Aphid feeding damage causes large losses in susceptible lupin cultivars

2003 ◽  
Vol 43 (11) ◽  
pp. 1357 ◽  
Author(s):  
F. A. Berlandier ◽  
M. W. Sweetingham

The impact of infestation by bluegreen aphid, Acyrthosiphon kondoi, cowpea aphid, Aphis craccivora, and/or green peach aphid, Myzus persicae, on grain production of narrow-leafed lupin (Lupinus angustifolius) and yellow lupin (Lupinus luteus) was assessed at 4 sites in the Western Australian grainbelt. Yield losses caused by naturally occurring aphids on 4 cultivars of narrow-leafed and 2 cultivars of yellow lupins were measured by applying the systemic insecticide imidacloprid as a seed dressing and/or as foliar sprays throughout the plant growth phase and compared with untreated control plots. The extent of damage caused by aphids varied greatly but was significantly influenced by lupin cultivar, and yields for the same treatment combination varied between geographical locations. Bluegreen aphid was the most abundant species wherever large colonies of aphids developed. Yellow lupin Wodjil was the most infested and suffered severe losses in grain yield, whereas narrow-leafed lupin Kalya was largely resistant to aphids and there were negligible losses in grain production from plots not treated for aphids. In a fifth experiment, a single foliar spray of the insecticide pirimicarb controlled abundant aphids and increased yield by as much as 95% (0.65 t/ha) in Wodjil. Lupin growers need to be aware of the potential losses aphids can cause and that applying foliar insecticidal sprays to susceptible cultivars can prevent such losses.

2000 ◽  
Vol 51 (6) ◽  
pp. 721 ◽  
Author(s):  
C. L. Davies ◽  
D. W. Turner ◽  
M. Dracup

This study determined whether the tolerance of yellow lupin to waterlogging, observed in experiments in controlled environments, occurs under field conditions. Of particular interest is the impact of waterlogging on the distribution of roots because lupin is exposed to terminal drought in the south of Western Australia, which in itself can have a profound effect on yield. A field experiment was undertaken in the central grain-growing region of Western Australia near Beverley using hydraulically isolated plots to impose and remove waterlogging in a duplex soil. The responses of root and shoot growth of narrow-leafed and yellow lupin to waterlogging in the field were similar to those observed in the controlled environment experiments. In the field experiment, waterlogging had no effect on seed yield of yellow lupin but reduced it by 61% in narrow-leafed lupin. Waterlogging more than halved the dry weight of narrow-leafed lupin but reduced it by only 19% in yellow lupin. In yellow lupin, yield was 3.4 t/ha with waterlogging and 3.8 t/ha without waterlogging, compared with 1.4 t/ha with waterlogging and 3.5 t/ha without waterlogging in narrow-leafed lupin. Waterlogging had no effect on the harvest index of yellow lupin (0.26) but reduced it from 0.36 to 0.31 in narrow-leafed lupin. The larger effect of waterlogging on the yield of narrow-leafed lupin was mainly attributable to fewer pods. Net root growth ceased during waterlogging in both species. After waterlogging, roots of yellow lupin grew at a similar rate to the controls, whereas roots of narrow-leafed lupin grew at a much slower rate than the controls. Waterlogging halved the root density of yellow lupin at 25 cm depth and almost eliminated the roots of narrow-leafed lupin at this depth. After waterlogging, root production in the surface 10 cm increased to about 0.5 cm/cm 3 in yellow lupin but to 0.2 cm/cm 3 in narrow-leafed lupin. At depth (>20 cm), roots of waterlogged yellow lupin continued to grow while those of waterlogged narrow-leafed lupin grew little, if at all. Yellow lupin tolerated waterlogging in the field better than narrow-leafed lupin because it re-established its root system at depth after waterlogging was removed and it produced more fertile pods.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sampurna Sattar ◽  
Mario T. Martinez ◽  
Andres F. Ruiz ◽  
Wendy Hanna-Rose ◽  
Gary A. Thompson

