基于SPI的近51a晋北地区旱涝变化及干旱事件时空特征研究

利用晋北地区1965-2015年逐月降水数据,计算不同尺度标准化降水指数(SPI),并结合游程理论,分析了晋北地区旱涝变化及不同时间尺度干旱事件时空演变特征。结果表明:晋北地区呈湿润化演变趋势,年SPI以0.0507/10a的速率递增,春、秋、冬季变湿,对年湿润化过程的贡献明显。就干旱事件而言,干旱持续时间、干旱程度和干旱强度均呈递减趋势,晋北地区干旱事件缺水状况有所缓解;1965年气象和农业干旱最严重,1999-2000年水文干旱最严重;河曲是农业和水文干旱的高发区,干旱化趋势也最为明显,五寨呈明显的湿润化趋势,其气象干旱最严重。     

南小河沟流域干旱特征

黄土高原地区生态环境脆弱,干旱的发生严重影响该地区农业生产和经济发展。选用1970—2012年南小河沟流域的降雨资料,使用标准化降雨指数(SPI)对干旱进行描述。对该流域内年及季节尺度SPI序列进行Mann-Kendall检验,并对所建立的不同时间尺度的季节性交乘趋势模型进行验证。结果表明:流域内出现干旱的频率为48.84%,年际SPI变化剧烈,整体向干旱化方向发展。春季干旱有明显的分阶段特征;夏季干旱变化趋势不显著;除1975年以外,秋季干旱变化趋势也不显著;冬季的干旱程度变化比较稳定,主要集中在无旱和轻旱等级之间。季节性交乘趋势模型在年干旱以及秋、冬季干旱评估中效果良好,干旱等级预测合格率均达到71.43%,模型在对干旱等级的分析出现错估时,有向中旱水平辐射的强烈趋势。     

近80年宝鸡市旱涝变化特征分析

文中使用1934-2010年5-9月降水总量资料,分析研究宝鸡近80a旱涝演变规律。结果表明:宝鸡市近80a有向干旱发展的趋势,并且以0.12次/10a的速度增加;旱涝出现的频率为39%和28.6%;旱涝演变具有24a左右的长周期和2a的短周期;20世纪40年代、80年代以偏涝为主;70年代、90年代和21世纪头10年以偏旱为主。宝鸡市近80a以来,年Z指数明显下降,其下降速度为0.16/10a。1953-1990年涝年多、旱年较少,1993年以后旱年多、涝年很少,近年来有旱涝交替的特点。四季的Z指数变化趋势不同,冬、夏季Z指数变化不大,冬季呈略上升趋势;夏季呈微弱的下降趋势;春、秋季呈明显的下降趋势,表明干旱趋势增强,春季最明显,秋季次之。春季涝、旱和正常年基本各占1/3;夏涝、秋涝、冬旱的发生频率高。各季旱涝变化都具有2a的周期。研究结果对旱涝趋势预测和防灾减灾具有一定的参考价值。     

海河流域气象干旱时空特征分析

海河流域干旱频发,素有"十年九旱"的说法。文中基于海河流域537个格点1961-2010年的逐日降水数据,采用标准化降水指数作为气象干旱指标,计算干旱频率、变化趋势率和干旱影响站次比。结果表明:50a来海河流域干旱呈加剧的趋势,其中春旱和冬旱减轻,而夏旱和秋旱加重;干旱影响范围呈波动扩大趋势;干旱发生频率较高的地区主要分布在中部、南部以及西部。     

近37年甘肃省夏季旱涝特征分析

选取甘肃省61个气象站1965～2001年共37 a夏季(6～8月)逐日降水资料,应用正态化Z指数变换,对甘肃省夏季降水进行了旱涝等级划分,并应用EOF、REOF、Maxican hat小波分析等方法对旱涝发生的空间分布和时间演变规律进行了研究.结果表明,就整个夏季而言,干旱出现机率明显高于雨涝;6～7月旱涝机率均等, 7～8月较重干旱的出现机率明显高于较重雨涝.甘肃省夏季旱涝主要存在3种变化模态,并可将旱涝分为5个敏感区.甘肃省旱涝从26a以上尺度范围看呈干旱化趋势,旱涝准4a周期在各个年代均比较显著.     

