The isolation of a single spore isolate of Pasteuria penetrans and its pathogenicity on Meloidogyne javanica

Nematology ◽  
2004 ◽  
Vol 6 (4) ◽  
pp. 463-471 ◽  
Author(s):  
James R. Trotter ◽  
Daim Ali Darban ◽  
Simon R. Gowen ◽  
Alistair H. Bishop ◽  
Barbara Pembroke
Keyword(s):  
Dna Sequences ◽  
Meloidogyne Javanica ◽  
Egg Mass ◽  
Parental Population ◽  
Pasteuria Penetrans ◽  
Root Knot Nematode ◽  
Single Spore ◽  
Mass Line ◽  
Single Spore Isolate ◽  
Spore Population

Abstract We have obtained a single spore isolate of Pasteuria penetrans, derived by allowing a single spore to attach to a secondstage juvenile (J2) of the root-knot nematode Meloidogyne javanica. By analysing DNA sequences at three different loci we have obtained evidence that the isolate is, indeed, genetically pure. We compared the ability of the single spore isolate and the parent population from which it was selected to attach to and parasitise both the original population of M. javanica on which it was isolated and a single egg mass line derived from it. There was no difference in the attachment of spores of the single spore isolate to juveniles compared to the parental population, although there were higher numbers of both attaching to J2 of the single egg mass line compared to its parental population. Judging from the numbers of egg masses and Pasteuria -infected females, the single spore isolate was less pathogenic to the parental population of M. javanica than was the parental spore population.

scholarly journals Reaction of wild Solanaceae rootstocks to the parasitism of (Meloidogyne javanica)

2019 ◽  
Vol 37 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Jéssica Cardoso ◽  
Luiza Tonelli ◽  
Talita S Kutz ◽  
Fernanda D Brandelero ◽  
Thiago de O Vargas ◽  
...  
Keyword(s):  
Wild Species ◽  
Meloidogyne Javanica ◽  
Control Treatment ◽  
Egg Mass ◽  
Santa Cruz ◽  
Root Knot Nematode ◽  
Final Population ◽  
Solanum Viarum ◽  
Susceptible Tomato ◽  
Reproduction Factor

ABSTRACT Intensive production of vegetables in greenhouses can increase the amount of inoculum of soil-borne pathogens, such as the root-knot nematode. Thus, in this study we aimed to evaluate the potential of Solanaceae as rootstocks resistant to Meloidogyne javanica nematodes as an alternative to tomato grafting. The experiment consisted of seven treatments: wild species joá-vermelho (Solanum capsicoides), joá-bagudo (Solanum palinacanthum), joá-bravo (Solanum viarum), jurubeba (Solanum spp.) and the commercial tomato cultivars Santa Cruz Kada, Batalha and Guardião. The analyzed variables were gall index; egg mass index; final nematode population; reproduction factor (FR) and reaction: susceptibility, resistance and immunity; fresh shoot and root mass and number of eggs per gram of roots. The wild species joá-vermelho, joá-bagudo and jurubeba showed resistance, with the lowest indexes of galls, egg mass, final population of nematodes and number of eggs per gram of root, not differing from the resistant control treatment (hybrid rootstock Guardião), with a reproduction factor less than 1, showing potential to be used as a resistant rootstock to M. javanica. Joá-bravo species showed susceptibility to the root-knot nematode, with a FR>1, not differing from the susceptible tomato Santa Cruz Kada. These results confirm the resistance of wild species to nematode parasitism, which can prove the viability of use as possible alternative rootstocks, and reinforce the idea that more studies should be carried out aiming to provide more viable options for farmers and plantlet producers.

scholarly journals Determining of root-knot nematode (Meloidogyne javanica) damage function for tomato cultivars

2013 ◽  
Vol 58 (2) ◽  
pp. 147-157 ◽  
Author(s):  
Fatemeh Gharabadiyan ◽  
Salar Jamali ◽  
Reza Komeili
Keyword(s):  
Maximum Yield ◽  
Meloidogyne Javanica ◽  
Yield Reduction ◽  
Egg Mass ◽  
Initial Population ◽  
Root Knot Nematode ◽  
Effective Population ◽  
Damage Functions ◽  
Resistance Level ◽  
Tomato Cultivars

