速率、水分利用效率随着干旱胁迫程度从重度到轻度(水分从低到高)逐渐增大,相反地,叶片脯氨酸含量逐渐减小。接种显著地促进幼苗株高、叶片数、叶面积、根长、根面积等生长指标,提高幼苗各部分生物量、地上地下磷(P)含量。当含水量为60%田间持水量时,AMF促进小马鞍羊蹄甲幼苗吸收P的效果最好。接种还显著影响幼苗的生物量分配,在重度干旱胁迫时影响P分配,水分条件也显著影响幼苗的生物量分配。此外,接种和水分的交互作用对叶生物量、总生物量、生长指标以及地上部氮(N)总量影响显著。结果表明干旱胁迫条件下菌根效应显著,并在干旱条件下显著促进了小马鞍羊蹄甲幼苗的生长,这为进一步干旱河谷植被恢复提供了理论依据。  相似文献   

8.
本研究以大豆为材料,采用盆栽和田间试验,探讨丛枝菌根真菌(AMF)对豆科作物生长的影响。盆栽试验设置了接种(+AMF)和不接种(-AMF)丛枝菌根真菌处理,田间试验设置了AMF菌丝非限制与限制处理。盆栽试验结果表明: 接种AMF显著提高了大豆地上部生物量(16.5%)和大豆根瘤数(131.4%),地上部磷含量、磷吸收量、氮含量和氮吸收量也显著增加。田间试验中,AMF菌丝非限制处理下大豆的地上部生物量、根系生物量、根瘤数量分别比限制处理下显著提高了123.6%、61.5%和212.5%,地上部和根系磷吸收量、氮含量、氮吸收量均显著高于限制处理,大豆根际土壤速效氮和有效磷含量也均显著高于限制处理。本研究可为进一步认识豆科作物与AMF的共生关系及田间磷肥高效利用提供理论参考。  相似文献   

9.
为研究不同性别桑树在镉(Cd)与酸雨(AR)复合处理条件下的生长与镉积累差异,本试验以‘强桑1号’(雌株)和‘农桑14号’(雄株)两种不同性别桑树为材料,研究重金属镉(100 mg·kg-1干土)和模拟酸雨(pH 3.0)处理下,两者生物量积累和分配、最大净光合速率(Amax)和叶绿素荧光参数,以及Cd积累与分配的差异.试验共设置无Cd和AR(对照)、单独Cd、单独AR、Cd+AR复合4个处理.结果表明: 单独Cd处理虽然显著增加了雌株和雄株根茎叶中Cd含量,而且雌株各部分Cd含量显著高于雄株,但是只有雄株根、茎和总生物量、最大净光合速率显著下降,而雌株除了Amax显著下降外,各部分生物量积累下降均不显著,且两者的最大光化学效率(Fv/Fm)、光化学淬灭系数(qP)和非光化学淬灭系数(qN)均未发生显著变化.复合处理下,雄株和雌株的总生物量、Amax均显著降低,与单独镉处理相比,雌株根和叶中的Cd含量显著升高,但雄株没有明显变化,两者的Fv/Fm、qP没有显著变化,但qN均显著降低.短时间处理下桑树雌株对单独镉胁迫的耐受性高于雄株,但是酸雨的加入会降低雌株对镉的耐受性,可能是因为酸雨促进雌株根系对镉的吸收,并导致叶片积累了更多的镉.  相似文献   

10.
作者于塑料连栋大棚栽培条件下,研究了接种丛枝菌根真菌(AMF)Glomus mossea-2对低温下黄瓜(Cucumis sativus L.)幼苗同化产物积累、光合生理和过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)的活性及基因表达的影响。结果表明:低温显著抑制了AMF对黄瓜根系的侵染能力和菌根相对依赖性。接菌后30d—45d AMF为快速侵染期。接种AMF植株的鲜重根冠比、总干重、总鲜重均显著大于未接菌处理。低温胁迫下,接种AMF延缓了光合速率、根系活力、羧化效率和叶绿素、可溶性蛋白含量的下降,并且使丙二醛(MDA) 的含量保持相对较低的水平,诱导了抗氧化酶基因的表达及活性提高。接种AMF可以使叶片维持较高的抗氧化酶水平和光合能力,增强了对低温胁迫的抗性。 关键词:黄瓜;丛枝菌根真菌;低温;抗氧化酶  相似文献   

