NaCl处理对盐地碱蓬开花及Na~+、K~+含量的影响

为探讨盐地碱蓬(Suaeda salsa)开花与盐的关系,研究了1(对照)、200和400 mmol·L-1 NaCl处理对盐地碱蓬不同分枝和单株开花数目、叶片和茎及花器官中的Na+、K+含量及Na+/K+比的影响。结果表明:与对照相比,200 mmol·L-1 NaCl处理下盐地碱蓬分枝及单株开花数目增加最显著,单株开花数目增加了69.90%,花器官中的Na+含量、Na+/K+比分别增加了1.41倍和1.77倍,而一级叶片的Na+含量、Na+/K+比分别增加了3.96倍和4.96倍,茎中Na+含量、Na+/K+比分别增加了7.00倍和12.39倍。400 mmol·L-1 NaCl处理下,单株开花数目增加了19.00%,花器官中的Na+含量、Na+/K+比分别增加了2.09倍和3.21倍,而一级叶片的Na+含量、Na+/K+比分别增加了4.28倍和6.50倍,茎中Na+含量、Na+/K+比分别增加了7.65和15.40倍。这些结果表明,NaCl处理下真盐生植物盐地碱蓬可能通过把Na+区域化到茎叶而动员其中的K+到花器官中维持花器官中合适的Na+/K+比而促进开花。     

NaCl胁迫对醋栗番茄、樱桃番茄和番茄幼苗生长、叶片气体交换和离子平衡的影响

以醋栗番茄( Solanum pimpinellifolium Linn.)、樱桃番茄品种‘秦皇贵妃红’( S. lycopersicum var. cerasiforme‘Qinhuangguifeihong’)和番茄品种‘浙粉202’(S. lycopersicum‘Zhefen 202’)幼苗为材料,研究了0(对照)、100、200 mmol·L-1 NaCl胁迫对其生长、叶片气体交换参数和离子平衡的影响。结果表明：在100和200 mmol·L-1 NaCl胁迫下,‘秦皇贵妃红’和‘浙粉202’幼苗单株总干质量的降幅较大,醋栗番茄的降幅较小。 NaCl胁迫明显增加醋栗番茄幼苗的根冠比,但不同胁迫条件下‘秦皇贵妃红’和‘浙粉202’幼苗的根冠比差异不显著。与对照相比,在100 mmol·L-1 NaCl胁迫下,醋栗番茄幼苗叶片的净光合速率( Pn)、胞间CO2浓度( Ci)和蒸腾速率( Tr)的降幅明显低于‘秦皇贵妃红’和‘浙粉202’,而醋栗番茄幼苗叶片气孔导度(Gs)的降幅明显高于后二者;在200 mmol·L-1 NaCl胁迫下,三者叶片Pn、Gs、Ci和Tr值的降幅接近。在100和200 mmol·L-1 NaCl胁迫下,醋栗番茄、‘秦皇贵妃红’和‘浙粉202’幼苗叶片的水分利用效率和气孔限制值均较各自对照显著升高,其中‘秦皇贵妃红’的增幅最大。在100和200 mmol·L-1 NaCl胁迫下,醋栗番茄、‘秦皇贵妃红’和‘浙粉202’幼苗根、茎和叶中Na+含量均较各自对照显著升高,而K+含量和K+/Na+比总体上较各自对照显著降低。与对照相比,经不同浓度NaCl处理后醋栗番茄幼苗根、茎和叶的Na+含量增幅以及K+含量降幅在供试3种植物中均最小,而其不同部位的K+/ Na+比总体上较高。上述研究结果表明：醋栗番茄的耐盐性较强,‘秦皇贵妃红’次之,‘浙粉202’较弱。 NaCl胁迫显著抑制‘秦皇贵妃红’和‘浙粉202’幼苗根的生长,但显著促进醋栗番茄幼苗根的生长,使其维持较强的耐盐性,且NaCl胁迫下醋栗番茄对Na+的吸收和运输减少,以维持体内的离子平衡及较强的光合作用。     

NaCl胁迫对大米草光合·蒸腾等生理特性的影响

研究了NaCl胁迫下大米草净光合速率(Pn)、蒸腾速率(Tr),叶片气孔导度(Gs)、细胞问CO_2浓度(Ci)、株高、叶长、叶宽、茎粗、叶绿素含量、气孔限制值和水分利用效率.结果表明:当NaCl浓度高于300mmol/L时,大米草Pn、Tr、Gs、株高、叶长以及叶绿素含量受到显著抑制(P＜0.05),叶宽及茎粗则无显著性差异.NaCl胁迫下,大米革光合速率的降低是气孔因素和非气孔因素综合导致的结果,Pn、Tr、Gs、株高以及叶绿素含量的降低可作为大米草受NaCl胁迫的症状,而WUE则保持在较高的水平,因此在防治大米草蔓延时,排水处理不是最佳选择.     

