scholarly journals Fungi associated with cysts of Globodera rostochiensis, G. pallida, and Heterodera schachtii; and egg masses and females of Meloidogyne hapla in Belgium

2005 ◽  
Vol 79 (2) ◽  
pp. 63-69 ◽  
Author(s):  
Q. Yu ◽  
J. Coosemans
Keyword(s):  
Solanum Tuberosum ◽  
Lycopersicon Esculentum ◽  
Sugar Beet ◽  
Fusarium Oxysporum ◽  
Beta Vulgaris ◽  
Globodera Rostochiensis ◽  
Heterodera Schachtii ◽  
Meloidogyne Hapla ◽  
Egg Masses ◽  
Predominant Species

Cysts of Heterodera schachtii from sugar-beet (Beta vulgaris) fields and cysts of Globodera rostochiensis and G. pallida from potato (Solanum tuberosum) fields in northern Belgium, as well as egg masses and females of Meloidogyne hapla from a tomato (Lycopersicon esculentum) field in the Flemish-Brabant province, Belgium, were collected and examined for the presence of fungi. Of the total of 374 cysts of H. schachtii, 57.7% were colonized by one or more of 18 different species of fungi, all of which were from the genra Acremonium, Chaetomium, Cylindrocarpon, Fusarium, Gliocladium, Humicola, Mariannaea, Nematophthora, Periconia, Phoma, and Verticillium, and 45.3% of the 726 cysts of Globodera spp. were colonized by one or more of 18 different species, from the same gene. Of the 160 egg masses of M. hapla, 32% were colonized by one or more of 18 species of the genra Arthrobotrys, Cylindrocarpon, Fusarium, Monacrosporium, Paecilomyces, Phoma, Plectosphaerella, and Verticillium, while 31% of the 160 females were colonized by 12 species, from the same gene except Paecilomyces and Plectosphaerella. Fusarium oxysporum was by far the predominant species in both the cyst and root-knot nematodes. A black yeast-like fungus was found in cysts.

scholarly journals Fungi associated with egg masses and females of plant parasitic nematode Meloidogyne incognita (Nematoda: Heteroderidae)

2018 ◽  
Vol 44 (3) ◽  
pp. 373-378 ◽  
Author(s):  
Mehmet Karakas
Keyword(s):  
Lycopersicon Esculentum ◽  
Fusarium Oxysporum ◽  
Meloidogyne Incognita ◽  
Parasitic Nematode ◽  
Plant Parasitic Nematode ◽  
Central Anatolia ◽  
Egg Masses ◽  
Predominant Species ◽  
Lycopersicon Esculentum Mill ◽  
Plant Parasitic

Egg masses and females of Meloidogyne incognita from a tomato (Lycopersicon esculentum Mill. cv. Falcon) field from Central Anatolia of Turkey, were collected and examined for the presence of fungi. Of the 138 egg masses of M. incognita 35.5% were colonized by one or more of 9 species of genera Arthrobotrys, Cylindrocarpon, Fusarium, Paecilomyces, Plectosphaerella, Rhizoctonia and Verticillium while 31.8% of the 138 females were colonized by 6 species, from the same genera except Paecilomyces and Plectosphaerella. Fusarium oxysporum was by far the predominant species in both the egg masses and females of M. incognita.

scholarly journals Induction of Beet-Cyst Nematode Suppressiveness by the Fungi Dactylella oviparasitica and Fusarium oxysporum in Field Microplots

2006 ◽  
Vol 96 (8) ◽  
pp. 855-859 ◽  
Author(s):  
Rabiu Olatinwo ◽  
James Borneman ◽  
J. Ole Becker
Keyword(s):  
Sugar Beet ◽  
Fusarium Oxysporum ◽  
Cyst Nematode ◽  
Heterodera Schachtii ◽  
Field Soil ◽  
Degree Days ◽  
Population Densities ◽  
Time Points ◽  
Second Stage ◽  
Greenhouse Study

The ability of Dactylella oviparasitica and Fusarium oxysporum to suppress Heterodera schachtii numbers was examined in field microplots. Fungi were individually added to fumigated field soil that was seeded with sugar beet. Four weeks later, soils were infested with H. schachtii second-stage juveniles (J2). At two harvests, 11 weeks and 19 weeks (1,469 and 2,547 degree days (base 8°C), respectively) after nematode-infestation, H. schachtii cyst and egg numbers were assessed. At both time points, D. oviparasitica reduced H. schachtii population densities to those in the naturally suppressive soil, even when additional H. schachtii J2 were added to the microplots after the first harvest. Although F. oxy-sporum did not alter H. schachtii population densities after 11 weeks, significant reductions were detected after 19 weeks. The sustainability of the H. schachtii suppressiveness created by single applications of the fungi at the beginning of the microplot trials was further examined in a greenhouse study. Soil collected at the completion of the microplot trials was potted and seeded with sugar beet. Four weeks later, each pot was infested with H. schachtii J2. Approximately 16 weeks (1,389 degree days) after seeding, the D. oviparasitica-amended soil produced greater fresh root weights and considerably smaller nematode population densities than the nonamended control.

