Invasion of non-host plant roots by larvae of the sugarbeet nematode, Heterodera schachtii

1971 ◽  
Vol 16 (6) ◽  
pp. 457-460 ◽  
Author(s):  
Arnold E. Steele
Keyword(s):  
Host Plant ◽  
Plant Roots ◽  
Heterodera Schachtii

Experiments with Cysts of the Potato Eelworm (Heterodera schachtii) of Different Ages

1938 ◽  
Vol 16 (2) ◽  
pp. 67-76 ◽  
Author(s):  
Mary T. Franklin
Keyword(s):  
Host Plant ◽  
Cyst Wall ◽  
Good Yield ◽  
Potato Crop ◽  
Heterodera Schachtii ◽  
Soil Conditions ◽  
Fungal Attack ◽  
Large Numbers ◽  
Different Ages

One of the peculiarities of the eelworm Heterodera schachtii which makes it a very difficult parasite to control is the length of time it can survive in a dormant condition in the soil. In this state the embryonated eggs are protected by the resistant cyst wall, and, in the case of the potato strain of the eelworm, the larvae only hatch in large numbers in the presence of the host plant. On account of this property, land infected with the parasite remains infected even though the host plant is not grown. It is however well known that if “potato sick” land is rested from potatoes for a few years it is then sometimes possible to grow a potato crop giving a fairly good yield and showing little or no sign of sickness in the overground parts. In these cases, however, it is often found that the roots of the plants are heavily infested with eelworm. These and other observations have led to suggestions that other factors may be associated with H. schachtii in giving rise to the condition known as “potato-sickness.” Such factors may be due wholly or in part to soil conditions, climate, fungal attack or the time of attack by the eelworm. In some cases more than one factor may operate in addition to the nematode, and in different cases it is probable that different factors come into play.

scholarly journals Comparative genomics among three cyst nematode species reveals distinct evolutionary histories among effector families and an irregular distribution of effector-associated promoter motifs

2021 ◽  
Author(s):  
Joris J.M. van Steenbrugge ◽  
Sven van den Elsen ◽  
Martijn Holterman ◽  
Jose L. Lozano-Torres ◽  
Vera Putker ◽  
...  
Keyword(s):  
Host Plant ◽  
Reference Genome ◽  
Nematode Species ◽  
Cyst Nematode ◽  
Globodera Pallida ◽  
Heterodera Schachtii ◽  
Cyst Nematodes ◽  
Promoter Regions ◽  
Long Read ◽  
Additional Reference

Potato cyst nematodes (PCNs), an umbrella term used for two species, Globodera pallida and G. rostochiensis, belong worldwide to the most harmful pathogens of potato. Pathotype-specific host plant resistances are an essential handle for PCN control. However, the poor delineation of G. pallida pathotypes hampers the efficient use of available host plant resistances. Long-read sequencing technology allowed us to generate a new reference genome of G. pallida population D383 and, as compared to the current reference, the new genome assembly is 42 times less fragmented. For comparison of diversification patterns of six effector families between G. pallida and G. rostochiensis, an additional reference genome was generated for an outgroup, the beet cyst nematode Heterodera schachtii (IRS population). Large evolutionary contrasts in effector family topologies were observed. While VAPs diversified before the split between the three cyst nematode species, the families GLAND5 and GLAND13 only expanded in PCN after their separation from the genus Heterodera. Although DNA motifs in the promoter regions thought to be involved in the orchestration of effector expression (DOG boxes) were present in all three cyst nematode species, their presence is not a necessity for dorsal gland-produced effectors. Notably, DOG box dosage was only loosely correlated with expression level of individual effector variants. Comparison of the G. pallida genome with those of two other cyst nematodes underlined the fundamental differences in evolutionary history between effector families. Re-sequencing of PCN populations with deviant virulence characteristics will allow for the linking of these characteristics with the composition of the effector repertoire as well as for the mapping of PCN diversification patterns resulting from extreme anthropogenic range expansion.

scholarly journals Community composition of arctic root-associated fungi mirrors host plant phylogeny

2020 ◽  
Vol 96 (11) ◽  
Author(s):  
S S Botnen ◽  
E Thoen ◽  
P B Eidesen ◽  
A K Krabberød ◽  
H Kauserud
Keyword(s):  
Host Plant ◽  
Community Composition ◽  
Plant Species ◽  
Host Plants ◽  
Plant Roots ◽  
Gene Marker ◽  
Rrna Gene ◽  
Phylogenetic Distance ◽  
Gene Markers ◽  
Plant Phylogeny

