scholarly journals Evaluating resistant brassica trap crops to manage Heterodera schachtii (Schmidt) infestations in eastern England

2018 ◽  
Vol 75 (2) ◽  
pp. 438-443 ◽  
Author(s):  
Alistair JD Wright ◽  
Matthew A Back ◽  
Mark Stevens ◽  
Debbie L Sparkes
Nematology ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 813-825
Author(s):  
Alistair J.D. Wright ◽  
Debbie L. Sparkes ◽  
Mark Stevens ◽  
Matthew A. Back

Summary The hatching and emergence of juveniles from cysts of Heterodera schachtii in response to various stimuli are well understood. These responses relate to means of optimising the chances of successful reproduction and survival of populations. However, the effect of different cultivars of host species is not so well understood. To gain a further understanding of any differences between cultivars of host species, we conducted a number of experiments using root leachates obtained from a range of cultivars of sugar beet (Beta vulgaris), radish (Raphanus sativus) and white mustard (Sinapis alba). Heterodera schachtii cysts were exposed to root leachate solutions in in vitro laboratory assays during which emergence of second-stage juveniles (J2) from cysts was monitored weekly. Significant differences in the stimulation of hatch of J2 were found in response to different sugar beet cultivars and these differences may be driven by differing growth habits of such varieties. However, results obtained from experiments using brassica varieties showed contrasting responses. In one experiment, root leachates appeared to inhibit hatch of J2. However, two experiments did show a stimulation of hatch of J2 and also significant differences in hatch responses due to the age of the plant. These findings may help develop future screening procedures for brassica trap crops and help identify those that show the greatest potential for H. schachtii control.


1999 ◽  
Vol 89 (1) ◽  
pp. 68-73 ◽  
Author(s):  
M. Kaplan ◽  
E. P. Caswell-Chen ◽  
V. M. Williamson

The hypothesis that host plants exert selection pressure on Heterodera schachtii populations was tested. Host selection of genotypes from three genetically distinct isolates of H. schachtii was assessed using cabbage, sugar beet, oilseed radish (Raphanus sativus), and white mustard (Sinapis alba). The plants represent a range of susceptibility to H. schachtii and included R. sativus and S. alba, because cultivars of those species have been used as trap crops for H. schachtii in Europe. Genotypic differences in amplified fragment length polymorphism (AFLP) and random amplified polymorphic DNA (RAPD) markers were detected among the isolates after they reproduced on the different hosts. The poorest host plant, R. sativus, resulted in the greatest number of changes in both AFLP and RAPD markers. Oilseed radish selected nematode genotypes in less than four nematode generations. The nematode population genotypes detected by RAPD analyses after selection on oilseed radish were observed even after nematode populations were transferred back to the other three hosts. The genetic markers that were detected after selection were influenced by the genotypes of the original nematode isolates. The results indicate the utility of RAPDs and AFLPs for identifying and monitoring intraspecific genetic variability in nematodes and for understanding nematode population responses to host plants. Nematode management practices such as using resistant cultivars may alter gene frequencies, thereby reducing the efficacy of the tactic and exacerbating the nematode's potential to damage subsequent crops.


2015 ◽  
Vol 2 (1) ◽  
pp. 12-22 ◽  
Author(s):  
L. Pylypenko ◽  
K. Kalatur

Heterodera schachtii Schmidt, 1871 is one of the most economically important pests of sugar beet (Beta vulgaris L.) worldwide. It is also widespread in most sugar beet growing regions in Ukraine causing serious yield reduction and decreasing sugar content of sugar beet in infested fi elds. An advanced parasitic strategy of H. schachtii is employed to support nematode growth, reproduction and harmfulness. In intensive agriculture systems the nematode control measures heavily rely on nematicides and good agricultural practice (crop rota- tion in the fi rst place). But alternative strategies based on nematode resistant sugar beet cultivars and hybrids are required as none of nematicides approved for the open fi eld application are registered in Ukraine. Here we review the achievements and problems of breeding process for H. schachtii resistance and provide the results of national traditional breeding program. Since the beginning of 1980s fi ve sugar beet cultivars (Verchnyatskyi 103, Yaltuschkivska 30, Bilotcerkivska 45, BTs-40 and Yuvileynyi) and seventeen lines partly resistant or toler- ant to H. schachtii have been obtained throughout targeted crossing and progenies assessment in the infested fi elds. The further directions for better utilization of genetic sources for nematode resistance presented in na- tional gene bank collection are emphasized. There is a need for more accurate identifi cation of resistance genes, broader application of reliable molecular markers (suitable for marker-assisted selection of nematode resistant plants in the breeding process) and methods for genetic transformation of plants. Crop cash value and national production capacity should drive the cooperation in this fi eld. Knowledge as well as germplasm exchange are thereby welcomed that can benefi t breeding progress at national and international level.


1977 ◽  
Vol 9 (1) ◽  
pp. 129-135 ◽  
Author(s):  
C. Robert Taylor ◽  
Ronald D. Lacewell

Throughout the southern states and at the federal level, much attention is being focused on the appropriate strategy for controlling cotton insect pests, particularly the boll weevil. This paper presents estimated economic impacts to farmers, regions and consumers of implementing three alternative boll weevil control strategies. One strategy evaluated is a proposed boll weevil eradication program which involves integrating many controls including insecticides, reproduction-diapause control by early season stalk destruction, pheromone-baited traps, trap crops, early season control with insecticide, and massive releases of sterile boll weevils. The plan is to eradicate the boll weevil in the U.S., and then indefinitely maintain a barrier at the U.S.-Mexico border to prevent future weevil immigration to the U.S.


