内蒙古马铃薯干旱等级指标研究

根据马铃薯各生长发育阶段对水分的需求规律,结合内蒙古实际降水供水情况确定了作物水分亏缺指数为表征马铃薯水分亏缺程度的指标.利用内蒙古地区有代表性的26个种植站点1981—2015年的马铃薯产量资料和降水量等气象资料,开展水分亏缺指数和减产率、相对生长高度的相关分析,建立该区域马铃薯干旱灾害等级指标,结合中国气象局行业标...     

河北省冬小麦旱灾风险评估和区划方法研究

分别以冬小麦年雨量平均值±0.5倍样本标准差和平均值±1.5倍样本标准差界定不同等级的干旱年份,以气象产量减产大于等于3%界定冬小麦受灾年份,分析了河北省各市冬小麦旱年的平均减产率及其空间分布,研究了冬小麦不同旱灾强度的频率分布规律.提出了冬小麦干旱灾害风险指数的概念和计算方法,分析了河北省冬小麦干旱灾害风险指数的区域分布规律,并以旱年平均减产率、干旱灾害风险指数和冬小麦年雨量等因子为指标,利用地理信息技术将全省冬小麦种植区区划为干旱灾害高、中、低3种风险区,并探讨了各类风险区不同旱灾年景的平均减产率和防灾减灾措施.     

北方冬小麦不同生育期干旱风险评估

基于北方6省市和61个市县1981—2012年冬小麦产量和逐日气象资料,有效分离冬小麦减产率,通过典型干旱年份冬小麦减产率与水分亏缺距平指数、降水距平百分率的相关分析筛选致灾因子;基于减产率分级,利用冬小麦不同生育期减产率与致灾因子数学模型构建干旱等级指标;综合冬小麦干旱等级的强度及其风险概率,进行冬小麦生育期干旱风险评估。结果表明:冬小麦减产率与水分亏缺距平指数的相关系数达0.355~0.656,明显大于降水距平百分率,在各生育阶段内均通过0.05的显著性检验,确定为干旱致灾因子;在冬小麦不同生育期内,通过冬小麦减产率-致灾因子线性模型得到的轻、中、重、特重干旱等级指标,以0.297、0.351、0.214、0.159、0.316、0.547、0.149分别为苗期、越冬期、返青期、拔节期、抽穗期、成熟期和全生育期发生干旱的临界值;不同生育期冬小麦干旱风险分布形式存在一定地区差异,这与地区降水量对冬小麦需水的满足情况相符,其中,河北南部和山东西北部在各生育期均属于冬小麦干旱的高危险性地区。     

辽宁省主要粮食作物产量灾损风险评估

从产量灾损风险的角度,利用1971～2008年辽宁省主要粮食作物玉米和水稻的产量资料,构建了辽宁省粮食产量灾损风险评估模型,从历年平均减产率、灾年减产率变异系数、产量灾损风险指数等角度综合评估了辽宁省粮食产量的灾损风险.结果表明:辽宁大部都是玉米生产的低风险区,高风险区主要分布在朝阳和锦州地区,大连、鞍山和葫芦岛为中风...     

马铃薯与玉米不同套种模式对马铃薯青枯病的防治作用

田间调查比较马铃薯与玉米不同套种模式对马铃薯青枯病的控制作用结果表明,马铃薯套种玉米可减少青枯病病菌在株行间的蔓延,抑制马铃薯青枯病的发生。套种田块的青枯病发生率、大中薯减产率和单株减产量均低于纯种田块。马铃薯与玉米二套二种植模式对马铃薯青枯病的防治作用最为明显,发病率仅为纯种模式的60%左右。     

基于产量灾损的冬小麦干热风综合风险区划

利用河南省118个县气象站逐日气象资料、作物耕地面积和灌溉面积等资料,30个农业气象观测站产量、产量结构及作物发育期资料,通过分解气象产量和假设千粒重期望值的方法,提取出了灌浆期气象产量,考虑减产风险概率、千粒重变异系数等指标,构建了干热风产量灾损风险指数。将产量灾损风险与灾害气候风险区划结果相结合,制定了干热风灾害综合风险区划。结果表明：提取的灌浆期气象产量呈正态分布,各代表站干热风发生年份的平均减产率为7.4%;干热风产量灾损的低风险区占全区域的43.3%,中度风险区占36.7%,高风险区占20%。襄城、方城、西平和驻马店等地干热风灾害综合风险指数均在0.5以上,是产量灾损高风险与气候高风险的重叠区,低风险区位于伊川、南阳、郑州、太康和淮河以南大部。     

