Distribution of the Specialist Aphid Uroleucon nigrotuberculatum (Homoptera: Aphididae) in Response to Host Plant Semiochemical Induction by the Gall Fly Eurosta solidaginis (Diptera: Tephritidae)

2019 ◽  
Vol 48 (5) ◽  
pp. 1138-1148
Author(s):  
Austin M Thomas ◽  
Ray S Williams ◽  
Robert F Swarthout
Keyword(s):  
Host Plant ◽  
Field Experiments ◽  
Plant Biomass ◽  
Spatial Relationship ◽  
Host Recognition ◽  
Eurosta Solidaginis ◽  
Gall Tissue ◽  
Tall Goldenrod ◽  
Uroleucon Nigrotuberculatum ◽  
Consistent Increase

AbstractMany plants use terpenoids and other volatile compounds as semiochemicals. Reception of plant volatiles by conspecifics may trigger a defensive phytochemical response. These same compounds can also function as host recognition signals for phytophagous insects. In this experiment, we find that when the specialist gall-forming fly Eurosta solidaginis (Fitch; Diptera: Tephritidae) attacks its tall goldenrod (Solidago altissima (L.; Asterales: Asteraceae)) host plant, the fly indirectly induces a phytochemical response in nearby tall goldenrod plants. This phytochemical response may, in turn, act as a positive signal attracting the goldenrod specialist aphid Uroleucon nigrotuberculatum (Olive; Hemiptera: Aphididae). Laboratory-based experiments exposing ungalled tall goldenrod plants to the volatiles released by E. solidaginis galls demonstrated a consistent increase in foliar terpenoid concentrations in ungalled plants. Analysis of tall goldenrod stem and gall tissue chemistry revealed induction of terpenoids in gall tissue, with a simultaneous decrease in green leaf volatile concentrations. Field experiments demonstrated a consistent spatial relationship in tall goldenrod foliar terpenoid concentrations with distance from an E. solidaginis gall. Both laboratory and field experiments establish consistent induction of the terpene β-farnesene, and that this compound is a strong positive predictor of U. nigrotuberculatum aphid presence on goldenrod plants along with plant biomass and several other foliar terpenoids. These findings suggest E. solidaginis induced phytochemistry, especially β-farnesene, may be acting as a kairomone, driving aphid distribution in the field.

scholarly journals Large-scale transcriptomics to dissect 2 years of the life of a fungal phytopathogen interacting with its host plant

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Elise J. Gay ◽  
Jessica L. Soyer ◽  
Nicolas Lapalu ◽  
Juliette Linglin ◽  
Isabelle Fudal ◽  
...  
Keyword(s):  
Host Plant ◽  
Large Scale ◽  
Field Experiments ◽  
Plant Residues ◽  
Plant Infection ◽  
Effector Genes ◽  
Controlled Conditions ◽  
Niche Adaptation ◽  
Depth Analysis ◽  
Fungal Genes

Abstract Background The fungus Leptosphaeria maculans has an exceptionally long and complex relationship with its host plant, Brassica napus, during which it switches between different lifestyles, including asymptomatic, biotrophic, necrotrophic, and saprotrophic stages. The fungus is also exemplary of “two-speed” genome organisms in the genome of which gene-rich and repeat-rich regions alternate. Except for a few stages of plant infection under controlled conditions, nothing is known about the genes mobilized by the fungus throughout its life cycle, which may last several years in the field. Results We performed RNA-seq on samples corresponding to all stages of the interaction of L. maculans with its host plant, either alive or dead (stem residues after harvest) in controlled conditions or in field experiments under natural inoculum pressure, over periods of time ranging from a few days to months or years. A total of 102 biological samples corresponding to 37 sets of conditions were analyzed. We show here that about 9% of the genes of this fungus are highly expressed during its interactions with its host plant. These genes are distributed into eight well-defined expression clusters, corresponding to specific infection lifestyles or to tissue-specific genes. All expression clusters are enriched in effector genes, and one cluster is specific to the saprophytic lifestyle on plant residues. One cluster, including genes known to be involved in the first phase of asymptomatic fungal growth in leaves, is re-used at each asymptomatic growth stage, regardless of the type of organ infected. The expression of the genes of this cluster is repeatedly turned on and off during infection. Whatever their expression profile, the genes of these clusters are enriched in heterochromatin regions associated with H3K9me3 or H3K27me3 repressive marks. These findings provide support for the hypothesis that part of the fungal genes involved in niche adaptation is located in heterochromatic regions of the genome, conferring an extreme plasticity of expression. Conclusion This work opens up new avenues for plant disease control, by identifying stage-specific effectors that could be used as targets for the identification of novel durable disease resistance genes, or for the in-depth analysis of chromatin remodeling during plant infection, which could be manipulated to interfere with the global expression of effector genes at crucial stages of plant infection.