NaCl胁迫对4种豆科树种幼苗生长和K~+、Na~+含量的影响

以合欢、刺槐、国槐和皂荚4种豆科树种盆栽实生幼苗为试验材料,研究了NaCl胁迫下4个树种幼苗的生长、耐盐临界浓度和Na+、K+含量的变化,并对其耐盐性进行了比较.结果表明:NaCl胁迫抑制了4个树种幼苗的生长,苗木的干物质积累量减小、根冠比增大,尤其对合欢和皂荚的影响较大;以相对干质量降至对照组50%时的NaCl浓度作为生长临界NaCl浓度(C50)指标,4个树种的耐盐强弱顺序为:刺槐(5.0‰)>国槐(4.5‰)>皂荚(3.9‰)>合欢(3.0‰);随NaCl浓度的增加,各树种幼苗根、茎、叶中Na+含量逐渐增加,K+含量先增加后减小(合欢根除外),而K+/Na+差异较大.相同浓度NaCl胁迫下,幼苗器官的Na+分布为根>茎>叶,K+因树种和NaCl浓度不同而各异,以叶片中较多,K+/Na+为叶>茎>根.NaCl胁迫下,刺槐的K+含量和K+/Na+较高,地上部分Na+含量较低,幼苗干物质量大,耐盐性较强;而合欢的K+/Na+较小,高浓度NaCl胁迫下地上部分的Na+含量较高,幼苗干物质量小,耐盐性较差.苗木地上部分对K+的积累和根部对Na+的滞留是影响豆科树种耐盐性能的主要因素.     

油菜素内酯对盐渍下油菜幼苗生长的调控效应及其生理机制

为了探讨油菜素内酯对植物耐盐性的调控,以甘蓝型油菜"南盐油1号"为试验材料,研究了外源24-表油菜素内酯(24-EBL)对100、200 mmol/L Na Cl胁迫下油菜幼苗干重(DW)、相对含水量(RWC)、渗透调节能力(OAA)、叶片气体交换参数、气孔限制值(Ls)等的调节效应,还测定了不同器官的Na+、K+、Cl-含量,并计算各器官的K+/Na+和SK,Na。结果表明:(1)在不同浓度的盐胁迫下,油菜幼苗DW显著下降,胁迫下外源喷施10-12、10-10、10-8、10-6mol/L 24-EBL作用下,油菜植株干重均不同程度的上升,且植株干重都在10-10mol/L 24-EBL(EBL2)处理下达到最大值,分别比100、200 mmol/L Na Cl胁迫下增加29%和20%。与对照相比,非盐胁迫下外源喷施10-12、10-10、10-8、10-6mol/L 24-EBL,油菜幼苗植株干重与对照相比均无显著变化。(2)不同Na Cl浓度胁迫下,油菜叶片的RWC显著下降,外施EBL2可显著提高油菜叶片的RWC和OAA。(3)不同浓度Na Cl胁迫下,油菜幼苗叶片净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)均不同程度下降,而Ls显著上升,而外喷EBL2可不同程度的提高Pn、Gs、Ci、Tr,降低Ls。(4)与对照相比,Na Cl胁迫下油菜幼苗叶片、叶柄和根的Na+和Cl-含量均显著上升,Na Cl浓度愈高,Na+和Cl-含量上升愈显著。而K+含量均下降,外源EBL2可显著降低幼苗各器官的Na+和Cl-含量,对幼苗叶片K+含量没有影响,但提高了叶柄和根中的K+含量。上述表明,合适浓度的24-EBL外喷可明显提高油菜的耐盐水平,且不同浓度Na Cl胁迫下,最适24-EBL浓度均为10-10mol/L。主要是因为外源喷施24-EBL能显著改善离子稳态和渗透调节能力,从而改善盐胁迫下油菜幼苗的光合作用、水分状况,提高其耐盐性。而24-EBL对盐处理下油菜植株气孔限制的显著改善是其促进其光合、水分利用的重要原因,也是其对100 mmol/L Na Cl处理的油菜生长调控效果优于200 mmol/L Na Cl处理的重要原因之一。结果还显示,在叶片中,24-EBL外施可通过排Na+和Cl-来维持植株离子稳态,而对K+影响不大;在根、茎中可通过排Na+、排Cl-、吸K+维持稳态。     