AbstractNicotinamide (NAM) alters behavior in C. elegans and Drosophila, serving as an agonist of TRPV channels affecting sensory neurons and mimicking the mode of action of insecticides used to control phloem-feeding insects. The impact of NAM on green peach aphid (Myzus persicae) behaviors was assessed in artificial diet assays and foliar applications to Arabidopsis plants. Aphids feeding on artificial diets supplemented with NAM impaired stylet movement causing feeding interruptions and ultimately starvation and death. Aphid feeding behaviors were negatively impacted on NAM sprayed plants at concentrations as low as 2.5 mM leading to increased mortality. In choice assays with NAM sprayed leaves aphids showed clear preference for untreated control leaves. NAM is an intermediate in the NAD salvage pathway that should accumulate in nicotinamidase (nic) mutants. LC-MS analysis showed NAM accumulates 60-fold in nic-1-1 Arabidopsis mutants as compared with Col-0. Aphid reproductive potential was significantly decreased on nic-1-1 mutant plants, resulting in a smaller colony size and arrested population development. The results support the hypothesis that dietary NAM causes behavioral changes in aphids, including altered feeding, reduced reproduction, and increased mortality. NAM is thought to bind to TRPV channels causing overstimulation of sensory neurons in the aphid feeding apparatus.


2021 ◽  
Vol 11 ◽  
Author(s):  
Angel Rain-Franco ◽  
Guilherme Pavan de Moraes ◽  
Sara Beier

Experimental reproducibility in aquatic microbial ecology is critical to predict the dynamics of microbial communities. However, controlling the initial composition of naturally occurring microbial communities that will be used as the inoculum in experimental setups is challenging, because a proper method for the preservation of those communities is lacking. To provide a feasible method for preservation and resuscitation of natural aquatic prokaryote assemblages, we developed a cryopreservation procedure applied to natural aquatic prokaryotic communities. We studied the impact of inoculum size, processing time, and storage time on the success of resuscitation. We further assessed the effect of different growth media supplemented with dissolved organic matter (DOM) prepared from naturally occurring microorganisms on the recovery of the initially cryopreserved communities obtained from two sites that have contrasting trophic status and environmental heterogeneity. Our results demonstrated that the variability of the resuscitation process among replicates decreased with increasing inoculum size. The degree of similarity between initial and resuscitated communities was influenced by both the growth medium and origin of the community. We further demonstrated that depending on the inoculum source, 45–72% of the abundant species in the initially natural microbial communities could be detected as viable cells after cryopreservation. Processing time and long-term storage up to 12 months did not significantly influence the community composition after resuscitation. However, based on our results, we recommend keeping handling time to a minimum and ensure identical incubation conditions for repeated resuscitations from cryo-preserved aliquots at different time points. Given our results, we recommend cryopreservation as a promising tool to advance experimental research in the field of microbial ecology.


Author(s):  
Krystyna Grabowska ◽  
Leszek Kuchar ◽  
Aneta Dymerska

Abstract Prediction of yellow lupin yield (Lupinus luteus L.) for northern Poland using weather- -crop model. The paper presents an analysis of the impact of meteorological factors (solar radiation, maximum, minimum and mean temperature, precipitation) on the development and yield of yellow lupin Parys cultivar in the northern Poland in the years 1987-2008. Using multiple regression methods (linear and quadratic function) created regression equations that were estimated using the coefficients of determination (R2, R2 adj and R2 pred - using the Cross Validation procedure). Selected regression equation used to estimate the yield of yellow lupin, using generated - by means of model WGENK - daily values of global radiation, maximum and minimum temperature, precipitation, and climate change scenario GISS Model E for Central Europe. Examined dependencies weather-yield of lupine seeds (cultivar Parys) allowed the application of the chosen model to forecast yields from the time when the values are independent variables in the model by the end of the growing season. The comparison of distributions of actual and simulated yields shows that real yields are slightly (by 0.06 t·ha-1) higher than those generated for 2 × CO2 conditions.


Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 471
Author(s):  
Camino Gutiérrez-Corbo ◽  
Bárbara Domínguez-Asenjo ◽  
María Martínez-Valladares ◽  
Yolanda Pérez-Pertejo ◽  
Carlos García-Estrada ◽  
...  

Diseases caused by trypanosomatids (Sleeping sickness, Chagas disease, and leishmaniasis) are a serious public health concern in low-income endemic countries. These diseases are produced by single-celled parasites with a diploid genome (although aneuploidy is frequent) organized in pairs of non-condensable chromosomes. To explain the way they reproduce through the analysis of natural populations, the theory of strict clonal propagation of these microorganisms was taken as a rule at the beginning of the studies, since it partially justified their genomic stability. However, numerous experimental works provide evidence of sexual reproduction, thus explaining certain naturally occurring events that link the number of meiosis per mitosis and the frequency of mating. Recent techniques have demonstrated genetic exchange between individuals of the same species under laboratory conditions, as well as the expression of meiosis specific genes. The current debate focuses on the frequency of genomic recombination events and its impact on the natural parasite population structure. This paper reviews the results and techniques used to demonstrate the existence of sex in trypanosomatids, the inheritance of kinetoplast DNA (maxi- and minicircles), the impact of genetic exchange in these parasites, and how it can contribute to the phenotypic diversity of natural populations.


Marine Drugs ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 196
Author(s):  
Muhammad Bilal ◽  
Leonardo Vieira Nunes ◽  
Marco Thúlio Saviatto Duarte ◽  
Luiz Fernando Romanholo Ferreira ◽  
Renato Nery Soriano ◽  
...  

Naturally occurring biological entities with extractable and tunable structural and functional characteristics, along with therapeutic attributes, are of supreme interest for strengthening the twenty-first-century biomedical settings. Irrespective of ongoing technological and clinical advancement, traditional medicinal practices to address and manage inflammatory bowel disease (IBD) are inefficient and the effect of the administered therapeutic cues is limited. The reasonable immune response or invasion should also be circumvented for successful clinical translation of engineered cues as highly efficient and robust bioactive entities. In this context, research is underway worldwide, and researchers have redirected or regained their interests in valorizing the naturally occurring biological entities/resources, for example, algal biome so-called “treasure of untouched or underexploited sources”. Algal biome from the marine environment is an immense source of excellence that has also been demonstrated as a source of bioactive compounds with unique chemical, structural, and functional features. Moreover, the molecular modeling and synthesis of new drugs based on marine-derived therapeutic and biological cues can show greater efficacy and specificity for the therapeutics. Herein, an effort has been made to cover the existing literature gap on the exploitation of naturally occurring biological entities/resources to address and efficiently manage IBD. Following a brief background study, a focus was given to design characteristics, performance evaluation of engineered cues, and point-of-care IBD therapeutics of diverse bioactive compounds from the algal biome. Noteworthy potentialities of marine-derived biologically active compounds have also been spotlighted to underlying the impact role of bio-active elements with the related pathways. The current review is also focused on the applied standpoint and clinical translation of marine-derived bioactive compounds. Furthermore, a detailed overview of clinical applications and future perspectives are also given in this review.


2019 ◽  
Vol 33 (6) ◽  
pp. 827-832
Author(s):  
Pingyuan Zhang ◽  
Bruce E. Branham

AbstractExperiments were conducted to evaluate the impact of spray volume, nozzle type, adjuvants, the presence of dew, and their interactions on foliar retention of creeping bentgrass. Tartrazine, a common food dye, was used as a tracer in this study. Increasing spray volume from 95 L ha−1 to 1,500 L ha−1 decreased foliar retention efficiency from 98% to approximately 85%. Compared with flat-fan nozzles, air-induction nozzles delivered similar retention efficiency at all spray volumes evaluated. However, flat-fan nozzles provided higher uniformity and more thorough coverage. Adding nonionic surfactants, organosilicone adjuvants, or methylated seed oils at typical concentrations yielded retention efficiency of approximately 90% to 93% regardless of spray volumes. In contrast, with water alone, increasing spray volume reduced retention efficiency from 95.9% to 87.3%. Simulated dew applied at 1,950 L ha−1 increased retention efficiency by approximately 3% when spray application volume was 190 L ha−1, while no difference was observed at 750 L ha−1. The presence of dew reduced the impact of adjuvants on retention efficiency. Large quantities of dew, 3,800 L ha−1, did reduce retention efficiency.