Acrolein Reduces Biomass and Seed Production of Potamogeton pectinatus in Irrigation Channels

2004 ◽  
Vol 18 (3) ◽  
pp. 605-610 ◽  
Author(s):  
Diego J. Bentivegna ◽  
Osvaldo A. Fernández ◽  
María A. Burgos
Keyword(s):  
Plant Growth ◽  
Field Experiments ◽  
Plant Biomass ◽  
Treatment Plant ◽  
Irrigation District ◽  
Potamogeton Pectinatus ◽  
Individual Plant ◽  
Plant Weight ◽  
The Third ◽  
Irrigation Channels

Chemical weed control with acrolein has been shown to be a lower cost method for reducing submerged plant biomass of sago pondweed in the irrigation district of the Lower Valley of Rio Colorado, Argentina (39°10′S–62°05′W). However, no experimental data exist on the effects of the herbicide on plant growth and its survival structures. Field experiments were conducted during 3 yr to evaluate the effect of acrolein on growth and biomass of sago pondweed and on the source of underground propagules (i.e., rhizomes, tubers, and seeds). Plant biomass samples were collected in irrigation channels before and after several herbicide treatments. The underground propagule bank was evaluated at the end of the third year. Within each treatment, plant biomass was significantly reduced by 40 to 60% in all three study years. Rapid new plant growth occurred after each application; however, it was less vigorous after repeated treatments. At the end of the third year at 3,000 m downstream from the application point, plant biomass at both channels ranged from 34 to 3% of control values. Individual plant weight and height were affected by acrolein treatments, flowering was poor, and seeds did not reach maturity. After 3 yr, acrolein did not reduce the number of tubers. However, they were significantly smaller and lighter. Rhizomes fresh weight decreased by 92%, and seed numbers decreased by 79%. After 3 yr of applications, operational functioning of the channels could be maintained with fewer treatments and lower concentrations of acrolein.

scholarly journals Influence of Rice Husk Biochar and Compost Amendments on Salt Contents and Hydraulic Properties of Soil and Rice Yield in Salt-Affected Fields

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1101
Author(s):  
Nguyen Thi Kim Phuong ◽  
Chau Minh Khoi ◽  
Karl Ritz ◽  
Tran Ba Linh ◽  
Dang Duy Minh ◽  
...  
Keyword(s):  
Rice Husk ◽  
Crop Production ◽  
Hydraulic Properties ◽  
Field Experiments ◽  
Plant Biomass ◽  
Total Porosity ◽  
Available P ◽  
Exchangeable Sodium ◽  
Compost Amendments ◽  
Rice Husk Biochar

