scholarly journals Preference of the Waterlily Aphid, Rhopalosiphum nymphaeae (Hemiptera: Aphididae) on Four Hostplants

2021 ◽  
Vol 25 (1) ◽  
pp. 21
Author(s):  
Ilmam Zul Fahmi ◽  
Nugroho Susetya Putra ◽  
Siwi Indarti ◽  
Satoru Sato

Waterlily aphid Rhopalosiphum nymphaeae is one of the aphids that have many hosts, including Azolla filiculoides, Limnobium laevigatum, Monochoria vaginalis and Spirodela polyrhiza. The aim of this study was to study the effect of host shift and confirm the results  of previous studies on the effect of nitrogen and carbon factors among A. filiculoides, L. laevigatum, M. vaginalis and S. polyrhiza on the level of aphid preference and number of offspring. Analysis of the nitrogen and carbon content of plants was also carried out to confirm the preference and number of offspring produced by aphids. The study began with maintaining aphids on the four tested hosts, up to the 4th generation. Twenty five individuals were randomly selected from each host, then released on the inner wall of the plastic container (14 x 7.5 x 15 cm3) which was filled with four hosts arranged side by side. Observations were made every 24 hours up to 97 hours starting from the first hour after treatment. Observations after 97 hours showed that waterlily aphids imago preferred L. laevigatum the most (49.28%), then on M. vaginalis (20.43%), S. polyrhiza (16.33%), and A. filiculoides (1.75%). Meanwhile, the number of offspring produced by each group of aphids that selected on four hosts were: 46.65 individuals on L. laevigatum, 37.8 individuals on M. vaginalis, 19 individuals on S. polyrhiza, and 0.6 individuals on A. filiculoides. The analysis showed that the highest nitrogen content was found in M. vaginalis (4.16%), followed by S. polyrhiza (3.71%), L. laevigatum (2.33%), and A. filiculoides (2.08%).

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2256
Author(s):  
Yoichi Sato ◽  
Yutaro Kinoshita ◽  
Miho Mogamiya ◽  
Eri Inomata ◽  
Masakazu Hoshino ◽  
...  

The green macroalga Ulva prolifera has a number of variants, some of which are asexual (independent from sexual variants). Although it has been harvested for food, the yield is decreasing. To meet market demand, developing elite cultivars is required. The present study investigated the genetic stability of asexual variants, genotype (hsp90 gene sequences) and phenotype variations across a temperature gradient (10–30 °C) in an apomictic population. Asexual variants were collected from six localities in Japan and were isolated as an unialgal strain. The hsp90 gene sequences of six strains were different and each strain included multiple distinct alleles, suggesting that the strains were diploid and heterozygous. The responses of growth and sporulation versus temperature differed among strains. Differences in thermosensitivity among strains could be interpreted as the result of evolution and processes of adaptation to site-specific environmental conditions. Although carbon content did not differ among strains and cultivation temperatures, nitrogen content tended to increase at higher temperatures and there were differences among strains. A wide variety of asexual variants stably reproducing clonally would be advantageous in selecting elite cultivars for long-term cultivation. Using asexual variants as available resources for elite cultivars provides potential support for increasing the productivity of U. prolifera.


2021 ◽  
Vol 9 ◽  
Author(s):  
Jinniu Wang ◽  
Jing Gao ◽  
Yan Wu ◽  
Bo Xu ◽  
Fusun Shi ◽  
...  

