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1.
中华水韭叶舌和缘膜的发生及其发育进程研究   总被引:1,自引:0,他引:1  
采用石蜡切片技术,以人工培养的中华水韭幼苗的最初几枚叶至成熟植株的叶为实验材料,连续解剖观察其叶舌和缘膜的发生、发育进程,并分析其发育进程与孢子囊和叶片的关系.结果显示:(1)中华水韭叶舌与叶片在其个体发育早期来自于同一原基,但叶舌最初的发育速度快于叶片.(2)中华水韭的苗龄达到15枚叶时开始有孢子囊发生,此时的叶舌下方有明显的缘膜结构.(3)当中华水韭的孢子体达到30枚叶片以上时,早期产生于植株外围的孢子囊已经发育成熟,可以清楚地区分出大、小孢子囊,其中在已经成熟的大孢子叶上,叶舌相对于孢子囊的长度变短,下唇萎缩,缘膜消失;成熟小孢子叶的叶舌比大孢子叶的叶舌长,上翻程度大,下唇萎缩程度不如大孢子叶明显,缘膜也退化消失.研究认为,缘膜是水韭系统发育早期的普遍结构,而演化后期一些地区的缘膜则显著退化甚至消失;对于系统发育初期的中华水韭,其叶舌与叶片的差异并不像现代水韭那么明显.  相似文献   

2.
低温胁迫对极度濒危植物中华水韭生理特性的影响   总被引:1,自引:0,他引:1  
刘婷婷  孙昊  关旸  刘保东 《西北植物学报》2013,33(10):2031-2036
以人工繁殖的极度濒危级(CR)植物中华水韭(Isoetes sinensis Palmer)为试验材料,研究了0 ℃低温环境下胁迫0~20 d,沉水叶片中保护酶系统(POD、SOD、CAT)、渗透调节物质(可溶性糖和可溶性蛋白)、叶绿素以及丙二醛(MDA)和相对电导率的变化。结果显示:随着低温(0 ℃)胁迫时间的延长,中华水韭沉水叶片的相对电导率、可溶性糖含量、CAT活性先升高后下降,SOD活性呈逐渐上升的趋势,POD活性、可溶性蛋白含量、叶绿素含量下降,MDA含量一直低于CK,且在一定范围内波动。研究表明,中华水韭沉水叶片在0 ℃低温胁迫中受到一定程度的伤害,但能通过调节自身的膜透性、渗透调节物质含量和保护酶活性系统来减轻低温伤害,维持其正常生理代谢功能,从而表现出一定的抗寒潜力。  相似文献   

3.
采用水培法,研究了不同营养条件对中华水韭叶片生理生化特性和光合荧光特性的影响。结果显示:随着营养液中氮、磷浓度的升高,中华水韭叶片的生理生化特性除叶绿素含量呈下降的变化趋势外,可溶性糖、丙二醛、脯氨酸含量、过氧化氢酶活性(CAT)均呈上升趋势,而过氧化物酶活性(POD)则呈先上升后下降的趋势;同时叶片光合荧光特性中除非光化学猝灭系数(qN)呈上升的趋势外,PSⅡ的最大量子产量(Fv/Fm)、有效量子产量(Yield)、光化学猝灭系数(qP)、最大潜在相对电子传递速率(Pm)以及快速光响应曲线初始斜率(α)和半饱和光强(Ik)均呈下降的趋势。研究表明,随着水体氮、磷浓度的升高,中华水韭在中度营养条件下(N 0.4mg·L~(-1)、P0.04mg·L~(-1))耐受性较好,但在高营养条件下(N 1.2mg·L~(-1)、P 0.12mg·L~(-1))耐受性较差,其渗透调节能力和抗氧化能力上升,但光合作用能力下降,抑制了中华水韭的正常光合生理活动,进而影响其生长,推测水体富营养化可能是造成中华水韭濒危的重要原因之一。  相似文献   

4.
不同反光膜对设施葡萄光合特性和叶片糖代谢的影响   总被引:1,自引:0,他引:1  
以‘京秀’葡萄为试材,研究了蓝膜、红膜、铝膜3种反光膜对设施葡萄光合特性和叶片糖代谢的影响。结果显示:红膜和蓝膜处理的葡萄叶片的净光合速率均显著高于对照(不铺设反光膜);在果实发育前期,各处理的叶绿素含量和叶绿素b/a值均大于对照,而后期均低于对照;蓝膜和红膜处理叶片的蔗糖含量较高,而蓝膜处理叶片中的蔗糖合酶(SS)和蔗糖磷酸合酶(SPS)活性最高;各铺膜处理均比对照提高了葡萄果实鲜量和可溶性糖含量、降低可滴定酸含量,且蓝膜处理显著优于红膜和铝膜。研究表明,在设施栽培条件下,地面铺设蓝色反光膜可显著提高葡萄叶片的光合速率和叶片中碳水化合物的关键合成酶活性,并显著提高葡萄果实品质。  相似文献   

