Showing papers on "Heterodera avenae published in 2010"
TL;DR: The incidence, severity and yield loss caused by 40 pathogens associated with 41 diseases of barley were assessed from a survey of 15 barley pathologists covering the winter cereal growing areas of Australia, finding the relative importance of pathogens varied between regions and zones.
Abstract: The incidence, severity and yield loss caused by 40 pathogens associated with 41 diseases of barley were assessed from a survey of 15 barley pathologists covering the winter cereal growing areas of Australia. The survey provided data on the frequency of years that each pathogen developed to its maximum extent, the proportion of the crop then affected in each growing area, and the yield loss that resulted in the affected crops with and without current control measures. These data were combined with crop production and grain quality data to estimate the value of the losses aggregated to the Northern, Southern and Western production regions. Pathogens were estimated to cause a current average loss of $252 × 106/year or 19.6% of the average annual value of the barley crop in the decade 1998-99 to 2007–08. Nationally, the three most important pathogens are Pyrenophora teres f. maculata, Blumeria graminis f. sp. hordei and Heterodera avenae with current average annual losses of $43 × 106, $39 × 106 and $26 × 106, respectively. If current controls were not used, losses would be far higher with potential average annual losses from the three most important pathogens, P. teres f. maculata, H. avenae and P. teres f. teres, being $192 × 106, $153 × 106 and $117 × 106, respectively. The average value of control practices exceeded $50 × 106/year for nine pathogens. Cultural methods (rotation, field preparation) were the only controls used for 14 pathogens and contributed more than 50% of the control for a further 13 pathogens. Breeding and the use of resistant cultivars contributed more than 50% of control for five pathogens and pesticides for four pathogens. The relative importance of pathogens varied between regions and zones.
216 citations
TL;DR: Modelling clearly demonstrated that H. filipjevi is economically important on winter wheat in Iran and showed a significant negative relationship between the initial populations and grain yield.
Abstract: The cereal cyst nematodes, Heterodera avenae , H. filipjevi and H. latipons , are considered to be the most economically important species of cyst-forming nematodes on wheat. Two trials were conducted in 2006 and 2007 to determine the impact of different initial population levels of H. filipjevi (0, 2.5, 5, 10 and 20 eggs and second-stage juveniles (J2) (g soil) −1 ) on wheat cv. Sardari in microplots under natural field conditions in Iran. The results showed that increasing the initial populations of H. filipjevi significantly reduced several growth parameters of wheat (plant height, root dry weight, aerial shoot dry weight and grain yield) compared with the untreated controls. The final population of H. filipjevi increased with increasing initial population, while the reproduction factor ( R f ) declined as the initial population increased but was greater than 1 in all treatments. Regression analysis showed a significant negative relationship between the initial populations and grain yield. The modelling clearly demonstrated that H. filipjevi is economically important on winter wheat in Iran. Grain yield loss was demonstrated even at the lowest population density and reached a maximum loss of 48% with an initial population density of 20 eggs and J2 (g soil) −1 . The aerial shoot yield loss was as great as 40% in both years.
37 citations
TL;DR: Genes encoding cytosolic forms of APX were induced in roots of both lines in response to nematode infection and this induction took place both earlier and with greater intensity in the resistant line than in the susceptible one, and it was also higher in the root area at the site of nematodes attachment.
Abstract: Changes in ascorbate peroxidase (APX) enzyme activity in response to nematode (Heterodera avenae) attack were studied in roots of three hexaploid wheat lines carrying Cre2, Cre5, or Cre7 nematode resistance genes and the susceptible Triticum aestivum cv. Anza. A spectrophotometric analysis was carried out with root extracts of infected plants 4, 7, 11, and 14 days after nematode inoculation using uninfected plant as control. APX induction in infected resistant genotypes was similar and higher than in the susceptible control. The introgression wheat/Aegilops ventricosa H-93-8 line, carrying the Cre2 gene, and its parental line H-10-15 as susceptible control were used to analyze whether this increase of activity was correlated with the induction of APX gene expression. Genes encoding cytosolic forms of APX were induced in roots of both lines in response to nematode infection. This induction took place both earlier and with greater intensity in the resistant line than in the susceptible one, and it was also higher in the root area at the site of nematode attachment.