ABSTRACT The number of plant species regarded as non-mycorrhizal increases at higher latitudes, and several plant species in the High-Arctic Archipelago Svalbard have been reported as non-mycorrhizal. We used the rRNA ITS2 and 18S gene markers to survey which fungi, as well as other micro-eukaryotes, were associated with roots of 31 arctic plant species not usually regarded as mycorrhizal in Svalbard. We assessed to what degree the root-associated fungi showed any host preference and whether the phylogeny of the plant hosts may mirror the composition of root-associated fungi. Fungal communities were largely structured according to host plant identity and to a less extent by environmental factors. We observed a positive relationship between the phylogenetic distance of host plants and the distance of fungal community composition between samples, indicating that the evolutionary history of the host plants plays a major role for which fungi colonize the plant roots. In contrast to the ITS2 marker, the 18S rRNA gene marker showed that chytrid fungi were prevalently associated with plant roots, together with a wide spectrum of amoeba-like protists and nematodes. Our study confirms that arbuscular mycorrhizal (AM) fungi are present also in arctic environments in low abundance.

scholarly journals Identification of potential host plant mimics of CLAVATA3/ESR (CLE)-like peptides from the plant-parasitic nematode Heterodera schachtii

2010 ◽  
Vol 12 (2) ◽  
pp. 177-186 ◽  
Author(s):  
JIANYING WANG ◽  
AMY REPLOGLE ◽  
RICHARD HUSSEY ◽  
THOMAS BAUM ◽  
XIAOHONG WANG ◽  
...  
Keyword(s):  
Host Plant ◽  
Parasitic Nematode ◽  
Plant Parasitic Nematode ◽  
Heterodera Schachtii ◽  
Potential Host ◽  
Plant Parasitic

scholarly journals Imazapic Herbigation for Egyptian Broomrape (Phelipanche aegyptiaca) Control in Processing Tomatoes—Laboratory and Greenhouse Studies

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1182
Author(s):  
Yaakov Goldwasser ◽  
Onn Rabinovitz ◽  
Zev Gerstl ◽  
Ahmed Nasser ◽  
Amit Paporisch ◽  
...  
Keyword(s):  
Host Plant ◽  
Drip Irrigation ◽  
High Rate ◽  
Plant Roots ◽  
Irrigation Systems ◽  
Vast Number ◽  
Tomato Roots ◽  
Wide Range ◽  
Heavy Damage ◽  
Processing Tomatoes

Parasitic plants belonging to the Orobanchaceae family include species that cause heavy damage to crops in Mediterranean climate regions. Phelipanche aegyptiaca is the most common of the Orobanchaceae species in Israel inflicting heavy damage to a wide range of broadleaf crops, including processing tomatoes. P. aegyptiaca is extremely difficult to control due to its minute and vast number of seeds and its underground association with host plant roots. The highly efficient attachment of the parasite haustoria into the host phloem and xylem enables the diversion of water, assimilates and minerals from the host into the parasite. Drip irrigation is the most common method of irrigation in processing tomatoes in Israel, but the delivery of herbicides via drip irrigation systems (herbigation) has not been thoroughly studied. The aim of these studies was to test, under laboratory and greenhouse conditions, the factors involved in the behavior of soil-herbigated imazapic, and the consequential influence of imazapic on P. aegyptiaca and tomato plants. Dose-response Petri dish studies showed that imazapic does not impede P. aegyptiaca seed germination and non-attached seedlings, even at the high rate of 5000 ppb. Imazapic applied to tomato roots inoculated with P. aegyptiaca seeds in a PE bag system revealed that the parasite is killed only after its attachment to the tomato roots, at concentrations as low as 2.5 ppb. Imazapic sorption curves and calculated Kd and Koc values indicated that the herbicide Kd is similar in all soils excluding a two-fold higher coefficient in the Gadash farm soil, while the Koc was similar in all soils except the Eden farm soil, in which it was more than twofold lower. In greenhouse studies, control of P. aegyptiaca was achieved at >2.5 ppb imazapic, but adequate control requires repeated applications due to the 7-day half-life (t1/2) of the herbicide in the soil. Tracking of imazapic in soil and tomato roots revealed that the herbicide accumulates in the tomato host plant roots, but its movement to newly formed roots is limited. The data obtained in the laboratory and greenhouse studies provide invaluable knowledge for devising field imazapic application strategies via drip irrigation systems for efficient and selective broomrape control.