1996 ◽  
Vol 42 (8) ◽  
pp. 1345-1349 ◽  
Author(s):  
J B Silkworth ◽  
J F Brown

Abstract Humans are exposed daily to low concentrations of many different chemical substances, natural and some man-made. Although many of these substances can be toxic at high levels, typical exposures are far below the effect levels. The responses produced by man-made aromatic hydrocarbon receptor agonists, such as dioxins, polychlorinated dibenzofurans, coplanar polychlorinated biphenyls, and polycyclic aromatic hydrocarbons, are also produced, often to greater extents [corrected], by naturally occurring constituents of fried meat, cabbage, broccoli, cauliflower, cocoa, and curry. Our society seems to be concerned about the health risks associated only with the synthetic chemicals, regardless of their proportional contribution to the total agonist activity, and regulates on the basis of such concerns. It would be more protective of the public health to determine acceptable concentrations for each type of response, regardless of the origin of the inducing agent, and issue advisories or regulations accordingly.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 321
Author(s):  
Stefan Cristian Prazaru ◽  
Giulia Zanettin ◽  
Alberto Pozzebon ◽  
Paola Tirello ◽  
Francesco Toffoletto ◽  
...  

Outbreaks of the Nearctic leafhopper Erasmoneura vulnerata represent a threat to vinegrowers in Southern Europe, in particular in North-eastern Italy. The pest outbreaks are frequent in organic vineyards because insecticides labeled for organic viticulture show limited effectiveness towards leafhoppers. On the other hand, the naturally occurring predators and parasitoids of E. vulnerata in vineyards are often not able to keep leafhopper densities at acceptable levels for vine-growers. In this study, we evaluated the potential of two generalist, commercially available predators, Chrysoperla carnea and Orius majusculus, in suppressing E. vulnerata. Laboratory and semi-field experiments were carried out to evaluate both species’ predation capacity on E. vulnerata nymphs. The experiments were conducted on grapevine leaves inside Petri dishes (laboratory) and on potted and caged grapevines (semi-field); in both experiments, the leaves or potted plants were infested with E. vulnerata nymphs prior to predator releases. Both predator species exhibited a remarkable voracity and significantly reduced leafhopper densities in laboratory and semi-field experiments. Therefore, field studies were carried out over two growing seasons in two vineyards. We released 4 O. majusculus adults and 30 C. carnea larvae per m2 of canopy. Predator releases in vineyards reduced leafhopper densities by about 30% compared to the control plots. Results obtained in this study showed that the two predators have a potential to suppress the pest density, but more research is required to define appropriate predator–prey release ratios and release timing. Studies on intraguild interactions and competition with naturally occurring predators are also suggested.


2002 ◽  
Vol 57 (9-10) ◽  
pp. 811-816 ◽  
Author(s):  
Yasufumi Katagiri ◽  
Yasuyuki Hashidoko ◽  
Satoshi Tahara

Quantification of the flavonoids in yellow lupin (Lupinus luteus; Leguminosae) seedlings revealed that a flavone glucoside, 7-O-β-(2-O-β-rhamnosyl)glucosyl-4′,5,7-trihydroxyflavone (apigenine 7-O-β-neohesperidoside), is rich in the epicotyl and cotyledon. In hypocotyls and roots, 8-C-β-glucosyl-4′,5,7-trihydroxyisoflavone (genistein 8-C-β-glucoside) was a predominant flavonoid constituent. The roles of the localized flavonoids are briefly discussed relating to defense against biotic and abiotic external stresses.


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