太阳活动与ENSO事件对汉江谷地旱涝灾害影响分析

为探究汉江谷地旱涝灾害发生机理,根据18个代表站点1960-2010年气象资料,运用Z指数法界定出旱涝灾害等级和年份后,分析太阳黑子活动和ENSO事件对汉江谷地旱涝灾害的关系。结果表明:1)研究时段内汉江谷地呈暖干化趋势,气温以0.136℃/10a的速度上升,降水以15.7mm/10a的速度减少,旱涝灾害的发生呈增加趋势。2)20世纪70-80年代旱涝灾害指数与太阳黑子数呈负相关,80年代后二者呈正相关,太阳黑子的减少趋势与研究区域干旱化趋势相同。3)厄尔尼诺强度增大时研究区域的涝灾增多,拉尼娜发生强度增大时旱灾增多。     

潮白河流域气象水文干旱特征及其响应关系

利用潮白河流域7个气象站1960-2011年逐月降水以及密云水库同时期入库流量数据,分别以SPI和SDI两个干旱指标表征气象、水文干旱,采用游程理论、M-K检验、滑动t-检验、Spearman秩相关检验等方法研究了该流域气象水文干旱特征,并探求水文、气象干旱的响应关系。结果表明：研究期内潮白河流域气象干旱多以短历时干旱事件为主,历时1-2个月的干旱事件达研究期内气象干旱事件总次数的67.18%;但是气象干旱的年干旱烈度及其历时未通过MK趋势显著性检验,其线性斜率值仅为-0.025和-0.005,变化趋势不明显。而水文干旱存在极长历时重烈度干旱事件,历时达4个月以上的干旱事件达研究期内水文干旱事件总次数的46.54%,最长干旱历时达45个月;且研究期内水文干旱的年干旱烈度及其历时均通过显著性检验,线性斜率值达-0.419和0.228,变化显著;二者均在1980年和1998年出现突变现象。自20世纪90年代末以来,潮白河流域水文干旱频繁发生,且多为长历时连续干旱。研究期内水文干旱滞后气象干旱约1个月。     

珠江流域旱涝变化及其与大气环流关系研究

基于珠江流域57个气象站1960-2014年逐日降水量资料,选用标准降水指数(SPI)为旱涝指标,讨论旱涝时空变化特征,研究与极端旱涝相关的大气环流成因。结果表明:(1)珠江流域旱涝严重程度主要受降水量影响,SPI能有效反映流域的旱涝特征;(2)自1980s起,流域有干旱趋势,西北部干旱化趋势显著;(3)流域春旱减缓,秋旱加重,夏季洪涝频发;(4)极端的旱涝变化与大气环流关系密切,西太平洋副热带高压与东亚大槽是两个主要影响珠江流域旱涝变化的环流系统。     