Soil salinity may damage crop production. Besides proper management of irrigation water, salinity reduction can be achieved through soil amendment. The objectives of this study were to evaluate the effects of rice husk biochar and compost amendments on alleviation of salinity and rice growth. Field experiments were conducted at two salt-affected paddy rice fields located in distinct sites for five continuous crops. Treatments, with four replicates, consisted of continuous three rice crops per year (RRR), two rice crops rotated with fallow in spring–summer crop (FRR), FRR plus compost at 3 Mg ha−1 crop−1 (FRR + Comp), and biochar at 10 Mg ha−1 crop−1 (FRR + BC). Salt contents and hydraulic properties of soils, plant biomass, and plant uptake of cations were investigated. Soil bulk density (BD), exchangeable sodium (Na+), and exchangeable sodium percentage (ESP) were reduced remarkably by biochar application. Biochar application significantly increased other soil properties including total porosity, saturated hydraulic conductivity (Ksat), soluble and exchangeable potassium (K+), K+/Na+ ratio, available P, and total C. Compost application also improved BD, total porosity, and available P, but not exchangeable Na+ and ESP. Total aboveground biomass of rice showed a trend of FRR + BC > FRR + Comp > FRR > RRR. Relatively higher K+ uptake and lower Na+ uptake in rice straw in FRR + BC resulted in a significant two times higher K+/Na+ ratio over other treatments. Our results highlight that biochar amendment is a beneficial option for reducing ESP and providing available K+ and P under salinity-affected P-deficient conditions, hence improving straw biomass.

Age of peat-based lupin and chickpea inoculants in relation to quality and efficacy

2005 ◽  
Vol 45 (3) ◽  
pp. 183 ◽  
Author(s):  
E. J. Hartley ◽  
L. G. Gemell ◽  
J. F. Slattery ◽  
J. G. Howieson ◽  
D. F. Herridge
Keyword(s):  
Host Plant ◽  
Colony Size ◽  
Field Experiments ◽  
Research Unit ◽  
Nutrient Agar ◽  
Best Fit ◽  
Legume Inoculants ◽  
Over Time ◽  
Rhizobial Inoculants

Extension of the current 12-month expiry of rhizobial inoculants in Australia to 18 months would have commercial benefits for the manufacturers and resellers. The dilemma, however, is that numbers of rhizobia in the inoculants decline over time and individual cells may lose efficacy. The research undertaken in this study shows the effect of lupin and chickpea inoculant age (i.e. 0, 6, 12, 15 and 18 months old) on numbers of rhizobia, rhizobial cell characteristics and efficacy. For the latter, assessments included colony size on plates, survival on inoculated beads, and infectiveness and effectiveness in field experiments at 3 sites. Assessment of commercially produced inoculants at the Australian Legume Inoculants Research Unit (ALIRU) laboratory indicated that, on average, chickpea and lupin inoculants had counts of about log10 9.6 when fresh, delivering >log10 6 rhizobia/seed. At 12 months, the average counts had fallen to log10 9.4, delivering slightly less than log10 6 rhizobia/seed. By 18 months, average counts were log10 9.3, delivering log10 5.9 rhizobia/seed. The lines of best fit indicated decline rates of 0.0005 log10 units/day. We found no evidence that the rhizobia in the older inoculants (i.e. >12 months old) had lost any ability to grow on nutrient agar, survive on inoculated beads, and nodulate and fix nitrogen with the host plant. While the chickpea and lupin inoculants produced currently in Australia are as efficacious after 18 months of storage at 4°C as they are when fresh, efficacy of other inoculant types may fall below acceptable levels at <12 months.

scholarly journals Assessment of the Effect of the Mineral Fertilization System on the Nutritional Status of Maize Plants and Grain Yield Prediction

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 404
Author(s):  
Renata Gaj ◽  
Piotr Szulc ◽  
Idzi Siatkowski ◽  
Hubert Waligóra
Keyword(s):  
Nutritional Status ◽  
Grain Yield ◽  
Field Experiments ◽  
Plant Biomass ◽  
Calcium Content ◽  
Development Stage ◽  
Mineral Fertilization ◽  
Stay Green ◽  
Maize Varieties ◽  
The Impact

