scholarly journals Potential Nematicidial Activity of Silver Nanoparticles Against the Root-Knot Nematode (Meloidogyne Incognita)

Author(s):  
Gregory C Bernard
2018 ◽  
Vol 10 (2) ◽  
pp. 148 ◽  
Author(s):  
Ahmed Hammad Nour El-Deen ◽  
Bahig Ahmed El-Deeb

Root-knot nematode, Meloidogyne incognita is the most economically important plant parasitic nematode species that cause serious damage to most agricultural crops including tomato worldwide. Nematicides do not provide long-term suppression of root-knot nematodes, and environmental and human health concerns are resulting in increased restrictions on their use. A greenhouse experiment was conducted to evaluate the effect of silver nanoparticles (AgNPs) at concentrations of 0.25, 0.5 and 1 mM as a potential nematicide on M. incognita infecting tomato. AgNP was biologically and chemically synthesized by a reaction of silver nitrate with ginger (Zingiber officinale) rhizomes aqueous extract and sodium borohydride, respectively. Results indicated that application of AgNPs improved plant growth and reduced nematode infection in comparison to silver nitrate and control treatments. The highest increment of fresh weight as well as the lowest numbers of galls and egg-masses was obtained when tomato plants was treated with AgNP produced by ginger extract at 1 mM.


Fruits ◽  
2009 ◽  
Vol 64 (5) ◽  
pp. 295-303 ◽  
Author(s):  
Hang Ye ◽  
Wen-jun Wang ◽  
Guo-jie Liu ◽  
Li-xin Zhu ◽  
Ke-gong Jia

Plant Disease ◽  
2017 ◽  
Vol 101 (6) ◽  
pp. 948-956 ◽  
Author(s):  
Alois A. Bell ◽  
Robert C. Kemerait ◽  
Carlos S. Ortiz ◽  
Sandria Prom ◽  
Jose Quintana ◽  
...  

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.


Author(s):  
Anil Baniya ◽  
Soumi Joseph ◽  
Larry Duncan ◽  
William Crow ◽  
Tesfamariam Mengistu

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.


PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e61259 ◽  
Author(s):  
Alice Teillet ◽  
Katarzyna Dybal ◽  
Brian R. Kerry ◽  
Anthony J. Miller ◽  
Rosane H. C. Curtis ◽  
...  

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