Using a selective fast turn-around bioassay for population density determination of Heterodera schachtii

Nematology ◽  
2013 ◽  
Vol 15 (7) ◽  
pp. 809-819 ◽  
Author(s):  
Annabell Meinecke ◽  
Andreas Hermann ◽  
Andreas Westphal
Keyword(s):  
Sugar Beet ◽  
Globodera Pallida ◽  
Heterodera Schachtii ◽  
Soil Types ◽  
Meloidogyne Hapla ◽  
Cyst Nematodes ◽  
Soil Extraction ◽  
Easy Method ◽  
Wide Range ◽  
Field Samples

In Central Europe, Heterodera schachtii is kept below threshold levels by cover-cropping with resistant crucifers and crop rotation with non-hosts. Determining population densities of H. schachtii in soil is critical when implementing resistant and tolerant sugar beet cultivars in integrated pest management (IPM) programmes. Soil extraction of the cysts followed by egg counts or extraction of the second-stage juveniles (J2) facilitated by the chemical stimulant acetox can be unsatisfactory in mixed field populations of cyst nematodes. In contrast to H. schachtii, nematodes typically present in sugar beet soils, e.g., Globodera pallida, G. rostochiensis, H. avenae, H. filipjevi, Meloidogyne hapla, M. incognita and Pratylenchus penetrans, rarely penetrated radish roots. In this bioassay, equivalents of 50 g of soil dry weight were adjusted to 10-20% moisture, seeded with Raphanus sativus cv. Saxa 3, and incubated at a day-night (16:8 h) cycle of 28/23°C for 4 days before J2 in radish roots were enumerated. In different soil types, penetration by H. schachtii reflected the inoculation levels. When inoculated with mixes of H. schachtii with H. avenae or H. filipjevi, counts of H. schachtii were similar to those in soils with H. schachtii only. When comparing three methods in three soils spiked with H. schachtii cysts, the bioassay and the extraction method were lightly impacted by the soil texture but results of the acetox method varied with texture. When implemented for field samples from Franconia, the radish bioassay and the acetox method provided results related to cyst and egg extraction data. The radish bioassay provided a quick and easy method for quantifying H. schachtii in the presence of other nematode species in a wide range of soil types. Including this assay in IPM programmes may serve as an alternative to standard methods and will improve the decision making in sustainable production systems.

The monoxenic culture of beet eelworm (Heterodera schachtii Schm.) on excised roots of sugar beet (Beta vulgaris L.)

Parasitology ◽  
1964 ◽  
Vol 54 (2) ◽  
pp. 289-293 ◽  
Author(s):  
F. Moriarty
Keyword(s):  
Sugar Beet ◽  
Beta Vulgaris ◽  
Lateral Roots ◽  
Heterodera Schachtii ◽  
Chemical Stimulus ◽  
Adult Males ◽  
Wound Reaction ◽  
Maximum Root ◽  
Research And Education ◽  
Tissue Reactions

A method is described for obtaining sterile second-instar larvae of beet eelworm, Heterodera schachtii Schm., and culturing them to the adult stage on sterile excised roots of sugar beet, Beta vulgaris L. It was shown that beet eelworm is a primary pathogen, for sound uninjured radicles were invaded by larvae, and normal development of adult males and females followed. No females were fertilized, and no eggs were produced, which suggested that parthenogenesis cannot occur. Eelworm development stimulated the production of lateral roots. More adult females developed on radicles inoculated 24 hr. after excision than on radicles inoculated 72 hr. after excision, which may be related to the occurrence of maximum root extension during the first few days after excision. It is suggested that there are two parts in root tissue reactions: a thickening of cell walls as a wound reaction to mechanical injury, and formation of a syncytium in response to a chemical stimulus from the eelworm.I thank my wife for assistance with this work, which was financed by the Sugar Beet Research and Education Committee.

Sugar Beet Nematode (Heterodera Schachtii) Reared On Axenic Beta Vulgaris Root Explants

Nematologica ◽  
1969 ◽  
Vol 15 (1) ◽  
pp. 144-152a ◽  
Author(s):  
Ruth N. JOHNSON ◽  
D.R. Viglierchio
Keyword(s):  
Sugar Beet ◽  
Beta Vulgaris ◽  
Heterodera Schachtii ◽  
Root Explants

Association of a nematode resistance bearing addition chromosome with a recurring leaf intumescence somaclonal variation in sugar beet

Genome ◽  
1991 ◽  
Vol 34 (3) ◽  
pp. 477-485
Author(s):  
M. H. Yu ◽  
L. M. Pakish ◽  
J. W. Saunders
Keyword(s):  
Sugar Beet ◽  
Somaclonal Variation ◽  
Beta Vulgaris ◽  
Chromosome Doubling ◽  
Nematode Resistance ◽  
Heterodera Schachtii ◽  
Regenerated Plants ◽  
Alternative Expression ◽  
Monosomic Addition

Intumescent leaf variants of sugar beet (Beta vulgaris L.) were obtained through callus culture of a monosomic addition that carried resistance to Heterodera schachtii Schm. The frothy pockmarked appearance of the leaf surface was due to hyperplastic growth of the mesophyll and epidermal cells. The epidermis had many malformed stomata. Veins were underdeveloped, but protrusions beneath were pronounced. Intumescence occurred in 20.3% of the regenerated plants and it was heritable to F1 and later progeny. Leaf intumescence is a new phenotype for Beta. About 73.5% of regenerants contained the donor somatic chromosome number, the remainder were doubled or mixoploids, with no chromosome losses apparent. The 38-chromosome intumescent plant represents a dual somaclonal variation, chromosome doubling and leaf intumescence. Progeny of the 19- and 38-chromosome intumescent plants intercrossed or pollinated by diploids or tetraploids had 9, 18, 19, 27, 28, 29, 36, 37, 38, or 39 chromosomes. All intumescent plants were aneuploids with the monosome addition. There were linkages for leaf intumescence (Li), resistance to H. schachtii (Hs), and hypocotyl color (Rpro) on the addition chromosome. The efficacy of Hs remained intact through the in vitro culture and succeeding crosses. The Li-bearing plants manifested depressed growth and markedly reduced seed set. Leaf intumescence was thought to be the alternative expression of galling potential of Beta procumbens Chr. Sm. germ plasm.Key words: somaclonal variation, leaf intumescence, nematode resistance, monosomic addition, Beta vulgaris L.

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