2021 ◽  
Vol 22 (12) ◽  
pp. 6450
Author(s):  
Anita Wiśniewska ◽  
Kamila Wojszko ◽  
Elżbieta Różańska ◽  
Klaudia Lenarczyk ◽  
Karol Kuczerski ◽  
...  

Transcription factors are proteins that directly bind to regulatory sequences of genes to modulate and adjust plants’ responses to different stimuli including biotic and abiotic stresses. Sedentary plant parasitic nematodes, such as beet cyst nematode, Heterodera schachtii, have developed molecular tools to reprogram plant cell metabolism via the sophisticated manipulation of genes expression, to allow root invasion and the induction of a sequence of structural and physiological changes in plant tissues, leading to the formation of permanent feeding sites composed of modified plant cells (commonly called a syncytium). Here, we report on the AtMYB59 gene encoding putative MYB transcription factor that is downregulated in syncytia, as confirmed by RT-PCR and a promoter pMyb59::GUS activity assays. The constitutive overexpression of AtMYB59 led to the reduction in A. thaliana susceptibility, as indicated by decreased numbers of developed females, and to the disturbed development of nematode-induced syncytia. In contrast, mutant lines with a silenced expression of AtMYB59 were more susceptible to this parasite. The involvement of ABA in the modulation of AtMYB59 gene transcription appears feasible by several ABA-responsive cis regulatory elements, which were identified in silico in the gene promoter sequence, and experimental assays showed the induction of AtMYB59 transcription after ABA treatment. Based on these results, we suggest that AtMYB59 plays an important role in the successful parasitism of H. schachtii on A. thaliana roots.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Olaf Kranse ◽  
Helen Beasley ◽  
Sally Adams ◽  
Andre Pires-daSilva ◽  
Christopher Bell ◽  
...  

Abstract Plant-parasitic nematodes are a continuing threat to food security, causing an estimated 100 billion USD in crop losses each year. The most problematic are the obligate sedentary endoparasites (primarily root knot nematodes and cyst nematodes). Progress in understanding their biology is held back by a lack of tools for functional genetics: forward genetics is largely restricted to studies of natural variation in populations and reverse genetics is entirely reliant on RNA interference. There is an expectation that the development of functional genetic tools would accelerate the progress of research on plant-parasitic nematodes, and hence the development of novel control solutions. Here, we develop some of the foundational biology required to deliver a functional genetic tool kit in plant-parasitic nematodes. We characterize the gonads of male Heterodera schachtii and Meloidogyne hapla in the context of spermatogenesis. We test and optimize various methods for the delivery, expression, and/or detection of exogenous nucleic acids in plant-parasitic nematodes. We demonstrate that delivery of macromolecules to cyst and root knot nematode male germlines is difficult, but possible. Similarly, we demonstrate the delivery of oligonucleotides to root knot nematode gametes. Finally, we develop a transient expression system in plant-parasitic nematodes by demonstrating the delivery and expression of exogenous mRNA encoding various reporter genes throughout the body of H. schachtii juveniles using lipofectamine-based transfection. We anticipate these developments to be independently useful, will expedite the development of genetic modification tools for plant-parasitic nematodes, and ultimately catalyze research on a group of nematodes that threaten global food security.


Nematology ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 165-177 ◽  
Author(s):  
Rasha Haj Nuaima ◽  
Johannes Roeb ◽  
Johannes Hallmann ◽  
Matthias Daub ◽  
Holger Heuer

Summary Characterising the non-neutral genetic variation within and among populations of plant-parasitic nematodes is essential to determine factors shaping the population genetic structure. This study describes the genetic variation of the parasitism gene vap1 within and among geographic populations of the beet cyst nematode Heterodera schachtii. Forty populations of H. schachtii were sampled at four spatial scales: 695 km, 49 km, 3.1 km and 0.24 km. DGGE fingerprinting showed significant differences in vap1 patterns among populations. High similarity of vap1 patterns appeared between geographically close populations, and occasionally among distant populations. Analysis of spatially sampled populations within fields revealed an effect of tillage direction on the vap1 similarity for two of four studied fields. Overall, geographic distance and similarity of vap1 patterns of H. schachtii populations were negatively correlated. In conclusion, the population genetic structure was shaped by the interplay between the genetic adaptation and the passive transport of this nematode.


Nematology ◽  
2007 ◽  
Vol 9 (4) ◽  
pp. 451-458 ◽  
Author(s):  
Julia Hofmann ◽  
Florian Grundler

AbstractSedentary cyst and root-knot nematodes withdraw large amounts of solutes from feeding structures induced in host roots. The feeding structures are specialised cells with a high metabolic activity and a tremendous capacity in translocation of nutrients. The required nutrients are provided by the plant transport systems – water and inorganic solutes from the xylem, assimilates such as sugars and amino acids from the phloem. Here we discuss the available data on the mechanisms by which nutrients are translocated into the nematode feeding sites. The interaction between Heterodera schachtii and Arabidopsis thaliana serves as a model system for cyst nematodes. In this case sufficient data are available to propose a conclusive concept for the mechanisms of nutrient flow: basically, in the early stages of nematode development syncytia are symplasmically isolated, so that transport proteins are responsible for the nutrient supply. Later, connections to the phloem via plasmodesmata are established, so that developing females are well supplied with assimilates. The interactions of root-knot nematodes with their hosts share a number of similarities but the data currently available are not sufficient to draw similar conclusions. As nutrient supply and functionality of feeding structures are the basis of biotrophic parasitism of sedentary nematodes, it is tempting to unravel the mechanisms by which both plant and nematodes influence each other via nutrient fluxes.


1996 ◽  
Vol 112 (4) ◽  
pp. 1421-1427 ◽  
Author(s):  
A. Bockenhoff ◽  
DAM. Prior ◽  
FMW. Grundler ◽  
K. J. Oparka

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