氮素水平对不同品种茶树光合及叶绿素荧光特性的影响

为探明氮素水平对不同品种茶树的光合系统的影响机制,以‘福鼎大白茶’、‘保靖黄金茶1号’、‘白毫早’两年生茶苗为材料,设置不施氮N_0(0g)、低氮N_1(11g)、中氮N_2(22g)和高氮N_3(33g)4个氮素[(NH_4)_2SO_4]水平的盆栽实验,研究了铵态氮对3个品种茶树的生长势、叶片叶绿素含量、光合参数与叶绿素荧光参数的影响。结果表明:(1)施氮处理能够显著促进茶树的生长,提高茶树叶片叶绿素含量、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr),降低胞间CO_2浓度(Ci),并以N_2处理最好,但水分利用率(WUE)在3个品种茶树间表现不同。(2)在N_2处理下,3个茶树品种的叶片光系统Ⅱ(PSⅡ)暗适应下的最大光化学效率(F_v/F_m)、光化学猝灭系数(qP)、PSⅡ的相对电子传递速率(rETR)亦增加最大,非光化学淬灭系数(NPQ)降低。(3)茶树叶片叶绿素含量与光合参数间存在着一定的联系,并且具有品种特异性。研究发现,适量施氮能够显著增加茶树叶绿素含量、气孔导度、光合活性,从而使得各品种茶树净光合速率增加;氮素水平对各茶树品种的光合及荧光特性影响存在差异,水分利用率亦具有品种特异性;生产中应综合叶绿素含量、光合作用参数、叶绿素荧光参数,可快速、直观地评价不同品种茶树对氮素营养的内在需求,为茶园施肥管理提供指导。     

浙江省茶树春霜冻害气象指标的修订

修订茶树霜冻害气象指标对于科学客观地开展春季茶树霜冻灾害的监测预警和影响评估具有重要意义。本文以浙江省茶树4个主栽品种为材料,应用人工气候箱开展低温胁迫控制试验,模拟6组不同低温条件和持续时间(15℃/3℃、12℃/2℃、10℃/1℃、10℃/0℃、10℃/-1℃、10℃/-2℃,各设置组较高温度持续12 h,较低温度持续4 h;对照温度25℃),观测茶树叶片生理生化指标的变化,应用Logistic函数确定茶树的半致死温度。结果表明:茶树霜冻害的发生与低温强度和持续时间密切相关,各品种茶树叶片半致死温度为福鼎大白茶(-1.5℃)乌牛早(-1.3℃)鸠坑(-1.2℃)龙井43(-0.7℃);结合历史灾情和茶园逐小时气温观测数据,提出了新的茶树春霜冻害等级标准,包括气象指标、茶树受灾症状和新梢芽叶受害率,其中气象指标为新梢生长期间每日的小时最低气温和持续小时数。应用2013年春季2次霜冻灾害验证,新标准的监测结果与实际情况基本吻合,并且比原有标准吻合率提高41.7%。研究成果可为茶叶气象定量化服务提供重要的技术支持。     

光照和氮营养对水曲柳苗木光合特性的影响

采用室内沙培方式,设计不同光强(2水平)和N浓度(4水平)处理,探讨1年生水曲柳幼苗叶片光合速率和荧光参数对环境变化的生理响应.结果表明:与全光照相比,遮光处理使苗木叶片最大光合速率(Amax)、光补偿点(LCP)以及光化学猝灭系数(qP)明显下降,但使表观量子效率(AQY)、最大荧光(Fm)和最大光化学效率(Fv/Fm)明显增加.同时,苗木叶片单位面积的叶绿素a、类胡萝卜素、总叶绿素含量以及叶绿素a/b在遮光条件下较低.2种光强下的Fm、Fv/Fm、ψpsⅡ和qP均随着供N浓度的增加而显著增加(P＜0.05),其中ψpsⅡ在低N时增加较快而高N时较慢,甚至略有下降.光强和N浓度在水曲柳苗木叶片Fm、ψpsⅡ、Fv/Fm、qN以及qP上均具有显著的交互作用(P＜0.05).     

