Survey of faba bean (Vicia faba L.) for viruses in Morocco

A total of 52 faba-bean (Vicia faba L.) fields, located in the main growing areas in Morocco were surveyed for viruses. From 240 samples with symptoms suggestive of virus infection, the following viruses were detected using electron microscopy, serology, and biological indexing: Alfalfa mosaic virus (AMV), bean yellow mosaic virus (BYMV), broad bean mottle virus (BBMV), broad bean stain virus (BBSV), broad bean true mosaic virus (BBTMV), pea earlybrowning virus (PEBV), pea enation mosaic virus (PEMV), pea seed-borne mosaic virus (PSbMV), and a complex of luteoviruses including bean leafroll virus (BLRV). This is the first report of the occurrence of BBTMV, PEMV, PSbMV, and the luteoviruses (including BLRV) of faba bean in Morcco. The luteoviruses and BBMV were found to be the most prevalent. They were detected in 56 and 50%, respectively, of the surveyed fields; while AMV, BBSV, and PEBV were found in single fields only. The remaining viruses were less prevalent, and were detected in a range of 4 to 15% of the fields surveyed. The incidences per field of the prevalent viruses varied and ranged from 1 to 33% for BBMV and up to 20% in the case of luteoviruses. BBMV was found confined to the central and northern parts of the country, BBTMV and PEMV mainly occurred in the central area, while the luteoviruses and BYMV were spread over the faba-bean growing regions of the country.     

Virus infection and reproductive losses in faba bean (Vicia faba L.)

The viruses, bean yellow mosaic ( BYMV ), Echtes Ackerbohnenmosaik (EAMV) and bean (pea) leaf roll ( BLRV ) reduced seed yield in faba bean particularly when plants were infected at the pre-and mid-bloom stage. EAMV and BYMV , but not BLRV , delayed senescence and increased branching on glasshouse-grown plants so that more inflorescences were produced on diseased plants; most of the additional flower buds necrosed. All three viruses increased the proportion of flower buds that became necrotic thus reducing the number of mature flowers available for pollination. This, together with enhanced abscission of recently set flowers, diminished pod production. Flower set per se was unaffected by infection. The number of ovule sites per pod and weight of individual mature seeds were also unaffected by these diseases but productivity per pod declined because of increased ovule abortions. Patterns of pod production on the inflorescence and location of mature seeds within the pod were unaffected by virus infection.     

Broomrape control in faba bean (Vicia faba L.) with glyphosate and imazaquin

Field studies were carried out to evaluate the efficacy of imazaquin and glyphosate in controlling broomrape (Orobanche crenata Forsk. and O. aegyptiaca Pers.) in faba bean (Vicia faba L.) in Northern Syria. Several rates and times of application of the herbicides were tested. Nearly complete control of broomrape was achieved with both the herbicides when they were sprayed twice (when the broomrape attachments to the faba bean roots were at tubercle stage of develoment and 15 days later) at a rate of application of 80 g a.i. ha^?1 for glyphosate and 10 g a.i. ha^?1 for imazaquin. However, the yield of faba bean did not increase with these treatments, suggesting that the herbicides at these rates were still causing some physiological disorder in the plant that counteracted the beneficial effect of broomrape control on the performance of faba bean plants.     

Broad bean mottle virus: Identification,host range,serology, and occurrence on faba bean (Vicia faba) in West Asia and North Africa