外源SA和NO对NaCl胁迫下番茄幼苗生长、光合及离子分布的影响

以番茄(Lycopersicon esculentum Mill.)品种‘秦丰保冠’为试材,采用营养液培养法,研究单独和复配施用外源水杨酸(SA)、一氧化氮(NO)供体硝普钠(SNP)对100mmol/L NaCl胁迫下番茄幼苗生长、光合及离子分布的影响。结果表明:(1)单独和复配外施SA、SNP均能有效抑制NaCl胁迫下番茄幼苗叶片光合色素(Chla、Chlb、Chla+b和Car)含量、Chla/b值、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、瞬时水分利用效率(WUEt)、表观光能利用效率(LUEapp)和表观CO2利用效率(CUEapp)的下降及Car/Chla+b值和胞间CO2浓度(Ci)的升高,并以SA和SNP复配处理效果最明显。(2)NaCl胁迫下,外源SA、SNP单独和复配处理的番茄幼苗各器官(叶、茎和根)中Cl-、Na+含量和Na+/K+、Na+/Ca2+、Na+/Mg2+值显著降低,而K+、Ca2+和Mg2+的含量却不同程度提高,其中以SA和SNP复配处理效果最好。(3)单独和复配外施SA、SNP均能有效减轻NaCl胁迫对番茄幼苗生长的抑制作用,并促进各器官生物量的积累和壮苗的形成,且以SA和SNP复配处理效果更佳。研究表明,复配外施SA和SNP在诱导番茄幼苗提高抗(耐)盐能力方面具有协同增效作用。     

NaCl胁迫对菊芋幼苗生长和叶片光合作用参数以及体内离子分布的影响

对不同浓度[0(CK)、50和100 mmol·L-1]NaCl胁迫条件下菊芋(Helianthus tuberosus L. )幼苗的生长、叶片光合作用参数以及体内Cl-、Na+和K+含量分布状况进行了比较研究.结果表明,随NaCl浓度的提高,菊芋幼苗单株地上部分的鲜质量和干质量以及全株鲜质量和干质量均逐渐下降且均与对照差异显著(P<0.05);地下部分的鲜质量和干质量也呈逐渐下降的趋势,但仅100 mmol·L-1NaCl处理组与对照组间有显著差异(P<0.05).随NaCl浓度的提高,叶片的净光合速率(Pn)和气孔导度(Gs)逐渐减小、水分利用效率(WUE)和气孔限制值(Ls)逐渐增大,但总体上差异不显著(P>0.05);50和100 mmol·L-1NaCl处理组的Pn分别为对照组的85.6%和44.9%,Gs分别为对照组的67.9%和57.1%,WUE分别为对照组的1.25和1.54倍,Ls分别为对照组的1.57和1.64倍.随NaCl浓度的提高,菊芋幼苗地上部分和地下部分的Cl-和Na+含量逐渐增加、K+含量逐渐减小,且各处理组间Na+含量差异显著、K+含量差异不显著;地上部分和地下部分的Na+/K+比均随NaCl浓度的提高逐渐增大,0、50和100 mmol·L-1NaCl处理组幼苗地上部分的Na+/K+比分别为0.26、0.83和2.39,地下部分的Na+/K+比分别为0.51、1.16和2.83;各处理组幼苗地上部分的Cl-、Na+和K+含量均明显高于地下部分,表明地下部分吸收的Cl-、Na+和K+大部分被转移至地上部分.研究结果显示,NaCl胁迫对菊芋幼苗生长和叶片光合作用等均有一定的抑制作用,对其体内离子平衡也有一定的影响,干扰了菊芋幼苗的正常生长.     

NaCl胁迫对阿月浑子各器官Na+、K+吸收的影响

在温室盆栽条件下,用NaCl处理新疆长果阿月浑子与美国品种Kerman,处理浓度为50、150、250和500 mmol·L-1,盐处理后5、10、20 d分别取叶、茎和根,测定各器官中Na+、K+含量及Na+/K+变化规律.研究结果表明,随着土壤盐浓度的增加,长果阿月浑子和Kerman的叶、茎和根中Na+离子含量在盐处理5、10、20 d后每个处理都表现出升高趋势;而两个品种的叶、根和茎中的K+含量在盐处理后其变化规律都不稳定.长果阿月浑子叶片、茎和根系中Na+/K+的比值在盐处理5 d和10 d都升高.Kerman的叶和根系中Na+/K+比值在处理5、10、20 d后升高;茎中Na+/K+处理10 d后升高,但20 d后没有明显变化.实验结果表明NaCl胁迫后,长果阿月浑子的叶片中Na+含量增加幅度均大于Kerman,Kerman根和茎中的Na+含量增加幅度大于长果阿月浑子;NaCl胁迫5 d和10 d后,长果阿月浑子叶片中的Na+/K+的比值高于Kerman,Kerman茎和根部中的Na+/K+的比值高于长果阿月浑子,表明了长果阿月浑子和Kerman都具有一定的耐盐性,但Kerman的耐盐性强于长果阿月浑子.由于叶片和根中Na+和Na+/K+比值的变化很稳定,可以确定为阿月浑子主要抗盐指标,茎中Na+/K+的变化规律较稳定,可以作为抗盐性参考指标.     