近55年来河西地区干旱时空演变特征及其与ENSO事件的关系

根据河西地区14个气象站点1961-2015年的逐月气象观测资料,基于SPEI指数采用Mann-Kendall趋势检验法、反距离加权插值(IDW)等方法分析了近55年来河西地区年代际、四季干旱及空间变化特征,并探讨了ENSO 事件与该区干旱的关系。结果表明：在年代际变化上,自20世纪90年代以来河西地区干旱次数增多、干旱程度加重。季节时间变化上,河西地区春、夏、秋季均呈干旱化趋势,春季干旱化趋势最为突出,夏季次之,冬季略呈变湿趋势。空间变化上,整个河西地区春季均呈干旱化趋势,而且大部分地区的春旱趋势极为显著,其中春旱趋势最显著的地方是金塔;冬季整个研究区趋于湿润化。各季节干旱高频区分别集中在：春季在金塔、民勤地区,夏季在河西西北部,秋季在河西中东部及西部的安西—玉门一线,冬季在101°E以西的河西地区。河西地区秋季SPEI与SSTA指数的相关性最为显著,春季次之,夏季最弱。ENSO事件发生强度与河西地区SPEI影响因子的多项式拟合关系表明,ENSO事件强度对温度的影响高于降水;其中在ENSO暖事件(厄尔尼诺事件)发生年份,气温有明显的上升趋势;在ENSO冷事件(拉尼娜事件)发生年份,少数年份降水有所增加,对气温的影响较弱。     

气候暖干化背景下黄土高原旱涝时空演变特征

选取58个国家气象基准站1960-2010年逐年降水资料,采用Kriging插值、Mann-Kendall检测及Morlet小波分析等方法,对该区降水及旱涝时空特征进行分析。结果表明：黄土高原暖干化趋势明显,气温、降水突变年份分别在1995年、1990年左右。旱涝等级呈上升趋势,尤以半湿润区最为明显。干旱区发生旱、涝频率最高,涝情略微严重,但干旱更易发生,大旱频次高值中心分散分布,洪涝发生频率西部低、中部高。该区旱涝情势存在多尺度的周期变化,25~30 a的振荡最强,推测涝期即将结束,旱期将要开始。研究成果可为黄土高原旱涝灾害防御提供参考。     

Dermestid beetles in ‘evolution Canyon’, lower Nahal Oren, Mt. Carmel, including new records for Israel

Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr _s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr _s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.     

Epidemiology of Toxigenic Fungi and their Associated Mycotoxins for Some Mediterranean Crops

Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.     

A survey of the genera of<Emphasis Type="Italic">Microgaster</Emphasis> latreille and<Emphasis Type="Italic">Hygroplitis</Emphasis> thomson (Hymenoptera: Braconidae: Microgastrinae) from China

The genera ofMicrogaster Latreille 1804 andHygroplitis Thomson 1895 from China are presented systematically in this paper. Thirty-two species ofMicrogaster and three species ofHygroplitis are known in China. Diagnosis, character variation, distribution and host of each species among the two genera are presented, including its host and distribution. Keys to the species ofMicrogaster andHygroplitis are given. http://www.phytoparasitica.org posting Dec. 19, 2006.     

Plant Viruses Transmitted by Whiteflies

One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.     

Broad bean mottle virus in Morocco; curculionid vectors,and natural occurrence in food legumes other than faba bean (Vicia faba)

Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.     

Characterization of potato potyvirus Y (PVY) isolates from seed potato batches. Situation of the NTN, Wilga and Z isolates

A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVY^N strain and six to the PVY^O strain. No PVY^C was found. Two other isolates reacted serologically like PVY^O, but were unable to elicit a hypersensitive response from the Ny_tbr gene and probably represent the PVY^Z group. At the molecular level, these two isolates showed a combination of both PVY^O and PVY^N and could be recombinants of these strains. Another isolate reacted serologically like PVY^O, but induced vein necrosis in tobacco, like PVY^N-Wilga. Some PVY^N isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVY^NTN group. The PVY^NTN, PVY^N-Wilga and PVY^Z groups probably represent pathotypes within strains PVY^N and PVY^O, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.     

