scholarly journals Susceptibility of six corn varieties (Zea maysL.) to Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
L.P. Astuti ◽  
S.M. Yahya ◽  
M.S. Hadi
Keyword(s):  
Free Choice ◽  
Resistance Mechanism ◽  
Sitophilus Zeamais ◽  
Test Method ◽  
Choice Test ◽  
Resistance Level ◽  
Agricultural Produce ◽  
Antibiosis Resistance ◽  
Moderately Resistant ◽  
Agricultural Loss

Agricultural produce is commonly stored in warehouses after the harvest period, before being utilized and fulfilling the crop stock. However, crop threats are not only present during cultivation and harvest, but crops can also be infected during storage, which leads to agricultural loss. This research aimed to observe the resistance level of corn varieties of Bisma, Bisi 18, Bisi 19, Pioneer 21, Pioneer 29, and Pertiwi 3 to the Sitophilus zeamaispest of stored product insects. This resistance was based on the mechanism of non-preference (antixenosis) resistance, measured with the Free Choice Test Method (FCTM), and antibiosis resistance mechanism, measured with the No Choice Test Method (NCTM). The results showed that based on the susceptibility index (Dobie, 1974), corn varieties of Pertiwi 3 were categorized as resistant to S. zeamais pests, while the varieties of Bisi 19, Bisma, Bisi 18, Pioneer 21 and Pioneer 29 were moderately resistant.

scholarly journals Study of Host Preference and the Comparison of some Biological Characteristcs of Bemisia Tabasi (Genn) on Tomato Varieties

2013 ◽  
Vol 53 (2) ◽  
pp. 137-142
Author(s):  
Masoomeh Samareh Fekri ◽  
Mohammad Amin Samih ◽  
Sohrab Imani ◽  
Mehdi Zarabi
Keyword(s):  
Free Choice ◽  
Host Preference ◽  
Resistance Mechanism ◽  
Total Mortality ◽  
Statistical Design ◽  
The Other ◽  
Choice Test ◽  
Percentage Mortality ◽  
Tomato Variety ◽  
Choice Preference

Abstract The resistance of 8 tomato varieties to cotton white fly, Bemisia tabaci (Genn) (Hemiptera: Aleyrodidae), was evaluated in four greenhouse experiments. In the first experiment, we evaluated the attractiveness and preference for oviposition in a free-choice test (randomized blocks, 8 treatments, and 5 replications). In the other experiments, we evaluated the no-choice preference for oviposition (randomized blocks, 4 treatments, and 4 replications). The whitefly egg-adult cycle was monitored using a statistical design in randomized blocks with four replications. The percentage mortality of immature stages was also determined (randomized blocks with four replications). In the free-choice test, the tomato variety Rio Grande was the most attractive to adults, while the variety Cheffalat had the lowest number of adults. Also in this assay, the variety CAL-JN3 presented the lowest number of eggs, while the variety Ergon presented the highest number of eggs. In the no-choice test, the varieties Chef-falat and CAL-JN3 remained resistant. Consequently, for these two varieties non-preference is the oviposition resistance mechanism. The egg-adult cycle varied from 26.02 days (Ergon) to 26.66 days (CAL-JN3). The total mortality varied from 20.52 (Ergon) to 33.97 (CAL-JN3). Considering all the characteristics, the variety CAL-JN3 was the most resistant to B. tabaci among all the tomato varieties studied, while variety Ergon was susceptible.

scholarly journals Assessment of Soybean Resistance Level to Pod Sucking Bug Riptortus linearis F. (Hemiptera: Coreidae) based on No-choice and Free-choice Tests

2022 ◽  
Author(s):  
A. Krisnawati ◽  
K. Noerwijati ◽  
S.W. Indiati ◽  
Trustinah . ◽  
E. Yusnawan ◽  
...  
Keyword(s):  
Free Choice ◽  
Block Design ◽  
Limiting Factors ◽  
Choice Test ◽  
Average Intensity ◽  
Resistance Level ◽  
Seed Damage ◽  
Randomized Block Design ◽  
Choice Tests ◽  
Soybean Genotypes