11.
The phylogeny of Old World monkeys has remained unresolved in part because of a lack of resolution in the Cercopithecinae. Competing morphological hypotheses have had Allen's swamp monkey (Allenopithecus nigroviridis) and the talapoins (Miopithecus spp.) as basal branches of either the tribe Cercopithecini or the tribe Papionini. Previous molecular analyses have not adequately addressed the issue. To better understand the evolutionary history of these primates, we sequenced and subjected to phylogenetic analysis 3.1 kb of 2 loci (TSPY and SRY) from the non-recombining portion of the Y-chromosome. Individuals from the genera Allenopithecus, Miopithecus, Erythrocebus, Chlorocebus, and Cercopithecus were surveyed and their sequences compared with those previously published for the Papionini and Colobinae. The results suggest Allenopithecus and Miopithecus are more closely related to the Cercopithecini than Papionini. Our data also support the hypothesis that within the Cercopithecini, Erythrocebus and Chlorocebus share a close evolutionary relationship, distinct from the other members of the tribe.  相似文献   

12.
The inhibitory effect of nystatin and killer toxin on the growth of free and covalently-immobilizedSaccharomyces cerevisiae cells was studied. The resistance of immobilized cells to both agents was accompanied by increased amounts of phospholipids and sterols. The possible relationship between these changes in the membrane composition and the transduction of a signal across the cytoplasmic membrane is discussed.  相似文献   

13.
The formation of different structures in Drosophila depends on the combined activities of selector genes and signaling pathways. For instance, the antenna requires the selector gene homothorax, which distinguishes between the leg and the antenna and can specify distal antenna if expressed ectopically. Similarly, the eye is formed by a group of "eye-specifying" genes, among them eyeless, which can direct eye development ectopically. We report here the characterization of the hernandez and fernandez genes, expressed in the antennal and eye primordia of the eye-antenna imaginal disc. The predicted proteins encoded by these two genes have 27% common amino acids and include a Pipsqueak domain. Reduced expression of either hernandez or fernandez mildly affects antenna and eye development, while the inactivation of both genes partially transforms distal antenna into leg. Ectopic expression of either of the two genes results in two different phenotypes: it can form distal antenna, activating genes like homothorax, spineless, and spalt, and it can promote eye development and activates eyeless. Reciprocally, eyeless can induce hernandez and fernandez expression, and homothorax and spineless can activate both hernandez and fernandez when ectopically expressed. The formation of eye by these genes seems to require Notch signaling, since the induction of ectopic eyes and the activation of eyeless by the hernandez gene are suppressed when the Notch function is compromised. Our results show that the hernandez and fernandez genes are required for antennal and eye development and are also able to specify eye or antenna ectopically.  相似文献   

14.
Aza- and deazaanalogues of adenosine, including their 1-protonated forms (except for that of 1-deazaadenosine), were studied by computer computation to find a relationship between their molecular structures and substrate properties for the mammalian adenosine deaminase. The atomic charge distribution and maps of the electrostatic potential around their van der Waals molecular surface were calculated for these compounds using the ab initio STO-3G method. The conformational studies are carried out by the MM+ method of molecular mechanics. The mechanism that determines the substrate selectivity of mammalian adenosine deaminase is discussed.  相似文献   

15.
Amplified ribosomal DNA restriction enzyme analysis (ARDRA), pulsed field gel electrophoresis (PFGE) and ribotyping were used to differentiate among 24 strains of Brevibacterium linens, Brevibacterium casei and Brevibacterium epidermidis obtained from type culture collections or isolated from various smear ripened cheeses. ARDRA was applied to the 16S rDNA. B. linens was shown to be a quite heterogenic group with 2 to at least 4 copies of rrn operons per strain with aberrant nucleotide sequences. AccI gave genus specific restriction patterns and was used to separate Brevibacterium from Corynebacterium species. The expected species specificity of TaqI applied to B. linens type culture strains, but not to all strains isolated from cheese. By AvaI restriction, B. casei and B. linens were differentiated from B. epidermidis and the orange pigmented Arthrobacter casei, a new species of coryneform bacteria; by XmnI restriction, B. linens and B. epidermidis were differentiated from B. casei. One of 4 B. linens genotypes could not be distinguished from B. casei by this method. Here, the typical orange B. linens pigments were used for classification, which was confirmed by partial sequencing of the 16S rDNA.  相似文献   