34 citations
TL;DR: It is proposed that the pathotype code, Ha43, be applied to the population from Xushui, which was consistently characterised over two seasons and differs from the most similar pathotype, Ha13, by being avirulent in oat cv.
Abstract: A growing recognition of the importance of the cereal cyst nematode, Heterodera avenae in winter wheat in China has highlighted the need to better understand local pathotype diversity, as this knowledge is needed to effectively deploy host resistance. Two populations of H. avenae, one each from Xushui and Xingyuang, villages near Zhengzhou, Henan, on the Huang Huai flood plain where 50% of China’s wheat is grown, were typed using 23 standard international differentials and a common local cultivar Wenmai 19. These populations were found to be previously undescribed pathotypes. It is proposed that the pathotype code, Ha43, be applied to the population from Xushui, which was consistently characterised over two seasons and differs from the most similar pathotype, Ha13, by being avirulent in oat cv. Sivan and wheat cvv. Loros and Iskamish K-2-light. Wenmai 19 was found to be susceptible to both populations. Australasian Plant Pathology Society 2010
29 citations
TL;DR: Cyst nematodes obtained from soil samples and plant samples at these four locations differed from those of H. avenae and had uniform morphological and molecular characteristics, and indicated that the four populations were H. filipjevi, a member of the 'Heterodera avenae Group' of cereal cyst Nematodes.
Abstract: During a survey for cereal cyst nematodes from May to June of 2009, cyst nematodes were detected in four wheat-growing areas (Liying, Xuchang, Weihui, and Yanjing) of Henan Province, China The main wheat cultivar affected was Wenmai No4 Almost 53 million ha of winter wheat are grown in Henan Province and 73% of the fields surveyed were found to be infested with Heterodera avenae (2) The affected wheat fields had stunted patches Stunted seedlings had chlorotic or necrotic lower leaves, few or no tillers, and bushy, light brown roots leading to typical witches'-broom symptoms resulting from increased rootlet emergence at the nematode invasion sites Individual roots had a knotted appearance Cyst nematodes obtained from soil samples and plant samples at these four locations differed from those of H avenae and had uniform morphological and molecular characteristics Cysts were lemon shaped and bifenestrate, with an underbridge and strongly developed bullae The lateral field of second-stage juveniles (J2) consisted of four incisures These characteristics indicated that the four populations were H filipjevi, a member of the 'H avenae Group' of cereal cyst nematodes (1) Key morphological features were determined for cysts and J2 Cysts (n = 15) had the following characteristics, in addition to those described above: light brown color; bifenestrate vulval cone with horseshoe-shaped fenestrate; body length (not including the neck) ranged from 690 to 790 μm (mean of 750 μm); body width ranged from 410 to 640 μm (mean of 540 μm); neck length ranged from 86 to 100 μm (mean of 96 μm); fenestrate length of 59 to 70 μm (mean of 677 μm) and width of 313 to 367 μm (mean of 352 μm); underbridge length from 59 to 71 μm (mean of 68 μm); and vulval slit from 69 to 86 μm (mean of 79 μm) J2 (n = 10) had the following characteristics: body length ranged from 540 to 580 μm (mean of 550 μm); stylet length from 225 to 245 μm (mean of 235 μm) with anchor-shaped basal knobs; tail length of 525 to 625 μm (mean of 577 μm); and hyaline terminal tail ranged from 32 to 39 μm (mean of 338 μm) The tail had a sharp terminus Amplification of the rDNA-internal transcribed spacer (ITS) region with primers TW81 and AB28 yielded a PCR fragment of 1,054 bp (3) Amplification of the D2/D3 fragments of the 28S RNA with universal primers D2A (5'-ACA AGT ACC GTG AGG GAA AGT TG-3') and D3B (5'-TCG GAA GGA ACC AGC TAC TA-3') yielded a PCR fragment of 782 bp Digestion patterns of the ITS PCR fragments with AluI, CfoI, HifI, SatI, PstI, RsaI, TaqI, and Tru9I showed restriction profiles identical to that of H filipjevi (3,4) Four ITS sequences (GU083595, GU083596, HM147944, and HM147945) and four D2D3 sequences (GU083592, GU083593, GU083594, and GU083597) from nematode samples collected in Liying, Xuchang, Weihui, and Yanjing, respectively, were submitted to GenBank These sequences exhibited 994% similarity with that of H filipjevi isolates from Germany (AY148400), Italy (AY347922), Russia (AY148401), Spain (AY148399), Tadzhikistan (AY148402), Turkey (AY148398 and AY148397), the United Kingdom (AY148403 and AF274399), and the United States (GU079654) To our knowledge, this is the first report of H filipjevi in China References: (1) Z A Handoo J Nematol 34:250 2002 (2) D L Peng et al Proc 1st Workshop Internat Cereal Cyst Nemat Initiative, Antalya Turkey, p 29, 2009 (3) S A Subbotin et al Nematology 1:195, 1999 (4) G Yan and R W Smiley Phytopathology 100:216, 2010
24 citations
TL;DR: The detection of H. filipjevi was reported at a site in Henan Province that was not included in any previous study or report and all morphological data and characters were consistent with H. FilipJevi.
