RESPONSE OF SELECTED TREE SEEDLINGS TO ROOT-KNOT NEMATODE (Meloidogyne incognita)

2021 ◽  
Vol 5 (1) ◽  
pp. 151-156
Author(s):  
Adebowale Adegboyega Tanimola ◽  
E. A. Ezeunara

Root-knot nematodes have been implicated in poor growth and death of trees in the nursery and newly established forest plantations. Cultivating resistant tree species is one of the viable methods in the management of nematode pests once they are identified. A pot experiment laid out in completely randomized design was conducted to screen fifteen selected tree seedlings for resistance to Meloidogyne incognita. Each tree seedling was replicated eight times and was grown on a steam-sterilized soil. The seedlings were inoculated each with 7,000 eggs of Meloidogyne incognita at four weeks after planting. Data were collected on plant height and stem girth at 12 weeks after inoculation. At termination, data were also collected on gall index (GI), final nematode population (Pf) and reproductive factor (RF). Data were analyzed using analysis of variance. Resistance or susceptibility status was assigned with Canto-Saenz host designation scheme. There was variability in the growth of the tree seedlings. Simphonia africana had the highest GI, Pf and RF of 3.3, 54,500 and 22.07, respectively and these values were significantly higher than values from other seedlings. Six tree seedlings;  Simphonia africana, Theobroma cacao, Gmelina arborea, Piptadeniastrum africana, Chrysophyluum albidium and Parkia biglobosa were found to be susceptible to M. incognita, while six (Tetrapleura  tetraptera, Anacardium occidentale, Annonas muricata, Dinium  guinensis and Vitex doniana) were found to be resistant and three (Treculia africana, Mangifera indica  and  Dacryodes edulis) were tolerant. Resistant tree seedlings should be planted in M. incognita-infested plantation and susceptible species should be treated even in

Agriscientia ◽  
2021 ◽  
Vol 38 (1) ◽  
pp. 93-98
Author(s):  
Ricardo Andreé Vega-Callo ◽  
Juan José Tamo-Zegarra ◽  
Cristiano Belle

This study aimed to evaluate the reaction of six grapevine rootstocks (MGT 101-14, Ritcher 110, Paulsen 1103, K 5BB, SO4, Salt creek) and two cultivars (Quebranta and Torontel) to three species of the root-knot nematode (Meloidogyne incognita, M. arenaria and M.hapla). The experiment was performed as a completely randomized design with an 8 × 3 factorial scheme and six replicates per treatment. The experimental unit in each replicate comprised a grapevine cutting planted in 3 kg bags with sterilized soil. Cuttings were inoculated with 5000 eggs + juveniles (J2) of M. incognita, M. arenaria and M. hapla. Six months after inoculation, plants were removed from the bags, and the reaction was determined by evaluating the number of galls (NG), number of nematodes per gram of root (NNGR), and reproduction factor (RF). The evaluated rootstocks, MGT 101-14, Ritcher 110, Paulsen 1103, K 5BB, SO4 and Salt Creek, were resistant to M. incognita, M. arenaria and M. hapla, except for Salt creek, which was susceptible to the latter. The Quebranta and Torontel cultivars were susceptible to the  Meloidogyne species under study.


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

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 520e-520
Author(s):  
Juan E Manzano ◽  
Oswaldo Valor

Mango fruits `Criollo de Bocado' harvested at the mature-green stage were treated with a hydrothermic treatment of 55 °C for 3 min and stored for 20 days at temperatures of 10 ± 2, 15 ± 2 and 28 ± 2 °C. A randomized design 2 × 3 × 4 with three replications was used. Some chemical parameters were analyzed, such as total soluble solids content (% TSS), pH, tritatable acidity, and TSS/tritatable acidity ratio. TSS content increased with storage time at low temperature. The pH increased measurably with storage temperature, while tritatable acidity values results had inconsistent data.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 520d-520
Author(s):  
Oswaldo Valor ◽  
Juan E Manzano

Mango fruits `Criollo de Bocado' harvested at the mature-green stage were treated with a hydrothermic treatment of 55 °C for 3 min and stored for 20 days to temperatures of 10 ± 2, 15 ± 2, and 28 ± 2 °C. A randomized design 2 × 3 × 4 with three replications was used. Physical parameters such as color (L*, a*, b*), firmnness, and fresh weight loss were studied. Results reported that mango fruits stored at 10.2 and 15.2 °C showed the highest firmness values. Skin color changed very fast during the first storage days, while pulp color required more time to achieve mature ripe color. Fresh weight loss tended to increase with storage time and with high storage temperature. The lowest storage temperture retarded softening in mango fruits and firmnness reached the highest values.


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 ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document