Background: The infestation of the pod sucking bug Riptortus linearis is one of the limiting factors of soybean productivity in Indonesia. The research aims were to identify the level of resistance to the pod sucking bug R. linearis on several soybean genotypes based on the no-choice test (NCT) and free-choice tests (FCT). Methods: The genetic materials used were 49 soybean genotypes. The study was conducted in the Indonesian Legumes and Tuber Crops Research Institute (ILETRI) from August to December 2020, using the randomized block design in triplicates. The evaluation for pod sucking bug resistance was based on NCT and FCT. Result: The FCT resulted in two genotypes with a consistent moderately resistance level (20-40% of damage intensity) to pod sucking bug based on the pod and seed damage intensity. The NCT method resulted in five genotypes as moderately resistant (20-40% of damage intensity) to pod sucking bug based on the seed damage. The NCT resulted in higher average intensity of pod and seed damage (80.25% and 71.23%, respectively) than the FCT (69.91% and 69.09%, respectively). Two soybean genotypes (Degra/Anjasmoro-1-559 and Anjasmoro/IAC100-2-618) with a consistent moderately resistance level could be used for cultivar improvement in the breeding program. The pod trichome density was suggested to be one of the effective morphological defenses against the pod sucking bug attack.

scholarly journals Resistance of potato genotypes (Solanum spp.) to Bemisia tabaci biotype B

2008 ◽  
Vol 26 (2) ◽  
pp. 221-226 ◽  
Author(s):  
Márcia S Silva ◽  
André L Lourenção ◽  
José Alberto C de Souza-Dias ◽  
Hilário da S Miranda Filho ◽  
Valdir J Ramos ◽  
...  
Keyword(s):  
Free Choice ◽  
Oviposition Preference ◽  
Resistance Mechanism ◽  
Statistical Design ◽  
Adult Emergence ◽  
Choice Test ◽  
Choice Preference ◽  
Randomized Design ◽  
Biotype B ◽  
Bemisia Tabaci Biotype B

The resistance of 24 potato genotypes to B. tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) was evaluated in five greenhouse experiments. The first experiment we evaluated the attractiveness and preference for oviposition in a free-choice test (randomized blocks, 24 treatments, and eight replications). In two other experiments we evaluated no-choice preference for oviposition (randomized blocks, six treatments, and ten replications). The whitefly egg-adult cycle was monitored using a statistical design in randomized blocks with five replications. Trichome density was evaluated in an experiment with 24 treatments and six replications, in a completely randomized design. In the free-choice test, potato genotypes NYL 235-4 and IAC-1966 were the most attractive to adults, while cultivars Achat, Aracy Ruiva, and Monte Bonito presented the lowest number of adults. Also in this assay, cultivars Achat, Ibituaçu, Panda, IAC-1966, and Agata presented the lowest number of eggs, while in the no-choice test, only cultivar Achat and IAC-1966 remained resistant. Consequently, for these two genotypes non-preference is the oviposition resistance mechanism. The egg-adult cycle varied from 21 days (cultivar Panda) to 22.5 days (clones IAC-1966 and NYL 235-4). The adult emergence varied from 91.2% (clone IAC-1966) to 99.3% (cultivar Ibituaçu). Clone NYL 235-4 had the greatest number of simple (ST) and glandular (GT) trichomes; while clone IAC-1966 had the lowest number of ST and, clone IAC-6290, of GT. There were significant correlations between adult attractiveness and oviposition preference; between oviposition preference and ST density; and between oviposition preference and GT density. Considering all characteristics, cultivar Achat was the most resistant to B. tabaci biotype B among all potato genotypes studied, while clone NYL 235-4 proved (past tense) to be susceptible.

The threshold of sweet taste recognition among a sample of Moroccan population

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yasmine Guennoun ◽  
Nada Benajiba ◽  
Khalid Elkari ◽  
Amina Bouziani ◽  
Laila Elammari ◽  
...  
Keyword(s):  
Age Groups ◽  
Sweet Taste ◽  
Test Method ◽  
Recognition Threshold ◽  
Taste Perception ◽  
Choice Test ◽  
Sample Population ◽  
Content Type ◽  
Mean Values ◽  
Moroccan Population

Purpose Sugar consumption in Morocco is high, which is involved in triggering serious health conditions. Hence, assessing the recognition threshold of sweet taste among Moroccans is strongly needed. This study aims to determine the threshold of sweet taste recognition and to evaluate differences by sex, age and body mass index among a sample of Moroccan population. Design/methodology/approach This single-blind trial was conducted among 199 healthy participants to determine the sweet taste. Age and anthropometric characteristics were registered. Nine sucrose solutions of the following concentrations (0; 0.111; 0.333; 1; 3; 9; 27; 81; 243 mmol/L) were prepared. Sweet taste perception thresholds were determined based on the validated 3-alternative forced choice test method. Findings The average age of the sample population was 21.5 ± 26.1. And more than half (51.7%) detected the taste at the concentration of 9 mmol/L, while 91.9% recognized it at a concentration of 27 mmol/L. In terms of sex, the recognition of taste was not different between females and males (p > 0.05). The mean values of the threshold among women were significantly lower (20 ± 20.8 mmol/L) compared to men (23.9 ± 33.2 mmol/L). The age group 49–59 years old had the lowest threshold with a mean of 13.4 ± 10.2 mmol/L, and the groups with BMI in the overweight category had mean of 16.9 ± 18.2 mmol/L. However, no statistical difference was observed among either age groups or BMI categories. Originality/value The sweet recognition threshold among the studied population is high. Therefore, it is strongly recommended to educate the population about the necessity of a progressive reduction of sugar in food items to combat non-communicable disorders.