Root-knot nematode (Meloidogyne javanica) management should be partly based on the knowledge of the threshold density, and this value is likely to vary depending on the resistance level of the tomato cultivars. The damage functions based on four initial population densities (Pi) (0, 1,000, 3,000 and 5,000 egg kg-1 of soil) of root-knot nematode were determined in four tomato cultivars. The experiment was performed in completely randomized design with four replications. The results showed that yield responses to Pi were fitted properly by a log-logistic function with three parameters. The most susceptible cultivar was ?Rutgers? based on EP50 and EP10 (effective population of nematodes, reducing 50% or 10% of maximum yield or shoot fresh weight respectively) and three others were relatively resistant. EP10 is more applicable than EP50 because 50% yield reduction is unacceptable in most situations. EP10 for yield of ?Rutgers?, ?Efialto?, ?Falat 111?, ?Gina VF? was 500, 3,021, 2,998, and 3,000 egg kg-1 of soil, respectively. The correlation coefficients among gall index, egg mass and reproductive factors were positively related. Reproduction factor and root gall indices were greater in ?Rutgers? than in the other cultivars (P?0.05). For ?Gina VF? as a relatively resistant cultivar it seemed that increasing of Pi up to 5,000 or more egg kg-1 soil might break its resistance.

scholarly journals Survey and Identification of Root-Knot Nematodes Associated with Brinjal Crops in Fatehabad, Agra

2016 ◽  
Vol 4 (1) ◽  
pp. 114-119
Author(s):  
Bindhya Yadav ◽  
Sanoj Kumar
Keyword(s):  
Meloidogyne Javanica ◽  
Mixed Population ◽  
Egg Mass ◽  
Root Knot Nematode ◽  
Index Point ◽  
Root Knot Nematodes ◽  
Heavy Infection ◽  
Disease Occurrence ◽  
Gall Index ◽  
Almost All

A survey was conducted over a period of one and half year to estimate the occurrence of root-knot nematode disease on brinjal crops in five selected localities in and around Fatehabad, Agra. Our survey indicates that brinjal crops grown in the selected localities were heavily infested with root-knot nematodes. Highest frequency of disease occurrence in which almost all the roots have knot-like appearance (>85%) was reported from Firozabad Road area. Other localities were also having the significant infestations and these were reported as 80%, 78%, 65%,62% respectively. To access the damage caused by root-knot nematodes in brinjal crop, Meloidogyne gall index and its egg-mass index were calculated and these were found in the range of 2-5. An increased gall index and egg-mass index point to heavy infection on selected crops. Sampled crop showed the significant presence of Meloidogyne javanica. However, there were other species of root-knot nematode as mixed population was also reported. Other species of the root-knot nematodes which were reported in this survey was M. incognita. This survey indicates that the M. javanica is a frequently occurring population in brinjal field infested with root-knot disease.

Characterisation of mjap genes encoding novel secreted proteins from the root-knot nematode, Meloidogyne javanica

Nematology ◽  
2009 ◽  
Vol 11 (2) ◽  
pp. 253-265 ◽  
Author(s):  
Emmanuel Tzortzakakis ◽  
Vivian Blok ◽  
Mohamed Adam ◽  
Mark Phillips
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Developmental Stages ◽  
Meloidogyne Javanica ◽  
Egg Mass ◽  
Root Knot Nematode ◽  
Amino Acid Repeat ◽  
Transcription Analysis ◽  
C Terminus ◽  
Genes Encoding

AbstractTwo homologues of map-1, which encodes a putative avirulence factor, were found in a single egg mass line of the root-knot nematode Meloidogyne javanica that was virulent to the Mi-resistant gene. The main difference between the two encoded proteins of these homologues, MJ-MAP-1 and MJ-MAP-2, was the position of a 13 amino acid repeat region. Genes encoding two related but novel proteins, MJAP-1 and MJAP-2 (290 and 283 amino acids, respectively, including a potential signal secretion peptide), were also isolated from M. javanica. They have high similarity to MAP at the C-terminus. MJAP-1 and MJAP-2 differ from each other in the number and position of a seven-amino-acid repeat and in five other amino acids. The mjap genes are expressed in the subventral pharyngeal glands of second-stage juveniles of M. javanica, and transcription analysis in different developmental stages showed expression in the juvenile stage but not in eggs or adult females. Both mjap-1 and mjap-2 were expressed in both Mi-virulent and avirulent lines of M. javanica.

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