Abstract: Cereal cyst nematode (CCN) is now recognized as a widespread and often damaging parasite of wheat in China. Only Heterodera avenae has been reported in China (4). However, molecular analysis of four samples from Beijing and one from Shanxi Province indicated genetic differences from H. avenae and other named species (3). Here we report the detection of H. filipjevi at a site in Henan Province that was not included in any previous study or report. The infested crop was rainfed winter wheat (Triticum aestivum) cv. Wenmai 19 in a field near Banpopu Village in Xuchang County (34.0447°N, 113.7415°E) with a long-established maize-wheat semiannual crop rotation. During the winter growing season, the crop was patchy with uneven growth and cyst nematode females were observed on the roots. In June 2009, soil was collected and mature cysts were extracted for morphological and molecular identification. Cysts were also kept at 4°C for 2 months and then incubated in shallow water at 15°C for a month to obtain second-stage juveniles (J2). Measurements (range; mean ± sd) of 10 cysts were body length including neck (569 to 786 μm; 699 ± 56), body width (403 to 600 μm; 523 ± 55), length:width ratio (1.3 to 1.5; 1.3 ± 0.1), neck length (61 to 125 μm; 106 ± 19) and width (49 to 83 μm; 69 ± 13), fenestra length (52 to 59 μm; 57 ± 2.9) and width (24.5 to 34.4; 27.9 ± 3.5), underbridge (64 to 101 μm; 85 ± 10), and vulval slit (7.4 to 10.0 μm; 9.6 ± 1.0). Lemon-shaped cysts were brown with a surface zigzag pattern. The vulval cone was bifenestrate with horseshoe-shaped semifenestra, with heavy underbridge and many bullae. The J2 (n = 22) measurements were body length (496 to 590 μm; 552 ± 24), body width (20.0 to 23.8; 21.5 ± 0.9), stylet (22.8 to 25.3; 24.0 ± 1.0) with anchor-shaped basal knobs, tail (47 to 64; 61.6 ± 4.4), and hyaline tail terminus (32 to 43; 40.2 ± 3.0). The J2 had up to four lateral lines, but the inner two were often the only lines clearly visible, and the shape of the stylet knobs, tail, and tail terminus were consistent with H. filipjevi. All morphological data and characters were consistent with H. filipjevi (1). Specimens have been lodged with the Australian National Insect Collection. DNA from single cysts was extracted to amplify the internal transcribed spacer region of rDNA by PCR with forward primer TW81 (5'-GTTTCCGTAGGTGAACCTGC-3') and reverse primer AB28 (5'-ATATGCTTAAGTTCAGCGGGT-3') (2). The PCR product was sequenced (Genbank Accession No. HM027892) and digested by restriction enzymes (AluI, CfoI, HaeI, HinfI, PstI, RsaI, TaqI, and Tru9I) to obtain restriction fragment length polymorphism profiles (2). Profiles for the Xuchang population consistently matched those published for H. filipjevi and were distinct from those of H. avenae and other species (3). Phylogenic analysis of the sequence further indicated conspecificity with H. filipjevi. These morphological and molecular data confirmed that the specimens from Xuchang were H. filipjevi, which represents the first detection of H. filipjevi in China, and extends the known distribution of the species from Europe, North America, South Asia, and West Asia to East Asia. This finding adds complexity to the management of CCN in China, especially for control by host resistance, which now must consider both species and pathotype diversity. References: (1) Z. A. Handoo. J. Nematol. 34:250, 2002. (2) S. A. Subbotin et al. Nematology 2:153, 2000. (3) S. A. Subbotin et al. Nematology 5:515, 2003. (4) H. X. Yuan et al. Australas. Plant Pathol. 39:107, 2010.