The autumn leafroller: Phenology,damage and parasitoids in a Dutch apple orchard

The phenology of the autumn leafroller,Syndemis musculana, a local pest of apple, was studied in order to forecast larval emergence. From 1983–1986, peak flight as determined with sexpheromone traps was always between 13–18 May. The duration of embryonic development was determined at various constant temperatures and used to estimate the periods of egg hatch in these four years. Each year, most eggs should have hatched in the second decade of June.Differences in attack rates between apple cultivars seem to be explained largely by the variation in picking time. Larvae are only half grown at the beginning of harvest (cv. James Grieve), and have gone into hibernation when the latest variety (cv. Golden Delicious) is picked. Moreover, the varieties Cox's Orange Pippin and Belle de Boskoop, picked about half time, are liable to receive additional damage by caterpillars brought with the picked fruits into storage.Various hymenopterous parasites were reared from caterpillars. As the only leafroller in the orchard which hibernates as mature larva,S. musculana may promote winter survival of some parasitoids, like the eulophidColpyclypeus florus.Samenvatting De fenologie van de herfstbladroller (Syndemis musculana Hübner), een incidentele plaag op appel, werd nader bepaald met het doel het uitkomen van de eieren te kunnen voorspellen. In 1983–1986 viel de piekvlucht, bepaald met behulp van feromoonvallen, steeds tussen 13 en 18 mei.De ontwikkelingsduur van de eieren bij verschillende constante temperaturen werd gebruikt om de periode van uitkomen te schatten. De meeste eieren zullen ieder jaar in de eerste helft van juni uitkomen.Geconstateerde verschillen in schade tussen appelrassen blijken goeddeels terug te voeren op verschillen in pluktijdstip. De rupsen van de herfstbladroller zijn pas half-was als de eerste appels eind augustus geplukt worden, terwijl tegen het einde van de oogst begin oktober de meeste al in winterslaap zijn. Met name tussentijdse rassen, als Cox's Orange Pippin and Schone van Boskoop, lopen extra schade op doordat grotere rupsen met de geplukte vruchten in de kist terecht komen.Uit de rupsen werden negen, al van andere boomgaardbladrollers bekende, sluipwespen gekweekt, Omdat deze bladrollersoort, als enige in de boomgaard, als volgroeide rups overwintert, lijkt zij bij uitstek geschikt als winterwaard.This study was carried out at the Experimental Orchard De Schuilenburg, Schuilenburg 3, 4041 BK Kesteren, the Netherlands, to which address correspondence should be addressed.     

Diagnostics,genetic diversity and pathogenic variation of ascochyta blight of cool season food and feed legumes

Molecular diagnostic techniques have been developed to differentiate the Ascochyta pathogens that infect cool season food and feed legumes, as well as to improve the sensitivity of detecting latent infection in plant tissues. A seed sampling technique was developed to detect a 1% level of infection by Ascochyta rabiei in commercial chickpea seed. The Ascochyta pathogens were shown to be genetically diverse in countries where the pathogen and host have coexisted for a long time. However, where the pathogen was recently introduced, such as A. rabiei to Australia, the level of diversity remained relatively low, even as the pathogen spread to all chickpea-growing areas. Pathogenic variability of A. rabiei and Ascochyta pinodes pathogens in chickpea and field pea respectively, appears to be quantitative, where measures of disease severity were based on aggressiveness (quantitative level of infection) rather than on true qualitative virulence. In contrast, qualitative differences in pathogenicity in lentil and faba bean genotypes indicated the existence of pathotypes of Ascochyta lentis and Ascochyta fabae. Therefore, reports of pathotype discrimination based on quantitative differences in pathogenicity in a set of specific genotypes is questionable for several of the ascochyta-legume pathosystems such as A. rabiei and A. pinodes. This is not surprising since host resistance to these pathogens has been reported to be mainly quantitative, making it difficult for the pathogen to overcome specific resistance genes and form pathotypes. For robust pathogenicity assessment, there needs to be consistency in selection of differential host genotypes, screening conditions and disease evaluation techniques for each of the Ascochyta sp. in legume-growing countries throughout the world. Nevertheless, knowledge of pathotype diversity and aggressiveness within populations is important in the selection of resistant genotypes.     