One of the faba bean viruses found in West Asia and North Africa was identified as broad bean mottle virus (BBMV) by host reactions, particle morphology and size, serology, and granular, often vesiculated cytoplasmic inclusions. Detailed research on four isolates, one each from Morocco, Tunisia, Sudan and Syria, provided new information on the virus.The isolates, though indistinguishable in ELISA or gel-diffusion tests, differed slightly in host range and symptoms. Twenty-one species (12 legumes and 9 non-legumes) out of 27 tested were systemically infected, and 14 of these by all four isolates. Infection in several species was symptomless, but major legumes such as chickpea, lentil and especially pea, suffered severely from infection. All 23 genotypes of faba bean, 2 of chickpea, 4 of lentil, 11 out of 21 ofPhaseolus bean, and 16 out of 17 of pea were systemically sensitive to the virus. Twelve plant species were found to be new potential hosts and cucumber a new local-lesion test plant of the virus.BBMV particles occurred in faba bean plants in very high concentrations and seed transmission in this species (1.37%) was confirmed.An isolate from Syria was purified and two antisera were produced, one of which was used in ELISA to detect BBMV in faba bean field samples. Two hundred and three out of the 789 samples with symptoms suggestive of virus infection collected in 1985, 1986 and 1987, were found infected with BBMV: 4 out of 70 (4/70) tested samples from Egypt, 0/44 from Lebanon, 1/15 from Morocco, 46/254 from Sudan, 72/269 from Syria and 80/137 from Tunisia. This is the first report on its occurrence in Egypt, Syria and Tunisia. The virus is a potential threat to crop improvement in the region.Samenvatting Eén van de in West-Azië en Noord-Afrika in faba-boon aangetroffen virussen werd geïdentificeerd als het tuinbonevlekkenvirus (broad bean mottle virus) op grond van waardplantreacties, deeltjesvorm en-grootte, serologische eigenschappen en granulaire, vaak gevacuoliseerde celinsluitsels. Verder onderzoek aan vier isolaten uit respectievelijk Marokko, Tunesië, Soedan en Syrië verschafte nieuwe informatie, over het virus.De in ELISA of gel-diffusietoetsen serologisch niet te onderscheiden isolaten verschilden enigszins in waardplantenreeks en symptomen. Van 27 getoetste plantesoorten werden 21 systemisch geïnfecteerd (12 vlinderbloemigen, en 9 niet-vlinderbloemigen) waarvan 14 door alle vier isolaten. In vele ervan was de infectie symptoomloos, maar belangrijke als gewas geteelde vlinderbloemigen, zoals erwt, linzen en kekererwt, leden ernstig onder aantasting. Alle 23 getoetste faba-boongenotypen, beide van kekererwt, alle vier van linzen, 11 van de 21 getoetste vanPhaseolus-boon en 16 van de 17 van erwt bleken systemisch gevoelig voor het virus. Twaalf plantesoorten, bleken nieuwe potentiële waardplanten en komkommer een nieuwe lokale-lesietoetsplant voor het virus te zijn.In faba-boneplanten kwam, het virus in hoge concentratie voor en overdracht met zaad (1.37%) in deze soort kon worden bevestigd.Een Syrisch isolaat werd gezuiverd en twee antisera werden bereid, waarvan één werd gebruikt voor de detectie van het virus in te velde verzamelde monsters. Van 789 in 1985 tot en met 1987 verzamelde bladmonsters, met symptomen die deden denken aan virusinfectie, bleken 203 het virus te bevatten en wel 4 van de 70 (4/70) uit Egypte, 0/44 uit Libanon, 1/15 uit Marokko, 46/254 uit Soedan, 72/269 uit Syrië en 80/137 uit Tunesië. Het virus was nog niet eerder aangetoond in Egypte, Syrië en Tunesië.De grote verbreiding, grote kunstmatige waardplantenreeks, overdracht met zaad, en pathogeniteit voor een aantal belangrijke vlinderbloemige gewassen maken het virus tot een potentiële bedreiging van de programma's tot verbetering van de teelt van de bedoelde gewassen in het betrokken gebied.     

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.     