Phenotypic plasticity among natural plant populations is a species-specific ecological phenomenon of paramount importance that depends on their life forms, development stages, as well as environmental factors. While this phenomenon is broadly understood, it has hardly been observed in nature. This study aimed at understanding phenotypic plasticity and ecological adaptability in three shrubs (Salix etosia, Rubus setchuenensis, and Hydrangea aspera) affected by potential environmental variables after deforesting in sparse Larix spp. forest and tall shrub mixed secondary forests. Soil organic carbon content, total nitrogen content, and available nitrogen content were greater outside the forests, contrary to other measured factors whose availability was higher in the forest interiors. In case of leaf traits and stoichiometric indicators, there were significant interactions of leaf area (LA), leaf dry matter (DW), specific leaf area (SLA), and leaf phosphorus content (LPC) between shrub species and heterogeneous environments (P < 0.05) but not for leaf C/N, N/P, and C/P. Principal components analysis (PCA) indicated that soil temperature, pH value, soil carbon content, soil nitrogen content, and MBC and MBN mainly constituted the first component. Summarized results indicated that TB and leaf C/P of S. etosia were significantly correlated with three principal components, but only marginal significant correlations existed between R/S and relevant components. SLA and R/S of R. setchuenensis had marginal significant relationships with independent variables. Both SLA and TB of H. aspera were significantly correlated with three principal components. Based on the pooled values of leaf functional traits and leaf stoichiometric indicators, R. setchuenensis (vining type) had better leaf traits plasticity to adapt to a heterogeneous environment. In descending order, the ranks of biomass allocation plasticity index of three shrubs were H. aspera (bunch type), R. setchuenensis (vining type), and S. etosia (erect type). The highest integrated plasticity values of leaf traits and biomass allocation was observed in H. aspera (bunch type), followed by R. setchuenensis, and by S. etosia with less adaptive plasticity in heterogeneous environments.


Agropedology ◽  
2019 ◽  
Vol 27 (1) ◽  
Author(s):  
R. Srinivasan ◽  
◽  
D. C. Nayak ◽  
S. K. Singh ◽  
◽  
...  

The distribution of nutrients were studied in six soil management units identified viz., Chandipur, Biprodaspur, Pathankhali, Manmathanagar-I, Manmathanagar-II and Bhupendranagar of Gosaba block (part) of sundarbans ecosystem. Data indicated that the soils were strongly acidic (< 4.5) to neutral in reaction and associated with marginal to severe salinity (> 13.3 dS m-1). The organic carbon content ranged from 0.67 to 1.66% in surface and 0.15 to 3.44% in sub-soils. The available nitrogen content varied from 90 to 502 kg ha-1 and it changed significantly with depth. The available phosphorus varied from 0.5 to 24.7 kg ha-1. Available potassium and sulphur in soils are very high, ranging from 178 to 572 kg ha-1 and 25 to 706 mg kg-1 respectively. DTPA -Fe and Mn varied from 18.9 to 336 and 2.17 to 37.6 mg kg-1 in soils being higher in sub-surface horizons, and DTPA- Zn and Cu ranged 0.27 to 4.73 and 0.63 to 14.5 mg kg-1 respectively.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
A. M. Dadile ◽  
O. A. Sotannde ◽  
B. D. Zira ◽  
M. Garba ◽  
I. Yakubu

Fuelwood species are a crucial part of the ecosystem; they provide energy for cooking, heating, and lightening for both domestic and industrial uses. As a result of their value, there is a need for frequent evaluation of elemental and chemical compositions for management and conservation purposes. Since fuelwood is the most common and cheapest source of energy in both rural and urban areas in northern Nigeria, the study area is facing serious challenges due to indiscriminate felling of trees for energy use, irrespective of species quality for combustion. Therefore, ten fuelwood species were selected for this study. The selected trees were harvested at Dbh level, replicated three times. Four fuel materials were obtained from each tree sample; these include wood without bark (100% wood sample), wood with 5% bark inclusion, wood with 10% bark inclusion, and whole bark samples and they were evaluated for their inherent elemental and chemical compositions by employing ASTM and TAPPI methods. The results showed that there were significant differences in the tree species and fuel material types obtained from all the ten fuelwood species used. The results of carbon content ranges from 49.54% in A. sieberiana to 50.98% in A. leiocarpus. Meanwhile, the addition of 5% and 10% bark reduces carbon content of wood by 1.25% and 2.74%, respectively. Nitrogen content ranged from 0.31% in A. leiocarpus to 1.00% in A. sieberiana. Among the fuel materials used, isolated bark contained approximately 0.45% nitrogen content compared with wood without bark. Among the tree species, hydrogen content ranged from 3.99% in P. reticulatum to 4.66% in C. arereh. The variation in sulphur contents ranged from 0.24% in C. arereh to 0.93% in A. sieberiana. Lignin content ranged from 10.68% in A. sieberiana to 25.39% in A. leiocarpu and extractive content values ranged from 7.31% in A. leiocarpus to 19.33% in P. reticulatum. Meanwhile, the fuelwood species observed in this study with higher percentage of carbon, hydrogen, and lignin and lower nitrogen and sulphur and extractive content possessed quality fuel value and thereby were encouraged to be incorporated in fuelwood plantation establishment programs (A. leiocarpus, C. molle, C. arereh, and B. aegyptiaca). Lower energy fuelwood species should be allowed for environmental amelioration and carbon sequestration. However, bark contents should be removed for better heating and low ash production during combustion.