scholarly journals Oryza glumaepatula, a New Source of Resistance to Meloidogyne graminicola and Histological Characterization of Its Defense Mechanisms

2019 ◽  
Vol 109 (11) ◽  
pp. 1941-1948 ◽  
Author(s):  
Vanessa S. Mattos ◽  
Raycenne R. Leite ◽  
Juvenil E. Cares ◽  
Ana Cristina M. M. Gomes ◽  
Antonio W. Moita ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Resistance Mechanism ◽  
Giant Cells ◽  
Wild Accession ◽  
Sources Of Resistance ◽  
Root Cortex ◽  
Meloidogyne Graminicola ◽  
Significant Damage ◽  
Resistant Accession ◽  
Moderately Resistant

Meloidogyne graminicola causes significant damage to rice fields worldwide. Sources of resistance to M. graminicola reported in Oryza sativa are limited. Resistance to this species has been found in other Oryza species such as O. glaberrima and O. longistaminata. This study aimed to evaluate the reaction of four wild species of Oryza from the Embrapa Rice and Bean Germplasm Bank (Goiás, Brazil) to a pool of M. graminicola populations and determine the resistance mechanism in O. glumaepatula. Two genotypes of O. glaberrima, one of O. alta, three of O. glumaepatula, one of O. grandiglumis, one of O. longistaminata, and one of O. sativa (control) were included in the study. The results showed that O. glumaepatula was highly resistant (reproduction factor [RF] < 1). O. glaberrima, O. alta, and O. grandiglumis were considered moderately resistant. O. longistaminata was susceptible, although values of RF remained lower than the control O. sativa ‘BR-IRGA 410’, considered highly susceptible. Histological observations on the interaction of O. glumaepatula and M. graminicola showed reduced penetration of second-stage juveniles (J2s) when this resistant wild accession was compared with O. sativa. An intense hypersensitivity response-like reaction occurred at 2 days after inoculation in the root cortex of the resistant accession. Few J2s established in the central cylinder, and rare collapsed giant cells were observed surrounded by degenerate females. Fluorescence microscopy in O. glumaepatula revealed giant cells and the female body presumably exhibiting accumulation of phenolic compounds. Our study suggests that wild rice accessions, especially from the AA genotype (e.g., O. glumaepatula), are of great interest for use in future breeding programs with Oryza spp.

Resistance levels of selected rice genotypes to Sitophilus oryzae L. and Rhyzopertha dominica F. infestations

2020 ◽  
Vol 17 ◽  
pp. 39-46
Author(s):  
S.K. Ajao ◽  
K.O. Popoola ◽  
S Mande ◽  
A Togola
Keyword(s):  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Rhyzopertha Dominica ◽  
International Institute ◽  
Rice Varieties ◽  
Resistance Level ◽  
Susceptibility Index ◽  
Grain Damage ◽  
Rice Genotypes ◽  
Moderately Resistant

The need to screen new rice genotypes for resistance to stored product insect pests is important to boost production and availability of rice for food security. Therefore, thirteen rice genotypes and varieties included ten interspecific rice genotypes from two crossed parents Oryza sativa (WAB 56-104) and Oryza barthii (IRGC 106107), the two parents and NERICA8 variety were collected from Africa Rice Center, International Institute of Tropical Agriculture (IITA) Ibadan, to examine their resistance level to infestation by Sitophilus oryzae L. and Rhyzopertha dominica F. The resistance of the varieties were assessed by artificial infestation with 12 unsexed adults each in 10 g of the rice varieties in four replicates under laboratory conditions of 26 ± 2oC temperature and 75 ± 5% relative humidity in a completely randomized design. Number of adult insect emergent, per cent grain damage, percent weight loss of infested samples and index of susceptibility were determined. Correlation analysis between nutritional contents of the varieties and infestation variables were also obtained. Results indicate differential responses of the two insects on the rice genotypes/varieties. The O. barthii parent was resistant, while the O. sativa parent was moderately resistant using the susceptibility index. Of the ten rice genotypes, G4, G3, G1, G7, G2, G10 and G9 were resistant in descending order, while G5 and G6 were moderately resistant, whereas only G8 was susceptible. NERICA8 was also found to be susceptible to infestation. In addition, the resistant grains had lower ash content. Modification in genetic variations and nutritional contents of new rice varieties may be a critical factor in insect resistant genotype pro-grammes to reduce post-harvest losses incurred by farmers. Keywords: Rice resistant genotypes; Rhyzopertha dominica; Oryzae sativa; Oryzae barthii; Sitophilus oryzae; susceptibility index

scholarly journals Resistance to Fludioxonil in Botrytis cinerea Isolates from Blackberry and Strawberry

