Observations On Fungal Parasites of Females and Eggs of the Cereal Cyst-Nematode, Heterodera Avenae, and Other Cyst Nematodes

Nematologica ◽  
1977 ◽  
Vol 23 (2) ◽  
pp. 193-201 ◽  
Author(s):  
D.H. Crump ◽  
B.R. Kerry
Keyword(s):  
Cyst Nematode ◽  
Cereal Cyst Nematode ◽  
Heterodera Avenae ◽  
Cyst Nematodes ◽  
Fungal Parasites

Electrophoresis and biotest studies on some populations of cereal cyst nematode, Heterodera spp. (Tylenchida: Heteroderidae)

Nematology ◽  
2004 ◽  
Vol 6 (6) ◽  
pp. 857-865 ◽  
Author(s):  
Stig Andersson ◽  
Ricardo Holgado ◽  
Christer Magnusson ◽  
Janet Rowe
Keyword(s):  
Isoelectric Focusing ◽  
Banding Pattern ◽  
Cyst Nematode ◽  
Cereal Cyst Nematode ◽  
Heterodera Avenae ◽  
Cyst Nematodes ◽  
Norwegian Population ◽  
Host Spectrum ◽  
Cereal Cultivars

AbstractProtein variability of 27 populations of cyst nematodes belonging to the Heterodera avenae complex were studied using isoelectric focusing (IEF). Sixteen Norwegian populations were compared with standard populations of H. avenae, H. filipjevi, H. mani and H. arenaria. Norwegian populations were also tested for pathotype on selected cereal cultivars. Based on differences in the protein banding pattern, eight clusters of populations could be recognised. Nine Norwegian populations grouped together with H. avenae standards. The three Swedish populations: Knislinge, Ringsåsen and Våxtorp, previously classified as H. avenae, differed from this species, from H. filipjevi and from each other. Four Norwegian populations clustered together with the Våxtorp population. Two Norwegian populations formed a cluster together with a Swedish H. filipjevi standard. The Norwegian population Brekstad differed from all other populations, as did the standards of H. mani and H. arenaria. Pathotype testing of the Norwegian populations identified ten populations as H. avenae pathotype Ha 11, while three were close to pathotype Ha 12. The two H. filipjevi populations were close to the Swedish pathotype west. The Brekstad population differed from all others also in host spectrum. This population and the Våxtorp-group demonstrate a complexity within the Norwegian cereal cyst nematodes that merits further investigation.

scholarly journals Incidence of Cereal Cyst Nematode Prevailing in Wheat-rice Growing Regions of Punjab Province, Pakistan

2020 ◽  
Author(s):  
M. Imran Hamid ◽  
M. Usman Ghazanfar ◽  
M. Qaiser Naeem Khan ◽  
Zaib ul Hasan ◽  
Saman Aslam
Keyword(s):  
Nematode Species ◽  
Cyst Nematode ◽  
Soil Samples ◽  
Rice Fields ◽  
Cereal Cyst Nematode ◽  
Heterodera Avenae ◽  
Cyst Nematodes ◽  
Population Densities ◽  
Punjab Province ◽  
Rice Monoculture