Physoderma,not Olpidium,is the true cause of faba bean gall disease of Vicia faba in Ethiopia

Faba bean gall (FBG) is a devastating disease of faba bean (Vicia faba) in Ethiopia. Studies were undertaken first to compare and contrast similarities between FBG disease symptoms and morphology in Ethiopia with those reported earlier in China and, secondly, to identify definitively the FBG causal agent, previously considered as Olpidium viciae, through molecular studies. Morphological studies confirmed an epibiotic phase of zoosporangia for dispersing zoospores, characteristic of Physoderma but not Olpidium, and did not show critical diagnostic characteristics of Olpidium such as presence of numerous short zoosporangial discharging tubes, or binucleate resting sporangia. Recognizing this epibiotic phase is a foundation for comprehending FBG epidemiology and will allow forecasting of zoospore release to highlight best timings for applications of chemical sprays to reduce reinfection cycles. Sequences of partial ITS1-5.8S-partial ITS2, the 18S-ITS1-5.8S-ITS2-part of 28S rRNA, and LSU (28S rRNA) derived from tissue with symptoms confirmed Physoderma, and not Olpidium, as the causal agent. Sample sequences were either close to Physoderma or the contaminant ascochyta pathogen Didymella. From symptom, morphological, and molecular data, the causal agent of FBG disease in Ethiopia is Physoderma. From observations of symptoms that Physoderma can cause, it was determined that this Physoderma crosses over between different legume host genera (e.g., Vicia, Pisum, Trifolium), highlighting the significant biosecurity risk for countries currently free of FBG.     

Seed bank and other demographic parameters of broomrape (Orobanche crenata Forsk.) populations in faba bean (Vicia faba L.)

A study on the population dynamics of broom-rape (Orobanche crenata Forskal) in faba bean (Viciafaba L.) was conducted in two locations for 8 years. The O. crenata seed bank increased every year in the 20-cm depth arable layer until it reached approximately 4 million (M) seeds m^?2. Seed viability ranged between 53% and 68%, approximately half of the seeds remaining dormant. About 3 × 10^?3% of the seed bank became attached to the root system of the faba beans. Only 9% of the attached broomrapes developed and emerged from the soil, possibly reflecting high levels of intraspecific competition. Maximum broomrape seed production for a population of 53 emerged broomrapes per m² was approximately 4 M seeds m^?2. About 43% of the seeds produced were not incorporated into the soil, most probably as a result of their degradation, decomposition or dispersion. Stock semencier et autres paramètres démographiques de I'orobanche crénelée (Orobanche crenata Forsk.) dans des cultures de féverolle (Vicia faba L.) Une étude de la dynamique de populations d'orobanche crénelée (Orobanche crenata Forsk.) dans des cultures de féverolle (Viciafaba L.) a été menée pendant 8 années sur deux sites. Le stock semencier de O. crenata a augmenteéchaque année dans la couche (20 cm) arable du sol jusqu'à atteindre 4 millions (M) de graines m^?2. La viabilité des graines était comprise entre 53 et 68%, approximativement la moitié d'entre elles présentaient une dormance. Environ 3 × 10^?3% du stock semencier adhérait au système racinaire de la féverolle. Seulement 9% des orobanches adhérantes se développaient et levaient, ce qui pourrait refléter une compétition intraspécifique importante. La production maxi-male de graines par une population de 53 orobanches levées au m²était d'environ 4 M graines m^?2. Environ 43% des graines produites n'étaient pas incorporées au sol, très prob-ablement en raison de leur dégradation, de leur décomposition ou de leur dispersion. Bodensamenbank und andere populationsde-mographische Parameter der Sommerwurz Orobanche crenata Forsk. in Bestanden der Acker-Bohne (Vicia faba L.) Bei einer Untersuchung der Populationsdy-namik der Sommerwurz Orobanche crenata Forsk. in Beständen der Acker-Bohne (Vicia faba L.) an 2 Orten über 8 Jahre hin nahm die Bodensamenbank in der Pflugzone von 20 cm Tiefe jedes Jahr zu, bis sie rund 4 Millionen Samen m^?2 erreichte. Die Lebensfähigkeit der Samen lag bei 53 bis 68%, etwa die Hälfte war dormant. Ungefähr 3 × 10^?3% kamen mit den Bohnenwurzeln in Berührung. Nur 9% davon entwickelten sich und wuchsen heran, worin vielleicht der hohe Grad intraspezifischer Konkurrenz zum Ausdruck kommt. Die höchste Zahl gebildeter Samen eines Sommer-wurzbestands von 53 Pflanzen m^?2 war rund 4 Millionen. Etwa 43% der gebildeten Samen gelangten nicht in den Boden, wahrscheinlich weil sie zerstört oder verweht wurden.     

