scholarly journals Effect of Temperature on and Histopathology of the Interaction Between Meloidogyne incognita and Thielaviopsis basicola on Cotton

1999 ◽  
Vol 89 (8) ◽  
pp. 613-617 ◽  
Author(s):  
N. R. Walker ◽  
T. L. Kirkpatrick ◽  
C. S. Rothrock
Keyword(s):  
Meloidogyne Incognita ◽  
Vascular Tissue ◽  
Root Surface ◽  
Effect Of Temperature ◽  
Infested Soil ◽  
Thielaviopsis Basicola ◽  
Root Knot Nematode ◽  
Cortical Cells ◽  
Node Ratio ◽  
Cotton Seeds

Controlled environments were used to study the relationship between the root-knot nematode (Meloidogyne incognita) and Thielaviopsis basicola on cotton. Temperature treatments were continuous 20, 24, and 28°C or two cyclic linear regimes with ranges of 14 to 32 or 18 to 28°C over 24 h. Cotton seeds were planted in fumigated soil infested with T. basicola, M. incognita, or both. After 42 days, pathogen effects on plant growth and pathogen development were evaluated. Histology was conducted on roots collected 14, 28, and 42 days after planting in the continuous 24°C treatment. Reductions in plant height-to-node ratio and total fresh weight were observed for soils infested with both pathogens compared with the control or with soils infested with either pathogen, except for M. incognita-infested soil at 28°C. T. basicola reduced root galling and reproduction of the nematode at all temperatures. Vascular discoloration caused by T. basicola was greater in the presence of M. incognita compared with that by T. basicola alone. At 2 and 4 weeks, histological studies showed that plants grown in all T. basicola-infested soils contained chlamydospore chains on the root surface and in cortical cells. The fungus was not observed inside the vascular cylinder. Roots from 4-week-old plants from soils infested with T. basicola and M. incognita showed fungal sporulation in vascular tissue and localized necrosis of vascular tissue adjacent to the nematodes. At 6 weeks, plants grown in soil infested with T. basicola alone exhibited no remaining cortical tissue and no evidence of vascular colonization by the fungus. Six-week-old plants grown in T. basicola + M. incognita-infested soils exhibited extensive vascular necrosis and sporulation within vascular tissue. These studies suggest that coinfection expands the temperature ranges at which the pathogens are able to cause plant damage. Further, M. incognita greatly increases the access of T. basicola to vascular tissue.

scholarly journals Histopathology of the nematodes Radopholus similis, Pratylenchus coffeae, Rotylenchulus reniformis and Meloidogyne incognita in plantain (Musa acuminata x M. balbisiana, AAB).

1969 ◽  
Vol 90 (1-2) ◽  
pp. 83-97
Author(s):  
Domingo Oramas-Nival ◽  
Jessé Román
Keyword(s):  
Meloidogyne Incognita ◽  
Distal Portion ◽  
Cellular Level ◽  
Similar Reaction ◽  
Radopholus Similis ◽  
Rotylenchulus Reniformis ◽  
Root Knot Nematode ◽  
Cortical Cells ◽  
Feeding Site ◽  
Parenchymal Cells

Radopholus similis produced sunken lesions that modified the normal cylindrical anatomy of the plantain root under severe necrotic conditions. The lesions caused by R. similis were similar to those caused by Pratylenchs coffeae, except that the latter did not alter the turgid condition of the root. At cellular level, R. similis induced hypertrophy of the nucleus and nucleolus of the cortical cells; however, P. coffeae did not produce a similar reaction. Rotylenchulus reniformis concentrated the parasitic activity on the feeder roots, thus causing necrosis at the feeding site. The reniform nematode induced a syncytia made up mainly of fourteen to twenty longitudinal and circumferential cells of the pericycle.The cells, the nucleus and the nucleolus of the syncytia were hypertrophied. Two nucleoli were observed in some of the syncytial cells. The cytoplasm of the syncytia was granular, dense and had spheric inclusions. A solid and mustache-like structure that we called feeding filter was observed between the feeding cell and the pericycle. The root-knot nematode, Meloidogyne incognita, caused profuse root galls and cortical cracks in the roots and exposition of the internal tissue, mainly at the distal portion of the main roots. Meloidogyne incognita penetrated the endodermis and the pericycle and induced hypertrophy on five to seven of the vascular parenchymal cells with multiple hypertrophied nuclei.