Background: Cereal Cyst Nematodes (CCN) are prevailing in all type of agricultural lands and responsible for enormous losses of cereal crops. The understandings on population densities and management of these nematode are required to improve crop health and productivity.Methods: A study was designed to assess the incidence of cereal cyst nematodes in wheat and rice monoculture cropping regions of eight districts of Punjab province, viz., Jhang, Khushab, layyah, Hafizabad, Sheikhupura, Narowal, Gujranwala and Sargodha in Pakistan. Population densities of cereal cyst nematodes were studied by extracting the cysts and second stage juveniles from soil samples and identified the nematode species. Result: The CCNs were found in 80% of the total 250 samples collected from wheat and rice monoculture fields of at least one crop. In the soil samples collected from wheat fields, an average of 7 to 38 cysts/100g of dry soil with eggs and J2 population of 142-771 were recorded. Whereas from the soil samples of rice fields, 17 to 25 cysts/100g soil were found with 345 to 508 eggs and juveniles. Among the wheat fields, the lowest incidence of 5.5% was recorded in kot–momin and highest incidence of 16.88% was recorded in Silanwali tehsils of Sargodha region. In rice fields, 24.69 to 27.00% incidence of CCNs was noticed in soil samples of various surveyed regions. Three different species of Heterodera genus were morphologically identified from the collections. The species includes Heterodera oryzae, Heterodera avenae and Heterodera graminophila. H. oryzae was more abundant in rice growing regions while H. avenae and H. graminophila were present dominantly in wheat growing regions. This study provides an inclusive information regarding cereal cyst nematode densities and species in wheat-rice growing regions of Punjab province of Pakistan.

Effects of fungal parasites on cereal cyst nematode (Heterodera avenae Woll.) from naturally infested soil—a scanning electron microscopy study

1991 ◽  
Vol 37 (3) ◽  
pp. 218-225 ◽  
Author(s):  
L. V. Lopez-Llorca ◽  
G. H. Duncan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Early Stage ◽  
Cyst Nematode ◽  
Infection Process ◽  
Cereal Cyst Nematode ◽  
Heterodera Avenae ◽  
Infested Soil ◽  
Fungal Parasites ◽  
Scanning Electron

The effects of fungal endoparasites, attacking the eggs of the cereal cyst nematode Heterodera avenae, and details of the infection process were studied by low-temperature scanning electron microscopy. Some female nematodes, even young ones containing no eggs, were colonized by fungi. Spores and hyphae similar to those of Nematophthora gynophila were found in infected specimens. Fungi colonized both roots and nematodes. In early stages of infection, fungi developed within the female nematode between the organs, presumably using the female's body as a food source. In some immature females, the fungi appeared to have destroyed the uterus. In old females, appressoria of Verticillium spp., including V. chlamydosporium, penetrated the eggs they contained and progressively destroyed their contents until the egg shell was filled with hyphae and spores. Only rarely were second-stage juveniles within eggs infected by these fungi. Fungal infection of eggs, which arrests their development at an early stage, therefore occurs predominantly in females rather than in newly formed cysts. Key words: Heterodero avenae, fungal parasites, naturally infested soil, scanning electron microscopy.

Influence of cereal cyst nematode (Heterodera avenae) on wheat yields in South Australia

1981 ◽  
Vol 21 (112) ◽  
pp. 516 ◽  
Author(s):  
AD Rovira ◽  
PG Brisbane ◽  
A Simon ◽  
DG Whitehead ◽  
RL Correll
Keyword(s):  
Wheat Variety ◽  
South Australia ◽  
Field Trials ◽  
Cyst Nematode ◽  
Analysis Of Covariance ◽  
Cereal Cyst Nematode ◽  
Heterodera Avenae ◽  
Yield Increase ◽  
Significant Yield ◽  
Yield Responses

Significant yield responses of up to 0.9 t/ha were obtained with the nematicides aldicarb and dibromochloropropane in seven of eleven field trials with the wheat variety, Condor. Both nematicides reduced the numbers of white cysts of Heterodera avenae on the roots of wheat. With aldicarb the increase in wheat yields varied directly as the decrease in white cysts: dibromochloropropane gave similar increases in yield as aldicarb with a greater reduction in cyst numbers. There was no yield increase with either nematicide when cereal cyst nematode was not present. An analysis of covariance indicated that over all the sites 64% of the increase in yield due to aldicarb could be explained in terms of cysts of cereal cyst nematode.

scholarly journals Discovery of Heterodera filipjevi in Washington and Comparative Virulence with H. avenae on Wheat