2014 ◽  
Vol 1073-1076 ◽  
pp. 1743-1750
Author(s):  
Wei Guo ◽  
Zhong Qing Zhang ◽  
Jin Hua Liu ◽  
Ping Zhu ◽  
Jing Min Yang

Long-term experiment of Gongzhuling base for the study through three treatments(1)NPK: NPK fertilizer; (2)N165M: Manure and NPK fertilizer; (3)1.5M+NPK: 1.5Manure and NPK fertilizer, used DSSAT-Century soil model to study the long-term effects of different fertilizer treatments on soil organic carbon, total nitrogen content and the laws of growth and decline. The results show that: long-term application of nitrogen fertilizer can significantly improve crop yields compare with NPK.. Corn production is also affected by climatic conditions, especially in drought years with less precipitation. Larger impact of organic manure on soil organic carbon (SOC)and total nitrogen, SOC content obtained in descending order of 1.5M + N165> N165> N0 by Century model simulation. Soil organic carbon content and nitrogen content has a certain relevance, and the trend is consistent. Organic manure and inorganic fertilizer can significantly reduce soil inorganic nitrogen content and reduce the risk of nitrogen leaching. Through model simulations C / N ratio could be explained: C / N increases indicated an increase of organic carbon faster than organic nitrogen in soil, and changes of soil chronic library SOM2 determined organic carbon content. Therefore we should pay attention to organic manure carbon return level, vigorously promote the use of farmyard manure to improve soil nutrient content.


Author(s):  
V. A. Stefanovich ◽  
S. V. Borisov ◽  
A. V. Stefanovich

The article presents the results on the structure formation of deposited coatings obtained from steel chips P6M5 subjected to diffusion nitrogen-carbon doping. It was found that the diffusion doping with nitrogen-carbon steel chip waste P6M5 carbon content in them varies between 1.75–3.14%, nitrogen – 0.43–1.24%. The phase composition includes phases: a-Fe, M6C, Fe3C, (Cr, Fe)2N1–x, Fe3N, Cr0.63C0.35N0.03, M4(C, N) depending on the temperature and time of diffusion doping. When surfacing these materials in the deposited coating contains carbide-forming elements 8,6–9,3%, carbon 1,04–1,94%, nitrogen 0,08–0,25%. The structure consists of carbide M23S6, martensite and austenite, while the content of austenite in dendrites can reach 70–90%. It is shown that nitrogen doping of the deposited coatings obtained from steel chips P6M5, subjected to saturation with nitrogen-carbon, more effectively increases the amount of austenite in the structure than alloying the deposited coatings with nitrogen ferroalloys.