STUDIES ON THE FUSARIA WHICH CAUSE WILT IN MELONS: I. THE OCCURRENCE AND DISTRIBUTION OF RACES OF THE MUSKMELON AND WATERMELON FUSARIA AND A HISTOLOGICAL STUDY OF THE COLONIZATION OF MUSKMELON PLANTS SUSCEPTIBLE OR RESISTANT TO FUSARIUM WILT

1958 ◽  
Vol 36 (3) ◽  
pp. 393-410 ◽  
Author(s):  
James Reid
Keyword(s):  
Host Plants ◽  
Histological Study ◽  
Effect Of Temperature ◽  
Infested Soil ◽  
Time Intervals ◽  
Cortical Cells ◽  
Susceptible Host ◽  
Host Parasite ◽  
Respective Host ◽  
Comparable Time

It has been shown that more than one type of isolate of both the muskmelon Fusarium and the watermelon Fusarium occur naturally in infested soil. The isolates of both organisms could be divided into many cultural races, depending on the number of isolations made. Among these cultural races differences were demonstrated in their ability to establish successful host–parasite relationships with their respective host plants. The field reactions of various host varieties were shown to be a function of the races present in the soil at a given time. Fluctuations in the relative frequency of the races present in a field have been shown to occur, as well as changes in the races present.The muskmelon wilt organism penetrated a susceptible host variety between cells in the region of elongation. The cortex was then colonized intercellularly, later intracellularly. The fungus then penetrated the stele, establishing itself in the vessels. Eventually hyphae were present throughout the vessels and later passed out to infect stelar and cortical tissues at various loci.The fungus also invaded the primary meristem intercellularly, later intracellularly, and established itself in young protoxylem vessels or developing cortical cells. Penetration also occurred through tears in the cortex caused by developing secondary roots.Colonization of a resistant host occurred in the same manner, but there was always less fungus in the resistant host than in the susceptible host after comparable time intervals. This difference could not be correlated with the morphology of the resistant host.The effect of temperature on colonization appeared to be on the aggressiveness of the parasite, rather than on the susceptibility of the host.

scholarly journals Isolation of a cDNA Encoding a β-1,4-endoglucanase in the Root-Knot Nematode Meloidogyne incognita and Expression Analysis During Plant Parasitism

1999 ◽  
Vol 12 (7) ◽  
pp. 585-591 ◽  
Author(s):  
Marie-Noëlle Rosso ◽  
Bruno Favery ◽  
Christine Piotte ◽  
Laury Arthaud ◽  
Jan M. De Boer ◽  
...  
Keyword(s):  
Meloidogyne Incognita ◽  
Catalytic Domain ◽  
Cellulase Activity ◽  
Root Surface ◽  
Binding Domain ◽  
Cellulose Binding Domain ◽  
Root Knot Nematode ◽  
Cyst Nematodes ◽  
Adult Females ◽  
Cellulose Binding

A β-1,4-endoglucanase encoding cDNA (EGases, E.C. 3.2.1.4), named Mi-eng-1, was cloned from Meloidogyne incognita second-stage juveniles (J2). The deduced amino acid sequence contains a catalytic domain and a cellulose-binding domain separated by a linker. In M. incognita, the gene is transcribed in the migratory J2, in males, and in the sedentary adult females. In pre-parasitic J2, endoglucanase transcripts are located in the cytoplasm of the subventral esophageal glands. The presence of β-1,4-endoglucanase transcripts in adult females could be related to the expression of the gene in esophageal glands at this stage. However, cellulase activity within the egg matrix of adult females suggests that the endoglucanase may also be synthesized in the rectal glands and involved in the extrusion of the eggs onto the root surface. The maximum identity of the predicted MI-ENG-1 catalytic domain with the recently cloned cyst nematode β-1,4-endoglucanases is 52.5%. In contrast to cyst nematodes, M. incognita pre-parasitic J2 were not found to express a β-1,4-endoglucanase devoid of a cellulose-binding domain.

scholarly journals Control of Root-Knot Nematode (Meloidogyne incognita) in Tomato (Solanum lycopersicum) Crop Using Siam Weed (Chromolaena odorata) Compost Manure