2014 ◽  
Vol 104 (7) ◽  
pp. 724-732 ◽  
Author(s):  
Xingpeng Li ◽  
Dolores Fernández-Ortuño ◽  
Anja Grabke ◽  
Guido Schnabel
Keyword(s):  
South Carolina ◽  
Botrytis Cinerea ◽  
Resistance Mechanism ◽  
Gray Mold ◽  
Development Of Resistance ◽  
Atp Binding Cassette Transporter ◽  
Glycerol Synthesis ◽  
Increased Sensitivity ◽  
Moderately Resistant ◽  
Gene Alterations

Site-specific fungicides, including the phenylpyrrole fludioxonil, are frequently used for gray mold control but are at risk for the development of resistance. In this study, field isolates that were low-resistant (LR) and moderately resistant (MR) to fludioxonil from blackberry and strawberry fields of North Carolina, South Carolina, and Virginia were characterized. Genes involved in osmoregulation, including bcsak1, BcOS4, bos5, and BRRG-1, were cloned and sequenced to detect potential target gene alterations; however, none were found. A previously described mutation (R632I) in transcription factor Mrr1, which is known to increase the expression of ATP-binding cassette transporter AtrB, was found in MR but not in sensitive (S) or LR isolates. Expression of atrB in MR isolates was ≈200-fold increased compared with an S isolate; however, 30- to 100-fold overexpression was also detected in LR isolates. Both MR isolates exhibited increased sensitivity to salt stress in the form of mycelial growth inhibition at 4% NaCl, indicating a disruption of osmoregulatory processes in those strains. However, the glycerol content was indistinguishable between S, LR, and MR isolates with and without exposure to fludioxonil, suggesting that the glycerol synthesis pathway may not be a part of the resistance mechanism in LR or MR strains. An investigation into the origin of LR and MR isolates from blackberry revealed two insertions in the mrr1 gene consistent with those found in the Botrytis clade group S. The emergence of strains overexpressing atrB in European and now in North American strawberry fields underscores the importance of this resistance mechanism for development of resistance to fludioxonil in Botrytis cinerea.

Inheritance of Glyphosate Resistance in Hairy Fleabane (Conyza bonariensis) from California

Weed Science ◽  
2014 ◽  
Vol 62 (2) ◽  
pp. 258-266 ◽  
Author(s):  
Miki Okada ◽  
Marie Jasieniuk
Keyword(s):  
Resistance Mechanism ◽  
Glyphosate Resistance ◽  
Population Based ◽  
Single Individual ◽  
Resistance Level ◽  
Backcross Population ◽  
Resistant Parent ◽  
Susceptible Population ◽  
Locus Model ◽  
Hairy Fleabane

Inheritance of glyphosate resistance was investigated in hairy fleabane populations from California as part of providing the information needed to predict and manage resistance and to gain insight into resistance mechanism (or mechanisms) present in the populations. Three glyphosate-resistant individuals grown from seed collected from distinct sites near Fresno, CA, were crossed to individuals from the same susceptible population to create reciprocal F1populations. A single individual from each of the F1populations was used to create a backcross population with a susceptible maternal parent, and an F2population. Based on dose response analyses, reciprocal F1populations were not statistically different from each other, more similar to the resistant parent, and statistically different from the susceptible parent, consistent with nuclear control of the trait and dominance to incomplete dominance of resistance over susceptibility in all three crosses. Glyphosate resistance in two of the three crosses segregated in the backcross and the F2populations as a single-locus trait. In the remaining cross, the resistant parent had approximately half the resistance level as the other two resistant parents, and the segregation of glyphosate resistance in backcross and F2populations conformed to a two-locus model with resistance alleles acting additively and at least two copies of the allele required for expression of resistance. This two-locus model of the segregation of glyphosate resistance has not been reported previously. Variation in the pattern of inheritance and the level of resistance indicate that multiple resistance mechanisms may be present in hairy fleabane populations in California.

scholarly journals Oviposition preference and larval performance of sugarcane borer in eight sugarcane genotypes