2021 ◽  
Vol 12 ◽  
Author(s):  
Sylvain Pincebourde ◽  
Jérôme Ngao

Herbivore insects have strong impacts on leaf gas exchange when feeding on the plant. Leaf age also drives leaf gas exchanges but the interaction of leaf age and phloem herbivory has been largely underexplored. We investigated the amplitude and direction of herbivore impact on leaf gas exchange across a wide range of leaf age in the apple tree–apple green aphid (Aphis pomi) system. We measured the gas exchange (assimilation and transpiration rates, stomatal conductance and internal CO2 concentration) of leaves infested versus non-infested by the aphid across leaf age. For very young leaves up to 15 days-old, the gas exchange rates of infested leaves were similar to those of non-infested leaves. After few days, photosynthesis, stomatal conductance and transpiration rate increased in infested leaves up to about the age of 30 days, and gradually decreased after that age. By contrast, gas exchanges in non-infested leaves gradually decreased across leaf age such that they were always lower than in infested leaves. Aphids were observed on relatively young leaves up to 25 days and despite the positive effect on leaf photosynthesis and leaf performance, their presence negatively affected the growth rate of apple seedlings. Indeed, aphids decreased leaf dry mass, leaf surface, and leaf carbon content except in old leaves. By contrast, aphids induced an increase in leaf nitrogen content and the deviation relative to non-infested leaves increased with leaf age. Overall, the impacts of aphids at multiple levels of plant performance depend on leaf age. While aphids cause an increase in some leaf traits (gas exchanges and nitrogen content), they also depress others (plant growth rate and carbon content). The balance between those effects, as modulated by leaf age, may be the key for herbivory mitigation in plants.


Author(s):  
J.A. Lindley

The carapace lengths, dry weights, carbon content and nitrogen content of decapod larvae sorted from fresh plankton samples were measured. Regressions for the relationships between dry weight and carapace length were determined for each infraorder and for lower taxa. Regressions between carbon content, nitrogen content and C:N ratio and dry weight were calculated for the different taxa and were compared with published data on larvae reared in the laboratory.Decapod larvae often comprise a significant component of the zooplankton of estuaries and inshore waters (Lindley et al., 1994). Lindley (1988) has presented data on the relationship between dry weight and carapace length for brachyuran larvae from the plankton. Similar data for other groups of decapods and additional data and analyses for brachyurans are presented here with data on carbon and nitrogen content. Anger & Harms (1990) described the relationships between dry weight; carbon and nitrogen content for decapod larvae reared under controlled conditions in the laboratory. The results of measurements on specimens caught in the plankton in naturally varying conditions provide a comparison with laboratory reared larvae. Harms et al. (1994) compared dry weights and biochemical data for Carcinus maenas (Brachyura) larvae reared in the laboratory with specimens from the plankton off Helgoland. Dry weights of the last two zoea stages and the megalopa larvae from the plankton were higher. The percentage carbon, nitrogen and lipid content were higher in laboratory raised larvae which were fed on Artemia nauplii than in field specimens or in laboratory reared specimens fed on phytoplankton or starved.


Author(s):  
A. Wardah ◽  
Tiurma Wiliana Susanti Panjaitan

The aim of this research is to evaluate the effect of distiller dried grain (DDG) of rice husk in quail feed which effectively reduces important chemical elements in feces. The results showed that administration of DDG influenced the absorption of nutrients carbon, nitrogen, phosphorus and calsium in the quail intestine. Substitution of 10% DDG proportion in quail formulation not significantly (P>0.05) effect on carbon content in feces. Carbon content  infeces of quail at proportion of 20% DDG were significantly (P<0.01) higher than 10%. Nitrogen content in feces of quail at proportion of 20% DDG significant (P<0.05) higher than  both 10 and 0%.Futhermore nitrogen content in quail feces at 10% DDG significant (P<0.05) higher than 0%. Phosphorus content in feces quails at proportion of 10 and 20% DDG significantly (P<0.05) lower than 0%. Calcium content in quail feces at 10% and 0% not significant (P>0.05) but both were significantly (P<0.05) lower than 20%. The results of this study can be concluded that the substitution of 10% DDG of rice husk in quail feed formulations can increase absorption of phosphorus but decreases the absorption of carbon, nitrogen and calcium   Keyword: chemical elements, distillater dried grain, feces, quail


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