scholarly journals Common resistance mechanisms are deployed by plants against sap-feeding herbivorous insects: insights from a meta-analysis and systematic review

2021 ◽  
Author(s):  
Daniel J Leybourne ◽  
Gudbjorg I Aradottir
Keyword(s):  
Feeding Behaviour ◽  
Meta Analysis ◽  
Resistance Mechanisms ◽  
Yield Losses ◽  
Feeding Site ◽  
Feeding Duration ◽  
Crop Varieties ◽  
Sap Feeding ◽  
Significant Yield ◽  
Plant Families

Sap-feeding insects cause significant yield losses to the worlds crops, these insects feed using syringe-like mouthparts and electrophysiology can be used to compare feeding behaviour on susceptible and resistant plants to identify the mechanistic processes behind resistant phenotypes. Data extracted from 129 studies, comprising 41 insect species across eight insect taxa and 12 host-plant families representing over 30 species, demonstrates that mechanisms deployed by resistant plants have common consequences on the feeding behaviour of diverse insect groups. We show that insects feeding on resistant plants take longer to establish a feeding site and have their feeding duration suppressed two-fold compared with insects feeding on susceptible plants. Our results reveal that the underlying traits contributing towards resistant phenotypes are conserved across plant families, deployed against taxonomically diverse insect groups, and that the underlying resistance mechanisms are conserved. These findings provide new insight that will be beneficial when developing future crop varieties.

Advances in understanding fungicide resistance in Botrytis cinerea in China

2020 ◽  
Author(s):  
Wenyong Shao ◽  
Youfu Zhao ◽  
Zhonghua Ma
Keyword(s):  
Botrytis Cinerea ◽  
Fungicide Resistance ◽  
Target Genes ◽  
Agricultural Practices ◽  
Resistance Mechanisms ◽  
Gray Mold ◽  
Yield Losses ◽  
Quinone Outside Inhibitor ◽  
Significant Yield ◽  
Fungicide Target

Gray mold, caused by Botrytis cinerea, is a devastating disease causing significant yield losses in various economic plants. Fungicide application is one of the main strategies for management of gray mold; however, B. cinerea has developed resistance to various groups of fungicide. In China, benzimidazole-, dicarboximide-, and quinone outside inhibitor (QoI)-resistant populations of B. cinerea have become dominant. Substitute mutations in fungicide target genes are responsible for resistance in B. cinerea. Based on known resistance mechanisms, molecular methods including loop-mediated isothermal amplification (LAMP) have been developed for rapid detection of resistant isolates of B. cinerea. Since B. cinerea is able to quickly develop resistance to various fungicides, various integrated strategies have been developed, including biological and agricultural practices, to manage fungicide resistance in B. cinerea in the last decade.

Feeding behaviour of the predatory nematodes Laimydorus baldus and Discolaimus major (Nematoda: Dorylaimida)

Nematology ◽  
2005 ◽  
Vol 7 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Anwar L. Bilgrami ◽  
Randy Gaugler
Keyword(s):  
Feeding Behaviour ◽  
Prey Density ◽  
Predation Rate ◽  
Rice Root ◽  
Feeding Site ◽  
Feeding Sites ◽  
Laboratory Conditions ◽  
Feeding Duration ◽  
Feeding Activities ◽  
Rice Root Nematode

Abstract Feeding activities of the predatory nematodes Laimydorus baldus and Discolaimus major were studied under laboratory conditions in relation to temperature (5–40°C), prey density (25–250 individuals), predator starvation (0–12 days) and prey incubation (4–24 h) using the rice root nematode, Hirschmanniella oryzae, as prey. Prey search duration, rate of predation, and the number and duration of predators feeding and aggregating at feeding sites were studied. Discolaimus major killed more prey, and fed and aggregated longer than L. baldus. Predator activities at the feeding site were optimal at 30°C. Predators starved for 6 days required the briefest prey search duration, and remained aggregated at the feeding site for a longer duration. Predators were increasingly efficient at search prey as prey density increased. Prey search and feeding durations were shortest when prey nematodes were incubated between 8–16 h. Predation rate was optimal when prey were incubated for 16 h. Prey search and killing abilities of L. baldus and D. major were governed by temperature, prey density, starvation and prey incubation, and depended upon feeding duration, number of predators feeding and aggregating at the feeding sites.

scholarly journals Comparative Genomics Used to Predict Virulence Factors and Metabolic Genes among Monilinia Species

2021 ◽  
Vol 7 (6) ◽  
pp. 464
Author(s):  
Marina Marcet-Houben ◽  
Maria Villarino ◽  
Laura Vilanova ◽  
Antonieta De Cal ◽  
Jan A. L. van Kan ◽  
...  
Keyword(s):  
Brown Rot ◽  
Weather Conditions ◽  
Genomic Variation ◽  
Disease Development ◽  
Stone Fruits ◽  
Yield Losses ◽  
Future Studies ◽  
Metabolic Genes ◽  
Pome Fruits ◽  
Significant Yield