5.
【目的】探讨绿盲蝽Apolygus lucorum(Meyer-Dür)为害对枣树叶片光合作用的影响及其机制。【方法】以一年生冬枣Zizyphus jujuba cv.Dongzao和酸枣Ziziphus jujuba var.spinosa树叶片为试材,测定了绿盲蝽为害1,3,5和7 d时枣树叶片光合速率、气体交换、叶绿素荧光参数和叶绿素含量的变化。【结果】绿盲蝽为害3,5和7 d时冬枣叶片的净光合速率(net photosynthesis rate,Pn)较对照分别降低了55.83%,55.42%和59.61%;而酸枣叶片净光合速率仅在5和7 d时较对照分别降低了26.66%和27.34%。冬枣叶片的气孔导度被绿盲蝽为害3,5和7 d时较对照明显降低。冬枣叶片光合速率的下降与气孔导度(stomatal conductance,Gs)和总叶绿素含量的下降呈显著正相关,而酸枣叶片光合速率的下降仅与叶绿素含量显著正相关。绿盲蝽为害后冬枣和酸枣叶片的快速荧光诱导曲线受到显著影响。冬枣叶片的最大光化学效率(maximum photochemical efficiency,Fv/Fm)在绿盲蝽为害不同时间时相对于对照明显降低,而酸枣叶片没有受到明显的影响。绿盲蝽为害不同时间对冬枣和酸枣叶片的光系统Ⅱ放氧复合体(oxygen-evolving complex,OEC)以及光反应活性中心均造成了伤害,但酸枣受到的伤害程度明显低于冬枣。绿盲蝽为害5和7 d后冬枣叶片的光系统Ⅱ的电子传递活性降低,而酸枣叶片光系统Ⅱ的电子传递活性没有受到显著影响。绿盲蝽为害导致冬枣和酸枣叶片的电子传递的量子产额较对照明显降低,酸枣叶片中的降低幅度低于冬枣。【结论】绿盲蝽为害造成枣树叶片净光合速率明显降低,不同品种存在明显差异,冬枣叶片Pn降低程度明显高于酸枣。绿盲蝽为害后枣树叶片净光合速率的下降与叶绿素含量降低呈显著正相关。绿盲蝽为害影响了枣树叶片PSⅡ的结构和功能,导致供体侧的OEC受到伤害,光合作用PSⅡ反应中心失活,PSⅡ反应中心关闭程度增加,电子传递活性受到了抑制,其中酸枣叶片PSⅡ受到的影响明显低于冬枣叶片。  相似文献   

6.
Na+吸收对干旱导致的棉花叶片光合系统损伤的缓解作用   总被引:1,自引:0,他引:1  
解卫海  马淑杰  祁琳  张振华  柏新富 《生态学报》2015,35(19):6549-6556
以盆栽棉花为材料,在植株高约20 cm时用不同浓度Na Cl溶液浇透后进行持续干旱处理。在干旱处理期间测定叶片叶绿素荧光参数、光合气体交换参数的变化以及植株水分状况和Na+含量,以分析土壤Na Cl施入引起的棉花Na+吸收和积累量的增加对干旱胁迫导致的叶片光合系统损伤的缓解作用及可能原因。结果表明,未用Na Cl处理的棉花植株,其叶片净光合速率随着干旱的延续而持续下降、光合机构在干旱处理后期出现了严重损伤;而Na Cl处理的棉花植株,其叶片净光合速率下降幅度明显小于未用Na Cl处理的,光合机构受损伤程度也较轻或无明显损伤。对各处理棉花植株Na+的吸收和水分状况的测定分析表明,Na Cl处理的植株,其叶片Na+积累显著增加、渗透势降低,细胞膨压显著高于未用Na Cl处理的植株。由此可见,在土壤浇灌Na Cl溶液后的持续干旱条件下,棉花植株吸收和积累Na+增加,降低了组织渗透势、维持了一定的细胞膨压,从而有效缓解了干旱胁迫对叶片光合机构的损伤。  相似文献   

7.
N^+注入对紫薇光合特性和叶绿素含量的影响   总被引:1,自引:0,他引:1  
采用离子注入诱变育种技术对紫薇种子进行处理,正常播种后测两年生植株叶片的光合特性和叶绿素含量,结果表明:与对照相比,经离子注入处理后,各处理的净光合速率都有不同程度的增加,光合速率饱和时所需要的光合有效辐射均较未注入处理的低。叶绿素a和b的绝对含量呈现双峰型变化趋势,但叶绿素a的增加量受注入剂量的影响较大,叶绿素a/b比值变化不明显,离子注入处理能提高紫薇幼苗的潜在光合能力和耐荫性。  相似文献   