2020 ◽  
Vol 28 (1) ◽  
pp. 87-92
Author(s):  
Stephen A. Abolusoro ◽  
Aruna Olasekan Adekiya ◽  
Charity Aremu ◽  
Sunday Ige ◽  
Nkechi B. Izuogu ◽  
...  
Keyword(s):  
Field Experiment ◽  
Meloidogyne Incognita ◽  
Soil Amendment ◽  
Growth And Yield ◽  
Infested Soil ◽  
Chromolaena Odorata ◽  
Root Knot Nematode ◽  
Tomato Seedlings ◽  
Environmentally Safe ◽  
Compost Manure

AbstractA field experiment was conducted at Landmark University Omu-Aran, Nigeria from June to November 2017 and repeated at the same time in the year 2018 on a nematode infested soil to evaluate the effects of different amounts of Siam weed compost on the performance of root-knot nematode (RKN) infested tomato. The compost was applied a week before planting as soil amendment at the amount of 0.0, 0.5, 1.5, and 2.0 t·ha−1, while carbofuran was applied at the rate of 3.0 kg·ha−1. Four weeks old tomato seedlings cultivar ‘Roma VF’, which is susceptible to RKN, was transplanted to already prepared soil. Results of the experiment showed that the compost, especially in the amount 2 t·ha−1 and carbofuran at 3 kg·ha−1, brought about significant reduction of the population of RKN in soil and roots, and a significant increase in the growth and yield of tomato. The result of the experiment showed that Siam compost can be used for the managing root-knot nematodes in tomato cultivation, as an environmentally safe factor.

scholarly journals Effects of Meloidogyne incognita and Thielaviopsis basicola on Cotton Growth and Root Morphology

2014 ◽  
Vol 104 (5) ◽  
pp. 507-512 ◽  
Author(s):  
Jianbing Ma ◽  
Juan Jaraba ◽  
Terrence L. Kirkpatrick ◽  
Craig S. Rothrock
Keyword(s):  
Meloidogyne Incognita ◽  
Root Morphology ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Thielaviopsis Basicola ◽  
Root Knot Nematode ◽  
Root Parameters ◽  
Topological Parameters ◽  
Top Dry Weight ◽  
Additional Approach

Effects of the root-knot nematode Meloidogyne incognita and the fungal pathogen Thielaviopsis basicola on cotton seedling growth and root morphology were evaluated in controlled environmental experiments. Four pathogen treatments, including noninfested soil, soil infested with M. incognita, soil infested with T. basicola, and soil infested with both pathogens were evaluated at soil bulk densities (BDs) of 1.25 and 1.50 g/cm3. Plant growth and the morphology of the root systems were evaluated 44 days after planting. Infestation with M. incognita and T. basicola together significantly reduced seedling emergence, number of stem nodes, and root system volume compared with either pathogen alone. Either M. incognita or T. basicola reduced plant height, root fresh weight, top dry weight; root parameters total root length, surface area, and links; and root topological parameters magnitude, altitude, and exterior path length. M. incognita infection increased root radius. Root colonization by T. basicola increased with the presence of M. incognita at the lower soil BD. In contrast to previous research with Pythium spp., root topological indices (TIs) were similar with all of the treatments. Root TIs were near 1.92, indicating a herringbone (less branching) root architectural structure. Studying root architecture using a topological model offers an additional approach to evaluating fungi and nematodes and their interactions for soilborne-pathogen systems.

Resistance mechanisms ofPrunusrootstocks to root-knot nematode,Meloidogyne incognita

Fruits ◽  
2009 ◽  
Vol 64 (5) ◽  
pp. 295-303 ◽  
Author(s):  
Hang Ye ◽  
Wen-jun Wang ◽  
Guo-jie Liu ◽  
Li-xin Zhu ◽  
Ke-gong Jia
Keyword(s):  
Meloidogyne Incognita ◽  
Resistance Mechanisms ◽  
Root Knot Nematode

scholarly journals Genetic Diversity, Virulence, and Meloidogyne incognita Interactions of Fusarium oxysporum Isolates Causing Cotton Wilt in Georgia