The Survial of Free Larvae of Heterodera shachtii in Soil

1937 ◽  
Vol 15 (2) ◽  
pp. 69-74 ◽  
Author(s):  
Mary T. Franklin
Keyword(s):  
Host Plant ◽  
Host Plants ◽  
Heterodera Schachtii

It is a well known fact that Heterodera schachtii in the brown cyst stage can survive in soil for several years in the absence of host plants. Fuchs found living contents in five-year old cysts of the beet strain of this nematode, while eight-year old cysts of the potato strain have been found by the writer still to be infective to the host plant. Thus, the starving out of this parasite by withholding susceptible crops would appear to be impracticable.

Effects of exogenous amino acid applications on the plant-parasitic nematode Heterodera schachtii

Nematology ◽  
2018 ◽  
Vol 20 (8) ◽  
pp. 713-727 ◽  
Author(s):  
Roman Christopher Blümel ◽  
Daniel F. Fischer ◽  
Florian M.W. Grundler
Keyword(s):  
Amino Acid ◽  
Host Plant ◽  
Parasitic Nematode ◽  
Plant Parasitic Nematode ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Direct Effects ◽  
Derivatives Of ◽  
Plant Parasitic

Summary Amino acid (AA) applications have been reported to affect plant-parasitic nematodes. Here, we analysed the effects of methionine (Met), lysine (Lys), threonine (Thr), isoleucine (Ile), homoserine (Hom) and tryptophan (Trp) on the sedentary plant-parasitic nematode, Heterodera schachtii, under in vitro conditions. No AA showed direct effects on the activity of infective second-stage juveniles (J2) of H. schachtii. Soaking J2 in Lys for 24 h increased the number of developing females and reduced the number of males. Thr treatments reduced the total number of nematodes developing in the host plant. The strongest effects were observed when AA were added to the nutrient medium in a monoxenic Arabidopsis thaliana culture. Ile, Met or Thr clearly reduced the number of female nematodes developing in the host plant. These AA are direct metabolic derivatives of Hom. Direct effects on pre-infective J2 can be differentiated from effects that may involve the host plant.

scholarly journals Hormonomic Changes Driving the Negative Impact of Broomrape on Plant Host Interactions with Arbuscular Mycorrhizal Fungi

2021 ◽  
Vol 22 (24) ◽  
pp. 13677
Author(s):  
Kiril Mishev ◽  
Petre I. Dobrev ◽  
Jozef Lacek ◽  
Roberta Filepová ◽  
Bistra Yuperlieva-Mateeva ◽  
...  
Keyword(s):  
Host Plant ◽  
Mycorrhizal Fungi ◽  
Negative Impact ◽  
Dominant Role ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Parasitic Plants ◽  
Plant Roots ◽  
Plant Host ◽  
Mycorrhizal Roots

Belowground interactions of plants with other organisms in the rhizosphere rely on extensive small-molecule communication. Chemical signals released from host plant roots ensure the development of beneficial arbuscular mycorrhizal (AM) fungi which in turn modulate host plant growth and stress tolerance. However, parasitic plants have adopted the capacity to sense the same signaling molecules and to trigger their own seed germination in the immediate vicinity of host roots. The contribution of AM fungi and parasitic plants to the regulation of phytohormone levels in host plant roots and root exudates remains largely obscure. Here, we studied the hormonome in the model system comprising tobacco as a host plant, Phelipanche spp. as a holoparasitic plant, and the AM fungus Rhizophagus irregularis. Co-cultivation of tobacco with broomrape and AM fungi alone or in combination led to characteristic changes in the levels of endogenous and exuded abscisic acid, indole-3-acetic acid, cytokinins, salicylic acid, and orobanchol-type strigolactones. The hormonal content in exudates of broomrape-infested mycorrhizal roots resembled that in exudates of infested non-mycorrhizal roots and differed from that observed in exudates of non-infested mycorrhizal roots. Moreover, we observed a significant reduction in AM colonization of infested tobacco plants, pointing to a dominant role of the holoparasite within the tripartite system.

Sign in / Sign up

Export Citation Format

Share Document