8.
采用盆栽试验,添加不同浓度(0、200、400 mg·kg~(-1))铜(Cu),研究接种丛枝菌根真菌(AMF)摩西球囊霉(Glomus mosseae)对白术(Atractylodes macrocephala)幼苗生长、光合特性、膜脂过氧化程度及抗氧化酶活性的影响。结果表明:与对照相比,Cu胁迫使白术幼苗生长和叶片光合系统受到明显抑制,膜脂过氧化水平升高,抗氧化酶活性降低;接种摩西球囊霉后发现其能够较好地侵染白术根系,接种摩西球囊霉的白术幼苗在不同浓度Cu胁迫下,均表现为叶片叶绿素a、叶绿素b和总叶绿素含量增加,叶片净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)显著升高,胞间CO_2浓度(C_i)显著下降,质膜相对透性(MRP)及膜脂过氧化产物丙二醛(MDA)含量显著降低;超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性较对照显著增加,植株生长量和体内Cu积累量较对照均有所下降。以上结果说明接种摩西球囊霉可提高Cu胁迫下白术幼苗叶片光合能力和抗氧化能力,降低膜脂过氧化水平,减少白术根系对Cu的吸收,缓解Cu胁迫对白术植株的伤害,提高白术产量和品质。  相似文献   

9.
以东方百合‘Sorbonne’为材料,在持续干旱4、8、12、16、20、24d及干旱24d后复水4d时分别取样,检测叶片叶绿素荧光参数、光合生理指标、抗氧化酶活性和丙二醛含量,并观测其茎生根发育情况以及调查植株在干旱胁迫期、复水期、开花期的花粉育性,明确干旱胁迫对百合根、叶生理功能及花粉育性的影响,探讨百合的抗旱生理机制。结果表明:(1)与对照相比,干旱处理组百合植株的叶绿素含量随着干旱时间延长而逐渐降低,处理4d后百合开始明显受到干旱胁迫;胁迫4~8d内,光合作用受到的胁迫主要是气孔因素所致;胁迫8~12d期间,叶片荧光叶绿素指标开始急剧变化,光合作用受到的胁迫已开始从气孔因素转变为非气孔因素;胁迫12d后,叶片丙二醛含量增加,膜质开始受到氧化;胁迫16d时,叶片抗氧化酶系统活性达到峰值,随后开始降低,丙二醛累积随之增加,膜脂过氧化作用加剧;胁迫24d时,叶片光合指标略有所恢复。(2)解除干旱胁迫复水4d后,百合叶片光合生理指标均有所恢复,但未恢复到胁迫前水平。(3)与正常对照相比,经历干旱胁迫的百合根系随着干旱胁迫时间的延长先缩短变粗、数量减少,然后逐渐褐化并趋近萎缩,且根系干鲜重显著降低,但花粉育性在胁迫期、复水期及开花期没有显著变化。研究发现:持续24d的干旱胁迫会对东方百合叶片的光合功能和抗氧化酶系统以及根系产生破坏性的伤害,但对花粉的育性没有影响。  相似文献   

10.
以耐旱性较强的德国景天(Sedum hybridum)扦插苗为材料进行干旱胁迫处理(60d),并测定其叶片相对含水量、丙二醛含量、细胞伤害率、光合参数(净光合速率、气孔导度、蒸腾速率)、荧光参数(F_v/F_m、q~P、PHiPS2),以及苹果酸含量、磷酸烯醇式丙酮酸羧化酶(PEPCase)活性等生理指标。结果显示,干旱胁迫导致德国景天叶片相对含水量、光合参数、荧光参数降低,细胞伤害率、丙二醛含量升高;干旱胁迫30d时,各项生理指标变化幅度较小,但40d后变化幅度显著增加,并且德国景天叶片的苹果酸含量和PEPCase活性显著升高,表明C_3光合途径不断减弱,景天酸代谢(CAM)途径被激活,参与了德国景天对干旱胁迫的响应,提高了其耐旱性;当干旱胁迫达60d时,因超过其耐受范围,德国景天受损严重,逐渐死亡。这说明德国景天在生理上表现出极强的耐旱性,并且具有兼性CAM植物的特征,通过CAM途径活化提高植株耐旱性是德国景天重要的耐旱机理。  相似文献   

11.
Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.  相似文献   

12.
The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.  相似文献   

13.
Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.  相似文献   

14.
A molecular phylogeny of Hebeloma species from Europe   总被引:2,自引:1,他引:1  
In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.  相似文献   

15.
Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.  相似文献   

16.
Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr−1) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.  相似文献   

17.
The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.
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20.
Systematic significance of mature embryo of bamboos   总被引:1,自引:0,他引:1  
The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.  相似文献   

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