Brown rot, caused by Monilinia spp., is among the most important diseases in stone fruits, and some pome fruits (mainly apples). This disease is responsible for significant yield losses, particularly in stone fruits, when weather conditions favorable for disease development appear. To achieve future sustainable strategies to control brown rot on fruit, one potential approach will be to characterize genomic variation among Monilinia spp. to define, among others, the capacity to infect fruit in this genus. In the present work, we performed genomic and phylogenomic comparisons of five Monilinia species and inferred differences in numbers of secreted proteins, including CAZy proteins and other proteins important for virulence. Duplications specific to Monilinia were sparse and, overall, more genes have been lost than gained. Among Monilinia spp., low variability in the CAZome was observed. Interestingly, we identified several secondary metabolism clusters based on similarity to known clusters, and among them was a cluster with homology to pyriculol that could be responsible for the synthesis of chloromonilicin. Furthermore, we compared sequences of all strains available from NCBI of these species to assess their MAT loci and heterokaryon compatibility systems. Our comparative analyses provide the basis for future studies into understanding how these genomic differences underlie common or differential abilities to interact with the host plant.

scholarly journals Inheritance of Antibiosis Resistance to the Dectes Stem Borer, Dectes texanus, in Soybean PI165673

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 738
Author(s):  
Lina M. Aguirre-Rojas ◽  
Lawrent L. Buschman ◽  
Brian McCornack ◽  
William T. Schapaugh ◽  
Erin D. Scully ◽  
...  
Keyword(s):  
North America ◽  
Larval Stage ◽  
Stem Borer ◽  
Plant Introduction ◽  
Lower Number ◽  
Soybean Plant ◽  
Yield Losses ◽  
First Instar ◽  
Significant Yield ◽  
Antibiosis Resistance

Dectes texanus larvae girdles the stems of soybean and cultivated sunflowers causing significant yield losses in North America. The soybean Plant Introduction (PI) 165673 exhibits antibiosis resistance to the larval stage. The objectives of this study were: (1) to determine the inheritance of D. texanus resistance in PI165673; (2) evaluate PI165673 antibiosis resistance before 21 d post infestation; (3) evaluate girdling damage in PI16563 at the end of the season. K07-1544/PI165673 F2 and F2:3 populations were tested for resistance to D. texanus in 2011 and 2012, and PI165673 antibiosis resistance and girdling damage were evaluated in 2014. Segregation for resistance to D. texanus and heritability estimates in the F2 and F2:3 populations indicated that resistance was controlled by two genes with dominant and recessive epistasis. Antibiosis evaluations indicated: (1) PI165673 contained lower number of larvae and eggs relative to the number of oviposition punctures at 15 d post infestation; (2) the proportion of first-instar larvae was higher in PI165673 at 15 d post infestation; (3) larvae reach the sixth-instar stage in PI165673. None of the PI165673 plants were girdled at the end of the season. Identification of additional sources of D. texanus resistance is required to impair larval development in the stem.

Fungicide efficacy on tar spot and yield of corn in the Midwestern United States

2022 ◽  
Author(s):  
Darcy E. P. Telenko ◽  
Martin I. Chilvers ◽  
Adam Byrne ◽  
Jill Check ◽  
Camila Rocco Da Silva ◽  
...  
Keyword(s):  
United States ◽  
Growth Stage ◽  
Field Trials ◽  
Corn Belt ◽  
Yield Losses ◽  
Single Application ◽  
Midwestern United States ◽  
Tar Spot ◽  
Significant Yield ◽  
Foliar Fungicide

Tar spot of corn caused by Phyllachora maydis has recently led to significant yield losses in the eastern corn belt of the Midwestern United States. Foliar fungicides containing quinone outside inhibitors(QoI), demethylation inhibitors(DMI), and succinate dehydrogenase inhibitors(SDHI) are commonly used to manage foliar diseases in corn. To mitigate the losses from tar spot thirteen foliar fungicides containing single or multiple modes of action (MOA/FRAC groups) were applied at their recommended rates in a single application at the standard tassel/silk growth stage timing to evaluate their efficacy against tar spot in a total of eight field trials in Illinois, Indiana, Michigan, and Wisconsin during 2019 and 2020. The single MOA fungicides included either a QoI or DMI. The dual MOA fungicides included a DMI with either a QoI or SDHI, and fungicides containing three MOAs included a QoI, DMI, and SDHI. Tar spot severity estimated as the percentage of leaf area covered by P. maydis stroma of the non-treated control at dent growth stage ranged from 1.6 to 23.3% on the ear leaf. Averaged across eight field trials all foliar fungicide treatments reduced tar spot severity, but only prothioconazole+trifloxystrobin, mefentrifluconazole+pyraclostrobin+fluxapyroxad, and mefentrifluconazole+pyraclostrobin significantly increased yield over the non-treated control. When comparing fungicide treatments by the number of MOAs foliar fungicide products that had two or three MOAs decreased tar spot severity over not treating and products with one MOA. The fungicide group that contained all three MOAs significantly increased yield over not treating with a fungicide or using a single MOA.