阴山北麓农牧交错带不同沟垄宽度集雨技术对马铃薯的影响

为研究和解决阴山北麓农牧交错带地区降水资源不足、雨养农业产量不稳的问题,于2011~2012年在内蒙古武川县进行了不同垄宽和沟宽的集雨措施栽培马铃薯的试验,测定了沟垄集雨处理下土壤水分状况、马铃薯生长、产量和水分利用效率。结果表明:沟垄集雨技术提高了种植区土壤水分,增幅16.1%~26.0%。马铃薯生育期内的叶面积指数和单株干物重均高于对照处理。沟垄集雨处理的商品薯率较平作高5.0~30.5%,商品薯产量高于平作,垄宽1.0m沟宽1.0m集雨处理商品薯产量平作增产52.0%~81.0%。较平作相比,集雨处理提高了马铃薯水分利用效率。沟垄集雨技术对阴山北麓农牧交错带地区雨养农业规避干旱气候风险以实现马铃薯稳产具有重要的应用价值。     

盘县马铃薯主要病害发生及防治措施

近年来马铃薯种植面积较大但产量较低,制约盘县马铃薯产业发展的主要因素就是马铃薯病害.由于病害发生,造成马铃薯减产在20%～60%,通常表现为产量降低、外观品质较差、营养价值低、生产效益低,制约着马铃薯产业的发展.     

河北省冬小麦春季霜冻害发生规律及风险分析

根据河北省1971-2010年冬小麦春季霜冻害灾情资料、逐日气象资料,建立了以气温稳定通过12℃为临界期的冬小麦霜冻害判别指标;分析了霜冻害时空变化特征;根据灾害风险分析原理,建立了霜冻害风险指数,进行了相应的风险区划,并初步探讨了霜冻害对冬小麦产量的影响。结果表明:河北省霜冻害以轻度为主,90年代以后发生霜冻害的站点数年际间变化幅度较90年代以前明显增大,站点数量明显增多;霜冻害总站点数存在明显的4a、7a和11a周期,90年代中期以后7a周期消失,11a周期逐渐缩短为8a周期;霜冻害高发区分布在邯郸、邢台、保定西北部以及沧州和衡水两市的部分地区,低发区分布在唐山、秦皇岛地区;霜冻害风险以中度和低度为主,中度风险区分布在邯郸西部、邢台大部、沧州南部、保定西北部,其它麦区大部为低风险区。霜冻害影响冬小麦产量的形成,发生强度与冬小麦气象产量呈负相关(r=-0.346)、与减产率呈正相关(r=0.342)。     

基于气象因子驱动的阴山地区马铃薯产量预测模型

为了及时掌握马铃薯产量,提高产中、产后气象服务能力,指导马铃薯生产,以内蒙古阴山旱作区马铃薯生产为例,利用16个旗县1980-2007年气象和产量资料及发育期等其它相关资料,采用相关和回归分析等方法,分区域分析了影响马铃薯产量的关键气象因子,并建立了气象产量预测模型.结果表明:(1)降水是影响产量的关键因子,温度次之;前山地区高温胁迫的影响大于后山,降水不足的影响则相反;干旱少雨、高温胁迫是制约该地区马铃薯产量提高的主要因素.(2)用逐步回归方法建立的幼苗期-结薯期、幼苗期-淀粉积累期、结薯期-淀粉积累期和生长季4个时间段的气象产量预测模型均达到极显著水平,拟合率75％以上,产量预测平均误差11.1％,误差变幅0.34％ ～ 27.9％,近85％的预测值准确率超出80％,对区域预测结果好于各旗县;(3)结薯期是对水热最敏感的时期;不同时间段模型中以生长季和幼苗-结薯期模型预测结果较好.所建模型可以在马铃薯产量预测业务中应用.     

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.     

Eyespot of Cereals Revisited: ITS phylogeny Reveals New Species Relationships

Four species so far classified in Pseudocercosporella or Ramulispora (hyphomycetes) are associated with eyespot disease symptoms of cereals. Two of these have been linked to teleomorphs that were described in Tapesia. Sequence data derived from the Internal Transcribed Spacer region (ITS1, 5.8S and ITS2) of the rDNA operon showed, however, that the eyespot fungi associated with Tapesia are not congeneric with Ramulispora sorghi, the type of Ramulispora. The genus name Tapesia is now rejected in favour of the conserved name Mollisia, which appears to comprise heterogeneous fungi. Tapesia yallundae is not closely related to the type of Mollisia, M. cinerea, but clusters separately, being more closely allied to species with Cadophora anamorphs. A new holomorph genus, Oculimacula, is therefore proposed for teleomorphs of the eyespot fungi, while the anamorphs are accommodated in Helgardia gen. nov.