17个建兰品种光合特性分析

以17个建兰(Cymbidium ensifolium)品种为材料,采用改良的丙酮法提取叶绿素,再通过Arnon丙酮法公式计算光合色素含量,利用捷克FluorCam开放式叶绿素荧光仪测定不同品种的叶绿素荧光参数。结果表明,17个建兰品种的光合色素和叶绿素荧光参数具有不同程度的差异,其中‘铁骨素’(C. ensifolium ‘Tiegusu’)、‘逸红双娇’(C. ensifolium ‘Yihongshuangjiao’)和‘闽南黄蝶’(C. ensifolium ‘Minnanhuangdie’)的光合色素含量高于其他品种,表明这3个品种具有良好的光合效率,吸收光能的能力较强;‘铁骨素’最大荧光产量(Fm)、Kautsky诱导效应最大荧光(Fp)、PS Ⅱ原初光能转化效率(Fv/Fm)和非光化荧光淬灭系数(NPQ)均为最高。综上可知,‘铁骨素’的光合生理特性优于其他品种,可作为优良建兰品种进行种植推广。     

低温胁迫下不同甘蔗品种(系)光合特性的变化及其与耐寒性的关系

以广西农科院甘蔗研究所自育的7个新材料和2个生产上的主栽品种为研究对象,在甘蔗苗期进行低温胁迫处理,研究了各品种(系)甘蔗形态特征的冷害指数、叶绿素含量及光合特性相关指标的变化及其光合特性相关指标与甘蔗抗寒性间的相关性。结果表明:随着低温胁迫处理时间的延长,冷害指数不断增大,但变化的大小与快慢因品种(系)不同表现不一样。各甘蔗品种(系)叶片叶绿素含量均随时间延长而降低。叶片净光合速率、气孔导度在低温处理与常温处理间具有显著差异。低温胁迫处理显著降低了各甘蔗品种(系)最大光化学效率(Fv/Fm)、PSⅡ实际光能转化效率ΦPSⅡ、光适应下PSⅡ反应中心的最大光能转化效率Fv′/Fm′、光化学猝灭系数qP、电子传递速率ETR,而显著提高了初始荧光Fo、稳态荧光Fs、非光化学猝灭系数qNP。相关性分析表明整个测定时期各指标间相关显著,Fv/Fm、Fv′/Fm′、ΦPSⅡ与冷害指数I之间的相关系数在0.800以上,Fv/Fm、Fv′/Fm′、ΦPSⅡ可以作为甘蔗品种(系)抗寒性鉴定的重要参考指标。     

基于SSR分子标记的茶树新品种‘戚家美铭’的亲缘关系分析

目的：探明茶树新品种‘戚家美铭’的亲缘关系。方法：以‘戚家美铭’和同其栽种于同一茶园的两个茶树品种‘鸠坑’和‘乌牛早’，以及叶片形状类似的近似品种‘嘉茗一号’作为研究对象，利用21对SSR引物对其进行聚类分析。结果：21对引物共扩增出102个条带，每个SSR位点的观测等位基因数为2～7个，平均值为4.857 1，多态性达到100%,Shannon多态性信息指数范围在1.906 2～0.693 1，平均值为1.449 5，‘戚家美铭’与‘鸠坑’的遗传距离为1.343 7、遗传相似系数为0.260 9。结论：确定‘戚家美铭’是‘鸠坑’的自然杂交后代。     

温州蜜柑叶片气体交换和叶绿素荧光对低温的响应

研究了低温对温州蜜柑叶片气体交换和叶绿素荧光的影响 ,结果表明 :(1) 8℃低温处理 18h对气体交换和叶绿素荧光影响不大。 (2 ) 2℃低温处理 15h后 ,净光合速率 (Pn)、气孔导度 (Gs)、羧化效率 (CE)下降 ,胞间CO2 浓度 (Ci)升高 ,表观量子效率 (AQY)和叶绿素荧光参数F0 及Fv/Fm没有显著变化。 (3)室外自然低温处理 2和 7d ,Pn、Gs、CE、饱和CO2 光合速率、AQY及Fv/Fm显著下降 ,Ci及F0 显著升高 ;在 2 0℃室内 ,Fv/Fm、F0 和AQY比CE和Pn恢复快。 (4 )低温胁迫使Jf(依据叶绿素荧光参数计算所得的电子传递速率 )和Jc(依据CO2 同化测定所得的电子传递速率 )下降 ,Jf/Jc 值升高。 (5 )低温处理降低了Pn和光呼吸速率 (Pr) ,但Pr下降的速率小于Pn下降的速率     