24 citations
TL;DR: In this paper, the inheritance and map location of the CCN resistance locus Qcre.pau-1A was used for studying the inheritance of the resistance gene and to identify the major gene with 26% contribution to the overall phenotypic variance.
Abstract: Triticum monococcum, the diploid A genome species, harbours enormous variability for resistance to biotic stresses. A spring type T. monococcum acc. 14087 was found to be resistant to Heterodera avenae (cereal cyst nematode, CCN). A recombinant inbred line population (RIL) developed by crossing this accession with a CCN susceptible T. boeoticum acc. 5088 was used for studying the inheritance and map location of the CCN resistance. Based on composite interval mapping two QTL, one each on chromosome 1AS and 2AS, were detected. The QTL on 1A, designated as Qcre.pau-1A, appeared to be a major gene with 26% contribution to the overall phenotypic variance whereas the QTL on 2A designated as Qcre.pau-2A contributed 13% to total phenotypic variation. Qcre.pau-1A is novel, being the only CCN resistance gene mapped in any ‘A’ genome species and none of the other known genes have been mapped on chromosome 1A. The QTL Qcre.pau-2A might be allelic to Cre5, a CCN resistance gene transferred from Ae. ventricosa and mapped on 2AS. The Qcre.pau-1A was transferred to cultivated wheat using T. durum cv. PBW114 as the bridging species. Selected CCN resistant F8 lines showed introgression for the molecular markers identified to be linked with CCN resistance locus Qcre.pau-1A. Thus, this gene alone could impart complete resistance against CCN. These introgression lines can be used for marker-assisted transfer of Qcre.pau-1A to elite wheat cultivars.
22 citations
01 Oct 2010
TL;DR: This dissertation aims to provide a history of hand-magnifying lens technology in the United States and investigates its applications in the fields of agriculture, medicine, and nursing.
Abstract: Published October 2010 A more recent revision exists Please check for up-to-date information in the OSU Extension Catalog: http://extensionoregonstateedu/catalog
16 citations
Journal Article•
TL;DR: Analysis of microsatellite markers linked with resistant genes revealed that Cre3 gene located on chromosome 2DL, provided high levels of resistance to CCN in wheat genotypes using Xgwm301 marker, and there was a significant association between CCN resistance with Cre1 locus which explained 12% of the phenotypic variation in CCN infection.
Abstract: Cereal cyst nematode (CCN: Heterodera avenae Woll) causes a significant damage to wheat yield in the Kingdom of Saudi Arabia. Wheat cultivar Yecora Rojo and advanced lines derived from the cross between Yecora Rojo and local line (Sama) were sown in a field infected with CCN. Microsatellite markers linked to Cre1, Cre3, Cre5, Cre8, and CreY genes were used in this study. In addition, the presence of the peroxidase genes in wheat lines was investigated. Three groups of peroxidase genes (TaPrx111-A, TaPrx112-D, and TaPrx113-F) were found to be greatly induced by cereal cyst nematode in the resistance wheat line. In particular, parenchyma cells, where the nematode starts its feeding, were hyper-reactive to some probes belonging to (TaPrx112-D, and TaPrx113-F) groups. The field data showed significant differences in yield performance and CCN score. Four local lines were scored as resistant (KSU114, KSU118, KSU119 and L11-21).The highest grain yield was obtained from local lines KSU 110, KSU 118 and L11-21 compared to the check variety Yecora Rojo. Analysis of microsatellite markers linked with resistant genes revealed that there were significant differences in the presence of genes. Moreover, the results indicated that Cre3 gene located on chromosome 2DL, provided high levels of resistance to CCN in wheat genotypes using Xgwm301 marker. Also, there was a significant association between CCN resistance with Cre1 locus which explained 12% of the phenotypic variation in CCN infection. Gene-specific primer pairs for amplification of peroxidase genes revealed the presence of the TaPrx113-F peroxidase gene in all wheat genotypes. Moreover, cultivar Yocora Rojo and advanced line KSU 119 had TaPrx112-D peroxidase gene. On the other hand, the other wheat lines lacked the presence of TaPrx112-D peroxidase gene. The advanced line KSU 119 was resistant to CCN and contained Cre1, which was absent in susceptible cultivar Yecora Rojo. Therefore, the presence of peroxidase genes alone did not explain differences among wheat genotypes for CCN resistance. Amplification conditions for Cre3 and Cre1 loci were optimized, and used in marker-assisted selection to identify CCN-resistant wheat in the Saudi wheat cultivars. Data of this study emphasized the potentiality of identifying a highly productive CCN resistant cultivar.