NaCl胁迫对大米草光合·蒸腾等生理特性的影响

研究了NaCl胁迫下大米草净光合速率（Pn）、蒸腾速率（Tr）,叶片气孔导度（Gs）、细胞间CO2浓度（Ci）、株高、叶长、叶宽、茎粗、叶绿素含量、气孔限制值和水分利用效率。结果表明：当NaCl浓度高于300mmol／L时,大米草Pn、Tr、Gs、株高、叶长以及叶绿素含量受到显著抑制（P〈0．05）,叶宽及茎粗则无显著性差异。NaCl胁迫下,大米草光合速率的降低是气孔因素和非气孔因素综合导致的结果,Pn、Tr、Gs、株高以及叶绿素含量的降低可作为大米草受NaCl胁迫的症状．而WUE则保持在较高的水平．因此在防治大米草荨延时．排水处理不是最佳选择。     

氯化钾对长春花盛花期盐胁迫效应和生物碱含量的影响

在温室土培条件下,研究了不同浓度KCl处理对长春花盛花期盐胁迫效应以及对文多灵、长春质碱、长春碱和长春新碱等生物碱含量的影响.结果现实:(1)3‰ NaCl胁迫下,施入一定量KCl,将Na+/K+调为20:1(K2)时可显著缓解盐胁迫对长春花的危害,与不施KCl(K1)相比,长春花的鲜质量、株高、根长和相对含水量均显著提高,而长春花叶片丙二醛含量显著下降,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性在Na+/K+为20:1(K2)时显著高于其它处理,但当Na+/K+为10:1(K3)与5:1(K4)时,盐胁迫的危害又显著加剧.(2)Na+/K+为20:1处理的长春花盛花期文多灵、长春质碱、长春碱和长春新碱含量显著高于其它处理,分别为20.88、30.18、2.53和5.12 mg·g-1.研究表明,Na+/K+为20:1比例施用钾肥可最大限度地降低NaCl胁迫对盛花期长春花生长造成的伤害,并显著促进其生物碱的代谢,显著提高长春花盛花期4种主要生物碱的含量.     

Plant-Parasitic Nematodes of South Viet Nam

Between 1974 and 1978, 2,842 identifications of plant-parasitic nematodes were made from more than 1,700 soil and plant samples collected in eight provinces of South Viet Nam. Species in nine genera—Helicotylenchus, Criconemoides, Meloidogyne, Pratylenchus, Tylenchorhynchus, Hoplolaimus, Hirschmanniella, Xiphinema, and Rotylenchulus—comprised 96.1% of the identifications; the remaining 3.9% were species of 11 genera. Fourteen genera were associated with rice which was grown on about 2,500,000 ha in 1970. Of these, Ditylenchus, Hirschmanniella, and Meloidogyne were most important. Ditylenchus angustus caused severe damage to about 50,000 ha of flooded rice in the Mekong Delta in 1976. Hirschmanniella spp. were found in all samples examined from flooded rice fields. Meloidogyne spp. were common in rice seedbeds, upland rice, and rice not kept flooded continuously. Meloidogyne and Pratylenchus spp. were found in roots of 22 of the 32 crop plants sampled. Little or no attempt was made in South Viet Nam to control nematodes.     

Identification key for European strand-forming house-rot fungi

An identification key for 20 common strand-forming indoor wood decay fungi is given. The key is based on observations of material from affected buildings and on wood samples that have been incubated in the laboratory. The key is with macro- and microscopic photographs.     