Plant Disease ◽  
2017 ◽  
Vol 101 (6) ◽  
pp. 948-956 ◽  
Author(s):  
Alois A. Bell ◽  
Robert C. Kemerait ◽  
Carlos S. Ortiz ◽  
Sandria Prom ◽  
Jose Quintana ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Fusarium Oxysporum ◽  
Meloidogyne Incognita ◽  
Root Knot Nematode ◽  
Soil Infestation ◽  
Causal Pathogen ◽  
Complementation Groups ◽  
Shoot Weight ◽  
Cotton Wilt ◽  
Significant Disease

Locally severe outbreaks of Fusarium wilt of cotton (Gossypium spp.) in South Georgia raised concerns about the genotypes of the causal pathogen, Fusarium oxysporum f. sp. vasinfectum. Vegetative complementation tests and DNA sequence analysis were used to determine genetic diversity among 492 F. oxysporum f. sp. vasinfectum isolates obtained from 107 wilted plants collected from seven fields in five counties. Eight vegetative complementation groups (VCG) were found, with VCG 01117B and VCG 01121 occurring in 66% of the infected plants. The newly recognized VCG 01121 was the major VCG in Berrien County, the center of the outbreaks. All eight VCG resulted in significant increases in the percentages of wilted leaves (27 to 53%) and significant reductions in leaf weight (40 to 67%) and shoot weight (33 to 60%) after being stem punctured into Gossypium hirsutum ‘Rowden’. They caused little or no significant reductions in shoot weight and height or increases in foliar symptoms and vascular browning in a soil-infestation assay. Soil infestation with Meloidogyne incognita race 3 (root-knot nematode) alone also failed to cause significant disease. When coinoculated with M. incognita race 3, all VCG caused moderate to severe wilt. Therefore, the VCG identified in this study belong to the vascular-competent pathotype, and should pose similar threats to cotton cultivars in the presence of the root-knot nematode. Use of nematode-resistant cultivars, therefore, is probably the best approach to control the disease in Georgia.

scholarly journals The role of Caenorhabditis elegans sex-determination homologs, Mi-sdc-1 and Mi-tra-1 in Meloidogyne incognita

2021 ◽  
Author(s):  
Anil Baniya ◽  
Soumi Joseph ◽  
Larry Duncan ◽  
William Crow ◽  
Tesfamariam Mengistu
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
Meloidogyne Incognita ◽  
Egg Production ◽  
Target Genes ◽  
Parasitic Nematode ◽  
Plant Parasitic Nematode ◽  
Root Knot Nematode ◽  
Model Free ◽  
Plant Parasitic

AbstractSex determination is a key developmental event in all organisms. The pathway that regulates sexual fate has been well characterized at the molecular level in the model free-living nematode Caenorhabditis elegans. This study aims to gain a preliminary understanding of sex-determining pathways in a plant-parasitic nematode Meloidogyne incognita, and the extent to which the roles of the sex determination genes are conserved in a hermaphrodite species, C. elegans, and plant-parasitic nematode species, M. incognita. In this study, we targeted two sex-determining orthologues, sdc-1 and tra-1 from M. incognita using RNA interference (RNAi). RNAi was performed by soaking second-stage juveniles of M. incognita in a solution containing dsRNA of either Mi-tra-1or Mi-sdc-1 or both. To determine the effect of RNAi of the target genes, the juveniles treated with the dsRNA were inoculated onto a susceptible cultivar of cowpea grown in a nutrient pouch at 28 °C for 5 weeks. The development of the nematodes was analyzed at different time points during the growth period and compared to untreated controls. Our results showed that neither Mi-sdc-1 nor Mi-tra-1 have a significant role in regulating sexual fate in M. incognita. However, the silencing of Mi-sdc-1 significantly delayed maturity to adult females but did not affect egg production in mature females. In contrast, the downregulation of Mi-tra-1 transcript resulted in a significant reduction in egg production in both single and combinatorial RNAi-treated nematodes. Our results indicate that M. incognita may have adopted a divergent function for Mi-sdc-1 and Mi-tra-1distinct from Caenorhabditis spp. However, Mi-tra-1 might have an essential role in female fecundity in M. incognita and is a promising dsRNA target for root-knot nematode (RKN) management using host-delivered RNAi.

Sign in / Sign up

Export Citation Format

Share Document