scholarly journals Response of Sensitive and Resistant Snap Bean Genotypes to Nighttime Ozone Concentration

2020 ◽  
Vol 145 (6) ◽  
pp. 331-339
Author(s):  
Kirsten L. Lloyd ◽  
Donald D. Davis ◽  
Richard P. Marini ◽  
Dennis R. Decoteau
Keyword(s):  
Leaf Age ◽  
Acute Injury ◽  
Yield Response ◽  
Yield Losses ◽  
Foliar Injury ◽  
Snap Bean ◽  
Stirred Tank Reactors ◽  
First Results ◽  
Significant Yield ◽  
The Impact

Effects of nighttime (2000 to 0700 hr) O3 on the pod mass of sensitive (S156) and resistant (R123) snap bean (Phaseolus vulgaris) genotypes were assessed using continuous stirred tank reactors located within a greenhouse. Two concentration-response relationship trials were designed to evaluate yield response to nighttime O3 exposure (10 to 265 ppb) in combination with daytime exposure at background levels (44 and 62 ppb). Three replicated trials tested the impact of nighttime O3 treatment at means of 145, 144, and 145 ppb on yields. In addition, stomatal conductance (gS) measurements documented diurnal variations and assessed the effects of genotype and leaf age. During the concentration-response experiments, pod mass had a significant linear relationship with the nighttime O3 concentration across genotypes. Yield losses of 15% and 50% occurred at nighttime exposure levels of ≈45 and 145 ppb, respectively, for S156, whereas R123 yields decreased by 15% at ≈150 ppb. At low nighttime O3 levels of ≈100 ppb, R123 yields initially increased up to 116% of the treatment that received no added nighttime O3, suggesting a potential hormesis effect for R123, but not for S156. Results from replicated trials revealed significant yield losses in both genotypes following combined day and night exposure, whereas night-only exposure caused significant decreases only for S156. The gS rates ranged from less than 100 mmol·m−2·s−1 in the evening to midday levels more than 1000 mmol·m−2·s−1. At sunrise and sunset, S156 had significantly higher gS rates than R123, suggesting a greater potential O3 flux into leaves. Across genotypes, younger rapidly growing leaves had higher gS rates than mature fully expanded leaves when evaluated at four different times during the day. Although these were long-term trials, gS measurements and observations of foliar injury development suggest that acute injury, occurring at approximately the time of sunrise, also may have contributed to yield losses. To our knowledge, these are the first results to confirm that the relative O3 sensitivity of the S156/R123 genotypes is valid for nighttime exposure.

scholarly journals A BRIEF REVIEW FOR IDENTIFICATION AND DETECTION OF POTATO VIRUSES

2016 ◽  
Vol 1 (1) ◽  
pp. 33 ◽  
Author(s):  
Madiha Urooj ◽  
Uzma Arif ◽  
Anisa Intikhab
Keyword(s):  
Potato Crop ◽  
Abiotic Factors ◽  
Review Article ◽  
Pivotal Role ◽  
Yield Reduction ◽  
Human Consumption ◽  
Yield Losses ◽  
Food Crop ◽  
Potato Viruses ◽  
Significant Yield

Potato is ranked fourth among the food crop and fifth for human consumption. It provides more yield and calories production as compare to cereals. Fungal, viral, viroid, bacteria, nematode, phytoplasmas and abiotic factors play a pivotal role for yield reduction of potato crop. Viruses known to infect potato in Pakistan include PVA, PVM, PVS, PVX, PVY, PLRV and PMTV. Increasing incidence of PVX and PVY in main potato growing areas of Pakistan is getting an alarming position and PLRV has caused significant yield losses. Present review article demonstrate different techniques for diagnostics of major potato viruses.

scholarly journals Weed Mapping in Vineyards Using RGB-D Perception

2021 ◽  
Vol 9 (1) ◽  
pp. 30
Author(s):  
Dimitrios Kateris ◽  
Damianos Kalaitzidis ◽  
Vasileios Moysiadis ◽  
Aristotelis C. Tagarakis ◽  
Dionysis Bochtis
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Field Conditions ◽  
Yield Losses ◽  
Weed Mapping ◽  
Significant Yield ◽  
Different Levels

Weed management is one of the major challenges in viticulture, as long as weeds can cause significant yield losses and severe competition to the cultivations. In this direction, the development of an automated procedure for weed monitoring will provide useful data for understanding their management practices. In this work, a new image-based technique was developed in order to provide maps based on weeds’ height at the inter-row path of the vineyards. The developed algorithms were tested in many datasets from vineyards with different levels of weed development. The results show that the proposed technique gives promising results in various field conditions.

Sign in / Sign up

Export Citation Format

Share Document