Plant Disease ◽  
2015 ◽  
Vol 99 (3) ◽  
pp. 376-386 ◽  
Author(s):  
Richard W. Smiley ◽  
Guiping Yan
Keyword(s):  
United States ◽  
The United States ◽  
Cyst Nematode ◽  
Cereal Cyst Nematode ◽  
Heterodera Avenae ◽  
Management Guidelines ◽  
Polymerase Chain ◽  
Species Specific ◽  
Eastern Washington ◽  
Cyst Morphology

The cereal cyst nematode Heterodera avenae suppresses wheat production in the western United States. A second species of cereal cyst nematode, H. filipjevi, was identified in eastern Oregon during 2008. This paper reports the discovery of H. filipjevi–infested fields in eastern Washington, thereby extending the known distribution of H. filipjevi in the United States. The identity of H. filipjevi was determined and confirmed by species-specific polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism (RFLP), sequencing, and cyst morphology. Soils that were collected from naturally infested fields in Washington were used to compare the virulence of H. avenae and H. filipjevi on six spring wheat cultivars under controlled-environment conditions. Noninfested soils from nearby fields were used as controls. Cultivars Ouyen and WB Rockland were resistant to H. avenae and susceptible to H. filipjevi. Cultivars Sönmez and SY Steelhead were resistant to H. filipjevi and susceptible to H. avenae. Cultivars Louise and WB 936 were susceptible to both species. The resistance of SY Steelhead to ‘H. avenae’, reported in a previous paper, is corrected as resistance to H. filipjevi due to an earlier misidentification of H. filipjevi. Management guidelines that include crop rotations and resistant cultivars are presented. Discovery of additional infestations of H. filipjevi are anticipated when DNA-based tests become used routinely in commercial diagnostic laboratories.

Resistance of wheat, barley and oat to Heterodera avenae in the Pacific Northwest, USA

Nematology ◽  
2011 ◽  
Vol 13 (5) ◽  
pp. 539-552 ◽  
Author(s):  
Richard W. Smiley ◽  
Guiping Yan ◽  
John N. Pinkerton
Keyword(s):  
Resistance Gene ◽  
Pacific Northwest ◽  
Resistance Genes ◽  
Cyst Nematode ◽  
Cereal Cyst Nematode ◽  
Heterodera Avenae ◽  
Wheat Cultivars ◽  
The Pacific ◽  
The Usa ◽  
Breeding Programmes

Abstract The cereal cyst nematode, Heterodera avenae, occurs in at least seven western states of the USA and reduces grain yield in localised regions and in selected crop management systems. Virulence phenotypes for H. avenae populations in North America have not been reported. Nine individual assays in six experiments were conducted to determine the reactions of barley, oat and wheat cultivars to five H. avenae populations in the Pacific Northwest (PNW) states of Idaho, Oregon and Washington. Three populations were evaluated for virulence to 23 entries of the 'International Test Assortment for Defining Cereal Cyst Nematode Pathotypes', plus selected local cultivars and entries representing a greater diversity of resistance genes. The virulence phenotype(s) for populations of H. avenae in the PNW did not correspond to any of the 11 pathotypes defined by the Test Assortment. Five PNW populations exhibited affinities with Group 2 but were not defined by pathotypes Ha12 and Ha22. Reproduction was prevented or greatly inhibited by barley carrying the Rha3 resistance gene and by most carriers of Rha2 resistance, and by selected oat cultivars with multigenic resistance. Wheat cultivars carrying the Cre1 resistance gene were highly effective in suppressing H. avenae reproduction. Current PNW wheat cultivars do not carry the Cre1 resistance gene. Crosses between Ouyen, an Australian bread wheat with Cre1 resistance, and several PNW wheat cultivars were resistant. The CreR gene also prevented H. avenae reproduction in the trial where it was tested. Intermediate levels of reproduction occurred on wheat cultivars carrying the Cre5, Cre7 and Cre8 resistance genes, each of which was considered useful for pyramiding into cultivars with Cre1 resistance. This research identified genetic resources of value in PNW cereal crop breeding programmes.

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