Genotypic influences on the incidence of infection by Ascochyta fabae in winter-hardy faba beans (Vicia faba)

Variation in resistance to Ascochyta fabae among winter-hardy genotypes of faba bean was demonstrated in artificially inoculated field trials. The incidence of seed infection after harvest was strongly correlated with both foliar and pod infection. Joint regression of the incidence of pod infection on flowering date and length of straw accounted for 33–56% of the variance but this largely reflected the behaviour of the entries with a determinate habit which were very susceptible and sensitive to infection by A. fabae. Two indeterminate lines which were similar to each other in flowering date and straw length contrasted greatly in the incidence of foliar and pod infection.     

A mild strain of broad bean mottle virus from faba bean (Vicia faba L.) in the Sudan

A new strain of broad bean mottle virus, isolated from faba bean (Vicia faba L.) in the Sudan, is described. It differs considerably from known isolates by its nearly symptomless infection of faba bean in spite of high concentrations of the virus in infected plants. It does not differ from regular isolates in gel-diffusion serology, light and electron microscopy, host range and symptoms in major hosts other than faba bean. It may constitute a potential threat to other food legumes in the region.     

Pea seed-borne mosaic virus: occurrence in faba bean (Vicia faba) and lentil (Lens culinaris) in West Asia and North Africa,and further information on host range,transmission characteristics,and purification

In a survey for viruses of cultivated legumes in West Asia and North Africa, pea seed-borne mosaic virus (PSbMV) was found in faba bean, lentil and pea. Using ELISA, it was detected in 107 out of 1554 faba bean samples and 40 out of 496 lentil samples with virus-like symptoms collected in Algeria, Egypt, Ethiopia, Jordan, Lebanon., Libya, Morocco, Sudan, Tunisia and Turkey.A pea isolate (SP9-88) from Syria was further characterized. Out of 57 plant species tested, 35 were found susceptible, 19 of which are newly reported hosts of the virus. The virus was transmitted efficiently in the non-persistent manner by five aphid species, especiallyMyzus persicae. Purification from systemically infected faba bean plants yielded 10–15 mg of purified virus per kg of infected tissue. Sap-inoculation of the food and forage legume species chickpea, faba bean, lentil, pea,Vicia narbonensis, V. sativa, Lathyrus ochrus andL. sativus at flowering stage led to 66.0, 40.5, 44.6, 49.2, 31.7, 7.5, 35.7 and 12.0% yield loss, respectively, and to seed-transmission, rates of 0.7, 6.0, 10.8, 1.1, 0.3, 0.2 and 0.4%, respectively. No transmission was detected in chickpea seed embryo axes. However, the virus was detected in the seed coat of SPbMV-infected chickpea at an estimated rate of 1.81%.     

Phenotypic influences on the incidence of infection by Ascochyta fabae in spring varieties of faba beans (Vicia faba)

Spring beans with a range of different growth habits were assessed for resistance to Ascochyta fabae. Variation in the incidence of both foliar and pod infection was recorded but there was no association between the two. The larger-podded broad bean types had a higher incidence of pod infection relative to foliar infection than the smaller-podded field beans. The effect of straw length on the incidence of A. fabae was investigated using exogenously applied gibberellin to sensitive and insensitive cultivars. This confirmed the association between long straw and low incidence of pod disease.     