A strict field experiment with maize was carried out in the years 2009–2011 at the Experimental Station of the Poznań University of Life Sciences. The impact of mineral fertilization levels on the nutritional status of plants at an early development stage 5–6 leaves (BBCH 15/16) was assessed, as well as the possibility of using biomass and the current state of nutrient supply to predict grain yield. The adopted assumptions were verified on the basis of field experiments with nine variants of mineral fertilization and two maize varieties (EURALIS Semences, Lescar, France) (ES Palazzo and ES Paroli SG—“stay-green” (SG)). Regardless of the variety tested, the plants were under-nutritioned with calcium and magnesium. Plant nutritional status and the accumulation of minerals at the BBCH 15/16 stage were the main factors determining the variability of maize grain yields. In addition, it was shown that maize biomass in the BBCH 15/16 stage, calcium content and the N:K ratio significantly determined grain yield of traditional variety. The yield of the “stay-green” hybrid was largely shaped by plant biomass in the BBCH 15/16 stage, potassium, calcium, magnesium contents and N:Mg ratio. Regression analysis showed that grain yield of the tested maize varieties was determined by plant biomass and its content from 59% to 69%.

scholarly journals Root endophytic fungi impact host plant biomass and respond to plant composition at varying spatio-temporal scales

2020 ◽  
Vol 44 ◽  
pp. 100907 ◽  
Author(s):  
Nathan Vannier ◽  
Anne-Kristel Bittebiere ◽  
Cendrine Mony ◽  
Philippe Vandenkoornhuyse
Keyword(s):  
Host Plant ◽  
Endophytic Fungi ◽  
Plant Biomass ◽  
Plant Composition ◽  
Temporal Scales ◽  
Root Endophytic Fungi ◽  
Spatio Temporal

Effect of Different Irrigation Sources on Growth, Yield and Heavy Metals Accumulation in Tomato and Okra

2019 ◽  
pp. 10-19 ◽  
Author(s):  
Safina Naz ◽  
Muhammad Akbar Anjum ◽  
Sakeena Tul Ain Haider
Keyword(s):  
Heavy Metals ◽  
Field Experiments ◽  
Plant Biomass ◽  
Fruit Size ◽  
Growth Yield ◽  
Sewage Water ◽  
Growth And Yield ◽  
Well Water ◽  
Tube Well ◽  
Edible Parts

Field experiments were conducted to investigate the effects of different irrigation sources (canal, tube-well and sewage) on growth, yield and heavy metal uptake of two summer vegetables i.e. tomato and okra. Growth attributes (plant height, number of leaves, relative leaf chlorophyll content and leaf area) and yield components (number of fruits / pods per plant and fruit size) of okra and tomato were significantly increased with sewage water application. Lesser growth and yield of the studied vegetables was recorded with tube-well water. Use of sewage water improved total yields and fresh and dry plant biomass production of both the vegetables. Significantly higher and lower lead (Pb), copper (Cu), cadmium (Cd), nickel (Ni), chromium (Cr) and iron (Fe) contents were recorded in edible parts of the sewage and tube-well water irrigated vegetables, respectively. Edible parts (tomato fruits and okra pods) of the sewage water irrigated vegetables exhibited heavy metals contents above the maximum permissible limits. Leaf and root samples of the sewage water irrigated tomato and okra also contained significantly greater metals contents as compared to those irrigated with canal and tube-well water. It is concluded that vegetables irrigated with sewage water produced greater yields but these were found contaminated with heavy metals.

scholarly journals Role of Host Plant Phenology in Host Use by Eurosta solidaginis (Diptera: Tephritidae) on Solidago (Compositae)

1993 ◽  
Vol 22 (2) ◽  
pp. 388-396 ◽  
Author(s):  
Susan Torgerson How ◽  
Warren G. Abrahamson ◽  
Timothy P. Craig
Keyword(s):  
Host Plant ◽  
Plant Phenology ◽  
Host Use ◽  
Eurosta Solidaginis
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