Semicircular canal system in early primates

Mammals with more rapid and agile locomotion have larger semicircular canals relative to body mass than species that move more slowly. Measurements of semicircular canals in extant mammals with known locomotor behaviours can provide a basis for testing hypotheses about locomotion in fossil primates that is independent of postcranial remains, and a means of reconstructing locomotor behaviour in species known only from cranial material. Semicircular canal radii were measured using ultra high resolution X-ray CT data for 9 stem primates (“plesiadapiforms”; n = 11), 7 adapoids (n = 12), 4 omomyoids (n = 5), and the possible omomyoid Rooneyia viejaensis (n = 1). These were compared with a modern sample (210 species including 91 primates) with known locomotor behaviours. The predicted locomotor agilities for extinct primates generally follow expectations based on known postcrania for those taxa. “Plesiadapiforms” and adapids have relatively small semicircular canals, suggesting they practiced less agile locomotion than other fossil primates in the sample, which is consistent with reconstructions of them as less specialized for leaping. The derived notharctid adapoids (excluding Cantius) and all omomyoids sampled have relatively larger semicircular canals, suggesting that they were more agile, with Microchoerus in particular being reconstructed as having had very jerky locomotion with relatively high magnitude accelerations of the head. Rooneyia viejaensis is reconstructed as having been similarly agile to omomyids and derived notharctid adapoids, which suggests that when postcranial material is found for this species it will exhibit features for some leaping behaviour, or for a locomotor mode requiring a similar degree of agility.     

Two common and problematic leucochrysine species – Leucochrysa (Leucochrysa) varia (Schneider) and L. (L.) pretiosa (Banks) (Neuroptera,Chrysopidae): redescriptions and synonymies

We dedicate this article to the memory of Sergio de Freitas, FCAV-UNESP, Jaboticabal, São Paulo, Brazil (deceased, 2012). He was an active and enthusiastic Neuropterist and the cherished mentor and friend of Francisco Sosa.Leucochrysa McLachlan is the largest genus in the Chrysopidae, yet it has received relatively little taxonomic attention. We treat two problematic and common Leucochrysa species – Leucochrysa (Leucochrysa) varia (Schneider, 1851) and Leucochrysa (Leucochrysa) pretiosa (Banks, 1910). Both are highly variable in coloration and were described before the systematic importance of chrysopid genitalia was recognized. Recent studies show that these species occur within a large complex of cryptic species and that they have accumulated a number of taxonomic problems. We identify new synonymies for each of the species–for Leucochrysa (Leucochrysa) varia: Leucochrysa (Leucochrysa) ampla (Walker, 1853), Leucochrysa internata (Walker, 1853), and Leucochrysa (Leucochrysa) walkerina Navás, 1913; for Leucochrysa (Leucochrysa) pretiosa: Leucochrysa (Leucochrysa) erminea Banks, 1946. The synonymy of Leucochrysa delicata Navás, 1925 with Leucochrysa (Leucochrysa) pretiosa is stabilized by the designation of a neotype. The following species, which were previously synonymized with Leucochrysa (Leucochrysa) varia or Leucochrysa (Leucochrysa) pretiosa, are reinstated as valid: Leucochrysa (Leucochrysa) phaeocephala Navás, 1929, Leucochrysa (Leucochrysa) angrandi (Navás, 1911), and Leucochrysa (Leucochrysa) variata (Navás, 1913). To help stabilize Leucochrysa taxonomy, lectotypes are designated for Allochrysa pretiosa and Allochrysa variata. Finally, Leucochrysa vegana Navás, 1917 is considered a nomen dubium.     

Multilocus phylogenetic analysis of the genus Aeromonas

A broad multilocus phylogenetic analysis (MLPA) of the representative diversity of a genus offers the opportunity to incorporate concatenated inter-species phylogenies into bacterial systematics. Recent analyses based on single housekeeping genes have provided coherent phylogenies of Aeromonas. However, to date, a multi-gene phylogenetic analysis has never been tackled. In the present study, the intra- and inter-species phylogenetic relationships of 115 strains representing all Aeromonas species described to date were investigated by MLPA. The study included the independent analysis of seven single gene fragments (gyrB, rpoD, recA, dnaJ, gyrA, dnaX, and atpD), and the tree resulting from the concatenated 4705 bp sequence. The phylogenies obtained were consistent with each other, and clustering agreed with the Aeromonas taxonomy recognized to date. The highest clustering robustness was found for the concatenated tree (i.e. all Aeromonas species split into 100% bootstrap clusters). Both possible chronometric distortions and poor resolution encountered when using single-gene analysis were buffered in the concatenated MLPA tree. However, reliable phylogenetic species delineation required an MLPA including several “bona fide” strains representing all described species.     

Bacterial flora in the alimentary tract of chickens infected with Eimeria brunetti and in chickens immunized with Eimeria maxima and cross-infected with Eimeria brunetti

Differential bacterial counts were made on the intestinal and caecal contents of chickens after inoculation with a standard dose of 320 000 freshly sporulated oocysts of Eimeria brunetti.