Characterization of Sclerotinia minor populations in Texas peanut fields

In the summer of 2004 an epidemic of sclerotinia blight of peanut, a disease caused by Sclerotinia minor, occurred in Texas in fields where the disease was never previously detected. The disease was observed on many plants within one of the fields (>3000 disease foci), although most foci were <1 m. It is hypothesized that these observations were inconsistent with the recent introduction of a monocyclic pathogen, even if disease developed under conducive environmental conditions. The pattern of disease is most suggestive of the presence of foliar (ascospore) infections, although air temperature was above the known limits for apothecia development if the pathogen had arrived in the field in 2004 peanut seed. To further examine this epidemic, 232 isolates were collected, across a variety of spatial scales spanning this field and other Texas peanut fields, and evaluated for aggressiveness, fungicide sensitivity and genotypic diversity. There was wide variation among isolates for the phenotypic characteristics measured, but there was no evidence that a genotypically unique, highly aggressive, and fungicide resistant isolate had been introduced or evolved. The predominant genotype, TX1, which contained 154 isolates, was found in every county and field population.     

Tumours of Begonia and some other ornamentals,induced by Corynebacterium fascians

In 1975 many tumours were observed in plants ofBegonia Schwabenland grown in Aalsmeer. Submersion of the roots ofNicotiana megalosiphon seedlings in a homogenate of tumorous tissue, induced tumours after two weeks. Short periods of submergence yielded results similar to those obtained after longer periods. Tumour homogenates lost their infectivity after ten min at 50°C. Aphids transmitted the infectious agent.Treatment with propylene oxide did not inhibit infectivity completely. Filtration through a 450 nm filter removed the infectious agent.Tobacco tumor virus or a viroid could not be isolated. Cultures ofCorynebacterium fascians, isolated from tumours ofN. megalosiphon were highly infectious and induced tumours in healthyN. megalosiphon andBegonia. Tumorous tissue homogenates ofPelargonium zonale, Dahlia sp.,Gladiolus sp., andLilium sp. also caused tumours inN. megalosiphon, from whichC. fascians was isolated. It was not possible to produce tumours inN. megalosiphon with homogenates from roses with symptoms of bud proliferation.Samenvatting In 1975 werden vele tumoren waargenomen inBegonia Schwabenland op Aalsmeerse bedrijven (Fig. 1). De infectiositeit van tumorweefsel kon goed en snel worden vastgesteld door de wortels van zaailingen vanNicotiana megalosiphon in een homogenaat van tumorweefsel te dompelen. Tumoren ontstonden na twee weken, de eindbeoordeling geschiedde na een maand (Fig. 2). Ook verschillende andereNicotiana spp.,Melilotus officinalis (Fig. 3) enPisum odoratum (Fig. 4) werden aangetast.Bij de infectiositeitstoets gaven zeer korte dompeltijden even goede resultaten als langere (Tabel 1). Infectieus sap verloor zijn infectievermogen na 10 min verhitting bij 50°C. Bladluizen brachten de smetstof over. Propyleenoxide verminderde de infectiositeit wel, doch onderdrukte deze niet totaal. Bij filtratie door een 450 nm filter bleef het infectieuse agens op het filter achter. Het tumor-inducerende agens was ook aanwezig in die delen van planten met tumoren welke gezond leken en het ging voor een gering deel over met zaad (Tabel 2).Uit tumoren konden wij geen tabakstumorvirus of een viroïde isoleren. Culturen vanCorynebacterium fascians, geïsoleerd uit tumoren vanN. megalosiphon bleken zeer infectieus en veroorzaakten tumoren inN. megalosiphon enBegonia. Homogenaten van tumorweefsel vanPelargonium zonale, dahlia (Fig. 5), gladiool (Fig. 6) enLilium Mid Century Hybrid Enchantment (Fig. 7) veroorzaakten ook tumoren opN. megalosiphon, waaruitC. fascians werd geïsoleerd. Met sap van kroeskopzieke rozen konden wijN. megalosiphon niet besmetten.