12 citations
TL;DR: It is suggested that future research should focus on developing locally adapted resistant cultivars and examining factors that determine the efficacy of natural biocontrol in order to examine the effect of crop rotations.
Abstract: Cereal cyst nematode (Heterodera avenae) population densities were determined in spring cereals after harvest in three high-altitude villages in Qinghai, China in order to examine the effect of crop rotations. Two villages were sampled intensively to allow examination of between-field spatial variation. The previous season’s crop, including fields where two host crops had been grown in succession, did not appear to influence the final nematode density. A high degree of variation in population density and significant spatial variation appeared to be strongly influenced by the occurrence of hyperparasites, thus masking any possible crop rotation effects. Nevertheless, a third of the fields had final egg densities of greater than 10 eggs/g soil, creating a risk of yield loss if an intolerant host was to be grown in the next year. From the findings, it is suggested that future research should focus on developing locally adapted resistant cultivars and examining factors that determine the efficacy of natural biocontrol.
7 citations
TL;DR: Madzhidov et al. as mentioned in this paper determined the pathotype group of the Heterodera filipjevi population and resistance of H. avenae pathotypes against wheat genotypes.
Abstract: *Summary Determination of the pathotype group of Heterodera filipjevi (Madzhidov, 1981) population and resistance of H. populations against wheat genotypes The international pathotype differential lines were used to determine the pathotype group of Heterodera filipjevi (Madzhidov, 1981) Stelter population collected from Yozgat province, Turkey. The reaction of H. filipjevi Yozgat population on the differential lines indicated they were different than the other 5 known H. filipjevi pathotypes. Futherwork was conducted with these H. filipjevi populations to assess the usabilitiy of known published Cereal Cyst Nematode (CCN) resistance genes against a closely related species and pathotypes of Heterodera avenae Wollenweber, 1924. Several of these wheat lines known to possess resistance against H. avenae pathotypes and also the Haymana H. filipjevi populations did not exhibit resistance against H. filipjevi Yozgat populations.
01 Jan 2010
TL;DR: Final population densities (Pf) of H. avenae were positively correlation with Pi, whereas reproduction factors (Rf) were negatively correlated with Pi on both wheat cultivars, and durum wheat was more sensitive than bread wheat to the nematode.
Abstract: Three trials were conducted to asses the effects of three levels of initial population densities (Pi) of Heterodera avenae (15.3, 27.6, 40.4 eggs and juveniles/g soil) on growth and yield of two wheat cultivars (’Sham 3’ of durum wheat and ’Sham 6’ of bread wheat) and nematode reproduction, under field conditions in North East Syria, during the growing season 2006-2007. Reduction of yield components of both wheat cultivars increased with the increase of Pi of H. avenae and reached maxima of 56.6% and 49.6% in grain yield and 49.5% and 44.6% in straw yield in durum and bread wheat, respectively, at the greatest initial population density of 40.4 eggs and juveniles/g soil. A similar trend was observed for the reduction of plant height in both cultivars. Durum wheat was more sensitive than bread wheat to the nematode. Significant negative linear regressions were observed between Pi of H. avenae and yield components of both wheat cultivars. Final population densities (Pf) of H. avenae were positively correlated with Pi, whereas reproduction factors (Rf) were negatively correlated with Pi on both wheat cultivars.