自然越冬过程中3个茶树品种的生理特性变化及抗寒性评价

以茶树也Camelliasinensis（Linn.）Kuntze页品种‘舒茶早’（‘Shuchazao’）、‘乌牛早’（‘Wuniuzao’）和‘平阳特早’（‘Pingyangtezao’）为实验材料,分析了自然越冬过程中（2011年10月至2012年3月）茶树叶片主要渗透调节物质（可溶性糖、可溶性蛋白质、热稳定蛋白质和脯氨酸）含量、抗氧化酶（SOD、CAT和POD）活性、PSⅡ原初光能转化效率（Fv/Fm）和总叶绿素含量的变化,并应用主成分分析结合隶属函数法对3个茶树品种抗寒性进行综合评价。结果表明：自然越冬期3个茶树品种叶片生理指标随时间推移呈规律性变化,越冬期（12月和1月）与越冬前期（10月）、越冬后期（2月和3月）各指标总体上差异显著,且品种间各指标也有一定差异。可溶性糖、可溶性蛋白质、热稳定蛋白质和脯氨酸含量以及SOD活性均呈先升后降的变化趋势,且峰值多出现在12月或2月;CAT和POD活性、Fv/Fm值和总叶绿素含量则呈先降后升的变化趋势,且均在1月降至最低。主成分分析结果显示：第1主成分（X1）包括可溶性糖含量、SOD活性、CAT活性、POD活性、Fv/Fm和总叶绿素含量,贡献率达到57.97%;第2主成分（X2）包括可溶性蛋白质含量、热稳定蛋白质含量和脯氨酸含量,贡献率达到26.89%。综合评价结果显示：自然越冬期3个茶树品种抗寒性的综合评价值均随时间推移呈先升后降的变化趋势,且均在12月达到最高,据此判断3个茶树品种中‘舒茶早’的抗寒性最强、‘乌牛早’的抗寒性最弱,‘平阳特早’的抗寒性介于二者之间。研究结果显示：在自然越冬过程中供试3个茶树品种的抗寒性与其生理指标变化及生长表现一致,表明综合评价法可用于茶树抗寒性评价。     

不同供镁水平对两菊芋品种幼苗生物量、光合和叶绿素荧光特性的影响

采用砂培方式研究了不同供镁水平对"南芋1号(Nanyu No.1)"和"青芋2号(Qingyu No.2)"幼苗生物量、光合特性和叶绿素荧光特性的影响。结果表明:缺镁使菊芋叶片叶绿素含量显著降低,干物质积累减少,净光合速率、蒸腾速率和光合电子传递速率显著下降、CO2同化受抑制,同时Fv/Fm、ΦPSII、qP和qN也显著下降,加重了叶片受到光抑制的程度;随着供镁水平的增加,菊芋的干物质积累,叶绿素含量,光合参数和各系列荧光参数均呈现先增加后降低的趋势;南芋1号和青芋2号在镁离子浓度分别为3和6mmol.L-1,叶片的净光合速率、Fo、Fm、Fo’、Fm’、Fv/Fm、ΦPSII、ETR达到最高值,叶绿素a、b及总叶绿素含量也最多,干物质积累量最大;南芋1号的各系列荧光参数、光合参数、叶绿素含量和干物质积累量均显著高于青芋2号。     

低温胁迫对不同基因型小麦品种光合性能的影响

选用不同基因型小麦品种(春性品种扬麦18、弱春性品种郑麦9023、半冬性品种烟农19),研究了分蘖期和拔节期低温对叶片光合和叶绿素荧光特性的影响.结果表明:分蘖期-10℃低温处理后,烟农19的净光合速率(Pn)、气孔导度(gs)、PSⅡ最大光化学效率(Fv/Fm)、光化学猝灭系数(qP)、非光化学猝灭系数(NPQ)和PSⅡ非循环光合电子传递速率(ETR)显著高于扬麦18和郑麦9023;郑麦9023的gs、Fv/Fm、qp和NPQ显著高于扬麦18,胞间CO2浓度(Ci)显著高于烟农19;扬麦18的Ci显著高于烟农19,初始荧光(Fo)显著高于郑麦9023和烟农19.拔节期0℃低温处理后,烟农19的Pn、gs、Fv/Fm和qP显著高于扬麦18和郑麦9023,NPQ和ETR显著高于扬麦18;郑麦9023的Pn、gs、Fv/Fm和qP显著高于扬麦18,Fo显著高于烟农19;扬麦18的Ci和Fo显著高于郑麦9023和烟农19.分蘖期和拔节期低温胁迫下,半冬性品种烟农19具有较高的光合活性和较强的自我保护机制,弱春性品种郑麦9023次之,春性品种扬麦18最低.     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

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.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

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.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

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.     

A molecular phylogeny of Hebeloma species from Europe

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.     

Taxonomic status of the species of the green algal genusNeochloris

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.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

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.

     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

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.     

Systematic significance of mature embryo of bamboos

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.