2017 ◽  
Vol 41 (4) ◽  
pp. 439-446 ◽  
Author(s):  
Guilherme Vieira Pimentel ◽  
Adriano Cirino Tomaz ◽  
Bruno Portela Brasileiro ◽  
Luiz Alexandre Peternelli ◽  
Márcio Henrique Pereira Barbosa
Keyword(s):  
Free Choice ◽  
Early Stage ◽  
Oviposition Preference ◽  
Choice Test ◽  
Larval Performance ◽  
Foliar Injury ◽  
Breeding Programs ◽  
Sugarcane Borer ◽  
Choice Tests ◽  
Late Stages

ABSTRACT The sugarcane borer Diatraea saccharalis Fabr. (Lepidoptera: Crambidae) is one of the most important pests of sugarcane in the Americas. The purpose of this study was to assess multiple resistance traits in eight sugarcane genotypes against D. saccharalis, including five commercial cultivars and three exotic germplasm with potential to serve as resistance sources against this pest. The oviposition preference was assessed by using both free-choice and non-choice tests. The performance of both early stage larvae feeding on the leaves and late stages larvae feeding within the stalks were also assessed. There were differences among genotypes for number of both eggs and egg cluster in the free-choice test while no differences in non-choice test were observed. There were also differences in survival of early stage larvae feeding on the leaves, foliar injury rating and stalk damage. The genotype IM76-228 was the least preferred for oviposition and it seems that leaf width had some influence on adults’ preference rather than greening of the leaves. IM76-228 and RB867515 causes higher mortality of early stage larvae feeding in the stalks while IM76-228 and RB985523 had lower damage in both leaves and stalks. The genotype IM76-228 was the most resistant to D. saccharalis and could serve as genes sources for resistance in sugarcane breeding programs.

Culture of an organophosphorus-resistant strain ofBoophilus microplus(Can.) and an assessment of its resistance spectrum

1966 ◽  
Vol 56 (3) ◽  
pp. 389-405 ◽  
Author(s):  
R. D. Shaw
Keyword(s):  
Resistant Strain ◽  
Specific Resistance ◽  
Dominant Gene ◽  
Resistance Mechanism ◽  
Tick Control ◽  
Boophilus Microplus ◽  
Test Method ◽  
Organophosphorus Insecticides ◽  
Development Of Resistance ◽  
Low Order

Field observations indicated that a strain ofBoophilus microplus(Can.) in the Rockhampton area in Queensland was resistant to an organophosphorus insecticide, dioxathion (applied as Delnav), which had previously controlled it successfully. Ticks of this strain were despatched to the Cooper Technical Bureau in England, where a culture was established and maintained under selective pressure from dioxathion.The non-parasitic stages of the culture were maintained in an incubator under controlled conditions, and the parasitic stages on cattle in a tick rearing house designed for the purpose. Careful security precautions were taken to ensure that there was no dissemination of tick life outside the confines of the culture. The tick rearing house was provided with double doors, the inner ones of which were screened with copper gauze to prevent the possible transmission of anaplasmosis by biting flies.The activities of 23 insecticides against larvae of this strain and larvae of a strain ofB. microplussusceptible to organophosphorus poisoning were compared. The test method was an immersion technique, usually employing the insecticide in the form of an emulsion. Mortality was assessed 17 hours after treatment. These comparisons indicated that the strain was resistant to the organophosphorus insecticides carbophenothion (62 ×), dioxathion (25 ×), diazinon (15 ×), parathion (10×) and a carbamate, carbaryl (38×). It is suggested that these resistances may be due to a specific mechanism effective against these compounds.Nine other organophosphorus insecticides, one carbamate and rotenone were subject to low-order resistance by this strain significant at P ≤0·05. This was considered to be non-specific resistance.Dioxathion had been in use for tick control on the property concerned for four years before resistance was demonstrated. The property is situated in an area where the tick season lasts for ten months. In other parts of the world, dioxathion has been in use againstBoophilusticks for seven years without the development of resistance to it. The length of time resistance has taken to develop suggests that the resistance mechanism is not the expression of a single dominant gene, as has been demonstrated for dieldrin-resistance.The results suggest that resistance to one or more organophosphorus insecticides will not necessarily prevent the use of other members of this wide and diverse group for tick control. Several of the insecticides shown here to be subject to low-order non-specific resistance are known to be effective tick dips, and one of them, ethion, has been used with success against the resistant strain.An interesting corollary of the results was that the organophosphorus thions showed greater activity than their corresponding oxons against the susceptible strain.

Sign in / Sign up

Export Citation Format

Share Document