16.
Resin glycosides are secondary metabolites exclusive to the convolvulaceous plants. In this study, crypthophilic acids A–C (13), the first resin glycosides occurring in another family (Scrophulariaceae), and the other constituents of Scrophularia cryptophila were examined for in vitro antiprotozoal and antimycobacterial potentials. Except for crypthophilic acid B (2), all tested compounds exhibited growth-inhibitory effect against Trypanosoma brucei rhodesiense, with l-tryptophan (6) and buddlejasaponin III (7) being the most potent ones (IC50's 4.1 and 9.7 μg/ml). In contrast, the activity towards Trypanosoma cruzi was poor, and only crypthophilic acid C (3), 6 and 7 were trypanocidal at concentrations above 40 μg/ml. With the exception of 2 and 6, all compounds were active against Leishmania donovani. Harpagide (4) and 3 emerged as the best leishmanicidal agents (IC50's 2.0 and 5.8 μg/ml). Only compounds 3, 6 and 7 showed antimalarial activity against Plasmodium falciparum with IC50 values of 4.2, 16.6 and 22.4 μg/ml. Overall the best and broadest spectrum activity was presented by compounds 3 and 7, as they inhibited all four parasitic protozoa. None of the isolates had significant activity against Mycobacterium tuberculosis (MICs >100 μg/ml) or were toxic towards mammalian (L6) cells. This is the first report of antiprotozoal activity for natural resin glycosides, as well as for harpagide (4), acetylharpagide (5), tryptophan (6) and buddlejasaponin III (7).  相似文献   

17.
K. Schick  N. Toth 《Human Evolution》2000,15(1-2):121-128
Around two-and-a-half million years ago, some hominid populations in Africa began to modify stones and bones in a manner that can be recognized by prehistorians as artifacts, and, by definition, produced the earliest identifiable archaeological record. It is likely that earlier hominid groups also may have had relatively rich tool-using behavioral repertoires similar to that seen in modern chimpanzees (McGrew, 1992), such tools may have been made of perishable materials or minimally modified and thus difficult to identify. This review will focus on the earliest archaeological traces and the spread of hominids out of Africa and into Eurasia.  相似文献   

18.
Pericarp structure was investigated in 158 species of the familiesLamiaceae andVerbenaceae. Data from 221 out of 262 genera ofLamiaceae s.l. and a few ofVerbenaceae s.str. were collected in a table. A cladistic analysis was performed on the basis of pericarp characters only. The abandonment of subfam.Pogostemonoideae as a taxonomic unit is considered. Examples of groups given additional support by similarities in pericarp characters are: (1) the gynobasic-styled labiates (subfamiliesPogostemonoideae, Lamioideae, Nepetoideae); (2) aLamioideae-Pogostemonoideae-group; (3)Nepetoideae; (4) aWestringia-Hemigenia-Hemiandra-Microcorys group (in subfam.Chloranthoideae); (5) aLepechinia-Chaunostoma-group (inNepetoideae); (6) aPrunella-Cleonia-group (inNepetoideae).  相似文献   

19.
Effects of carbon concentration and carbon to nitrogen (C:N) ratio on six biocontrol fungal strains are reported in this paper. All fungal strains had extensive growth on the media supplemented with 6–12 g l−1 carbon and C:N ratios from 10:1 to 80:1, and differed in nutrient requirements for sporulation. Except for the two strains of Paecilomyces lilacinus, all selected fungi attained the highest spore yields at a C:N ratio of 160:1 when the carbon concentration was 12 g l−1 for Metarhizium anisopliae SQZ-1-21, 6 g l−1 for M. anisopliae RS-4-1 and Trichoderma viride TV-1, and 8 g l−1 for Lecanicillium lecanii CA-1-G. The optimal conditions for P. lilacinus sporulation were 8 g l−1 carbon with a C:N ratio of 10:1 for M-14 and 12 g l−1 carbon with a C:N ratio of 20:1 for IPC-P, respectively. The results indicated that the influence of carbon concentration and C:N ratio on fungal growth and sporulation is strain dependent; therefore, consideration for the complexity of nutrient requirements is essential for improving yields of fungal biocontrol agents.  相似文献   

20.
Spatial and temporal patterns of morel fruiting   总被引:2,自引:0,他引:2  
The biotic and abiotic factors conditioning morel fruit body production are incompletely known. We examined spatial and temporal patterns of Morchella esculenta fruiting over five years in a wooded site in Missouri, USA. Fruiting onset was inversely correlated with spring air and soil temperatures, whereas abundance was positively correlated with rain events (>10 mm) during the 30 d preceding fruiting. The two years with the greatest fruiting had the shortest fruiting seasons (6–7 d). Fruiting season length was positively correlated with soil warming, suggesting that a narrow range of optimum soil temperatures favour the explosive production of fruit bodies. All woody stems of at least 1 cm diam were mapped and stem diameter and crown condition were noted. Morel fruit bodies were significantly closer to stems of Carya spp., Tilia americana and Ulmus americana than predicted by the frequencies of these woody species or their contribution to the total basal area on the site. Although intra-annual clustering of fruit bodies was often observed, inter-annual clustering was not. The spatial pattern of M. esculenta fruiting appears to be associated with vegetation pattern, whereas the onset and abundance of fruiting are determined by the interaction of spring temperatures with availability of supporting precipitation.  相似文献   

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