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1.
甘肃天水地区豆科植物共生固氮资源调查   总被引:8,自引:1,他引:8  
调查了甘肃天水地区33属71种豆科植物的结瘤固氮状况,其中29种为Allen文献中未记载的结瘤豆科植物,新发现结瘤豆科植物20种,该地区根瘤大多圆形、棒状,形态较为规则,对120多个根瘤样品的乙炔还原活力测定表明,36.5%为无效根瘤,不同种豆科根瘤其活性相差不大,一般均较低,乙炔还原活力小于1μmolC2H4/g·h的豆科根瘤占35%,最高者仅37.73μmolC2H4/g·h(米口袋状棘豆)。  相似文献   

2.
玄参科马先蒿的结瘤固氮现象   总被引:1,自引:1,他引:1  
笔者在进行豆科植物根瘤菌资源考察时,在甘肃民乐县发现玄参科马先蒿可以形成根瘤,并具有乙炔还原活性。玄参科植物的结瘤固氮现象未见文献记载(文献查至1990年)。  相似文献   

3.
宁夏豆科植物根瘤菌资源调查及其生态分布   总被引:3,自引:2,他引:1  
通过对宁夏野生及栽培豆科植物结瘤固氮资源的调查,从24属47种豆科植物根部采集到根瘤样品748份,通过调查显示:兴隆山棘豆和单叶黄芪为新发现的豆科结瘤植物;此地区根瘤主要为黄色或褐色,性状以球形和棒状为主,主要着生在侧根;影响宁夏豆科植物结瘤的因素有水分、土壤肥力和植物的生育阶段;根据生长习性、地理分布和利用状况,将宁夏豆科植物根瘤菌资源分为干旱区、山坡草地区和耕地区.  相似文献   

4.
对祁连山部分地区豆科植物根瘤菌资源进行了调查,从9属32种野生豆科植物根部采集到根瘤样品427份。调查结果显示:调查区豆科植物资源种类丰富,所采集根瘤形状多为棒状、掌状及不规则状,颜色以粉色和黄色为主,着生部位主要为侧根;影响该区豆科植物结瘤的因素除与寄主植物生育阶段及遗传特性有关外,还与地形、土壤、气候、生物及人为因子等多种生态因素密切相关,其中地形及土壤是影响结瘤的关键因子。  相似文献   

5.
我国西北部分地区豆科植物根瘤菌资源调查研究   总被引:4,自引:1,他引:3  
通过对青海、甘肃、宁夏和陕西部分地区豆科植物根瘤菌资源调查,共采集到根瘤样品1850份,包括野生和栽培豆科植物有20属41种,采集的根瘤86%着生在侧根或须根上,根瘤的形状主要有棒状、掌状、球状、珊瑚状,颜色多为黄色、粉色,少数呈白色或褐色.调查研究发现,六盘山棘豆为新发现的豆科结瘤植物;兴隆山棘豆为青海新记录植物.豆科植物与根瘤菌共生结瘤及根瘤特征,除了与寄主植物的遗传特性、发育时期有关外,还与其所处的生态环境(水分、温度、光照、土壤结构、土壤pH等)有密切的关系.  相似文献   

6.
甘肃中西部豆科植物根瘤菌多样性调查研究   总被引:4,自引:3,他引:1  
通过对甘肃中西部地区豆科植物共生固氮资源多样性的调查,共获得豆科植物根瘤样品452份,涉及18个属,30个种,分离得到328株根瘤菌。调查结果显示:(1)本地区豆科植物资源贫乏,但适应性强,大多数都具有抗干旱、耐盐耐碱特性。(2)土壤干旱和土壤高盐浓度是影响根瘤形成的重要限制因子。(3)本地区豆科植物根瘤形状多为棒状、球状,部分为不规则状;颜色为红色、浅褐色、褐色、黄色,部分为白色、黑色。(4)许多豆科植物——根瘤菌共生固氮体系已被广泛应用于防风固沙、防治水土流失及改善生态环境等方面。  相似文献   

7.
我们对新疆干旱区20属38种豆科根瘤的吸氢、放氢和固氮作用进行了研究。测定了约200个根瘤样品吸氢活性,除短命豆科黄芪根瘤外,均有不同程度的吸氢活性。大于1 Mmo1H_2·g~(-1)hr~(-1)的有33种。大于5 Mmo1H_2·g~(-1)·hr~(-1)有17种。其中未见报导的具有吸氢活性的豆科根瘤有18种。伴随固氮作用放氢的根瘤有9种。对20种不同属的豆科根瘤进行固氮相对效率的测定,80%的固氮相对效率为1。定点、定期对6种不同属豆科根瘤进行有关项目测定,结果表明吸氢活性与豆科植物生育期有显著关系。现蕾期最高,而后随着植物生长发育逐渐下降,至结荚期为最低。此外,对豆科根瘤吸氢活性与分布地区的相关性等进行了讨论。  相似文献   

8.
甘肃宁夏根瘤菌的分离及回接鉴定   总被引:3,自引:0,他引:3  
从甘肃宁夏干旱地区36属98种豆种植物400余个根瘤样品中分离得到360株根瘤菌,总分离率为87%,以20属22种寄主植物对大部分菌株进行了回接验证,回接结瘤率81.2%,对干埋地区概胶斩采集,根菌的分离及回接技术进行了讨论。  相似文献   

9.
新疆干旱区短命豆科植物弯果胡卢巴结瘤固氮的研究   总被引:3,自引:0,他引:3  
弯果胡卢巴(Trigonella arcuata)是新疆干旱地区的短命豆科植物,生长于早春,生活周期短,约两个月,在盛夏之前就完成了它的一生。它能结瘤固氮,固氮活性变幅较宽。与一般豆科植物不同,苗后期它的根瘤固氮活性最高。根瘤固氮活性受环境条件影响较大,特别是土壤水分条件是植物根瘤固氮活性表达的重要因素。弯果胡卢巴根瘤内存在着吸氢酶体系,在固氮酶作用下,伴随氮的还原而产生的氢气,可以再循环利用,提高了固氮的相对效率。虽然弯果胡卢巴根瘤在各生育期不放氢,固氮效率为1,但是其根瘤内吸氢酶活性与植物生育期有相关性,初花期活性最高。此外,本文对弯果胡卢巴结瘤固氮的生理生态特征及其开发利用的价值进行了讨论。  相似文献   

10.
葡萄根瘤蚜为害症状及其防治陕西农科院植保所韩学俭葡萄根瘤蚜,属同翅目,瘤蚜科,又名葡萄根蚜虫。此虫原产北美东部,已传布世界各国。因其为世界著名的葡萄毁灭性害虫,故被列为国际和国内重要检疫对象之一。此虫只为害Vins属葡萄。1为害症状成、若虫均以刺吸式...  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
Plant Viruses Transmitted by Whiteflies   总被引:18,自引:0,他引:18  
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.  相似文献   

15.
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.  相似文献   

16.
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 PVYN strain and six to the PVYO strain. No PVYC was found. Two other isolates reacted serologically like PVYO, but were unable to elicit a hypersensitive response from the Nytbr gene and probably represent the PVYZ group. At the molecular level, these two isolates showed a combination of both PVYO and PVYN and could be recombinants of these strains. Another isolate reacted serologically like PVYO, but induced vein necrosis in tobacco, like PVYN-Wilga. Some PVYN isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVYNTN group. The PVYNTN, PVYN-Wilga and PVYZ groups probably represent pathotypes within strains PVYN and PVYO, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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