Journal Article•
TL;DR: There was negative correlation between the plant growth parameters and the nematode infestation, observed during the foliar application of different molecules, thus increases the tolerance in plants, against H. avenae.
Abstract: The investigations were carried out to evaluate the response of three synthetic elicitor molecules, namely, DL-â-amino-n butyric acid (BABA) (@ 2000, 4000, 6000 and 8000 μg/ml), Jasmonic acid (JA) and Salicylic acid (SA) (@ 25, 50, 100 and 200 μg/ml) as foliar application on wheat (Triticum aestivum) crop against the cereal cyst nematode, Heterodera avenae. In general, the plant growth parameters (shoot length, shoot weight, root length, root weight) of wheat plant increased with an increase in the concentration of elicitor molecules. However, the plant growth showed variable responses irrespective of the dosage and the type of elicitor molecules. There was negative correlation between the plant growth parameters and the nematode infestation, observed during the foliar application of different molecules, thus increases the tolerance in plants, against H. avenae. Among the three elicitor molecules, BABA @ 8000 μg/ml was highly effective in reducing the nematode penetration (by 74%) and further development of H. avenae and increase in plant growth parameters, followed by JA and SA @200 μg/ml. Thus, these molecules could be further utilized under microplot/field conditions for the management of H. avenae in wheat.
Journal Article•
TL;DR: The rich genetic diversities in CCN populations from Jiangsu and other provinces in China were demonstrated in this study and the close relationship between Zhengzhou populations and H. australis was revealed.
Abstract: ITS region of ribosomal DNA was amplified from 15 populations of cereal cyst nematodes ( CCN) on wheat from 4 districts ( Xuzhou,Suqian,Lianyungang and Yancheng) of Jiangsu Province,China. The ITS-RFLP patterns revealed that all populations showed the same fragments after digestion with 8 restriction enzymes. The Jiangsu populations not only obtained the same patterns as the "B" type ( Indian populations) by AluⅠand RsaⅠdigestions,but also the "C" type by HinfⅠand Tru9Ⅰ digestions which were specialized for the Chinese populations. The phylogeny trees were constructed by Neighbor-Joining ( MEGA 4. 0) based on ITS sequences and revealed that all of Jiangsu populations were grouped with the species from Heterodera avenae complex,which was one of the branches of the H. avenae group. Most of the Jiangsu populations were genetically closed to the Russian and German populations of H. pratensis. Comparisons of ITS sequences between Jiangsu populations with other CCN populations from China and abroad revealed the close relationship between Zhengzhou populations and H. australis. The regional identities were clearly showed in the populations from Qinghai Province and Zhengzhou,Henan Province. The rich genetic diversities in CCN populations from Jiangsu and other provinces in China were demonstrated in this study.
01 Oct 2010
TL;DR: Genes encoding cytosolic forms of APX were induced in roots of both lines in response to nematode infection and this induction took place both earlier and with greater intensity in the resistant line than in the susceptible one, and it was also higher in the root area at the site of nematodes attachment.
Abstract: Changes in ascorbate peroxidase (APX) enzyme activity in response to nematode (Heterodera avenae) attack were studied in roots of three hexaploid wheat lines carrying Cre2, Cre5, or Cre7 nematode resistance genes and the susceptible Triticum aestivum cv. Anza. A spectrophotometric analysis was carried out with root extracts of infected plants 4, 7, 11, and 14 days after nematode inoculation using uninfected plant as control. APX induction in infected resistant genotypes was similar and higher than in the susceptible control. The introgression wheat/Aegilops ventricosa H-93-8 line, carrying the Cre2 gene, and its parental line H-10-15 as susceptible control were used to analyze whether this increase of activity was correlated with the induction of APX gene expression. Genes encoding cytosolic forms of APX were induced in roots of both lines in response to nematode infection. This induction took place both earlier and with greater intensity in the resistant line than in the susceptible one, and it was also higher in the root area at the site of nematode attachment.