蚕豆抗锈病鉴定方法的改进及资源筛选

 蚕豆锈病是由蚕豆单胞锈菌 [Uromyces viciae-fabae (Pers.) Schroet ] 引起的蚕豆最重要的病害之一。为提高蚕豆锈病抗性种质筛选的效率及准确性,本文采用混合菌株在温室条件下苗期接种、成株期评价的方法进行抗性鉴定。以抗病材料K0772和感病材料K90315为对照,对1416份材料(3个年度鉴定材料数量分别为290、517和609份)进行鉴定试验,其中重复鉴定材料77份。抗病对照K0772历年均表现为抗病(R);感病对照K90315分别表现为感病(S)、感病(S)和高感(HS)。不同年份间的病情指数T检验结果显示,对照品种K0772和K90315及重复鉴定材料的3年重复鉴定结果间差异并不显著,具有较好的稳定性。同时,重复鉴定材料组间分别呈极显著、显著、极显著正相关。研究结果表明年度间的重复鉴定结果高度一致,具有较好的稳定性和重复性。通过3年重复鉴定,获得高抗(HR)材料12份,抗病(R)材料47份,中抗(MR)材料18份。因此,利用混合菌源进行苗期接种和在成株期对蚕豆品种锈病抗性进行评价的方法具有较好的稳定性和准确性,该方法可以用于蚕豆锈病综合抗性材料的筛选和抗病育种研究。     

蚕豆抗锈病鉴定方法的改进及资源筛选

 蚕豆锈病是由蚕豆单胞锈菌 [Uromyces viciae-fabae (Pers.) Schroet ] 引起的蚕豆最重要的病害之一。为提高蚕豆锈病抗性种质筛选的效率及准确性,本文采用混合菌株在温室条件下苗期接种、成株期评价的方法进行抗性鉴定。以抗病材料K0772和感病材料K90315为对照,对1416份材料(3个年度鉴定材料数量分别为290、517和609份)进行鉴定试验,其中重复鉴定材料77份。抗病对照K0772历年均表现为抗病(R);感病对照K90315分别表现为感病(S)、感病(S)和高感(HS)。不同年份间的病情指数T检验结果显示,对照品种K0772和K90315及重复鉴定材料的3年重复鉴定结果间差异并不显著,具有较好的稳定性。同时,重复鉴定材料组间分别呈极显著、显著、极显著正相关。研究结果表明年度间的重复鉴定结果高度一致,具有较好的稳定性和重复性。通过3年重复鉴定,获得高抗(HR)材料12份,抗病(R)材料47份,中抗(MR)材料18份。因此,利用混合菌源进行苗期接种和在成株期对蚕豆品种锈病抗性进行评价的方法具有较好的稳定性和准确性,该方法可以用于蚕豆锈病综合抗性材料的筛选和抗病育种研究。     

Induction of systemic resistance in faba bean (Vicia faba L.) to bean yellow mosaic potyvirus (BYMV) via seed bacterization with plant growth promoting rhizobacteria

Journal of Plant Diseases and Protection - In a greenhouse experiment, two plant growth promoting rhizobacteria „Pgpr“ strains (Pseudomonas fluorescens FB11 and a Rhizobium...     

蚕豆马铃薯间作种植对蚕豆赤斑病的防控效果

为系统探索蚕豆赤斑病防控策略,保护农田生态环境,2010-2011连续2年在重庆市3个区县进行蚕豆与马铃薯间作试验。结果表明,蚕豆与马铃薯多样性种植能有效控制蚕豆赤斑病的发生,改善蚕豆产量构成因素,从而提高产量和经济效益。蚕豆与马铃薯间作行比为2∶2时对蚕豆赤斑病的防控效果最好,发病率与病情指数分别为46.5%和26.3,在此模式下经济效益最大,纯收入达18 454.9元/hm2。