scholarly journals Fitness Costs Associated to an Ile2041Asn Mutation in the Geophyte Sorghum halepense Resistant to ACCase-Inhibiting Herbicides

2021 ◽  
Vol 3 ◽  
Author(s):  
Silvia Panozzo ◽  
Maurizio Sattin
Keyword(s):  
Resistance Management ◽  
Dry Weight ◽  
Sorghum Halepense ◽  
Soil Tillage ◽  
Allometric Relationships ◽  
Fitness Costs ◽  
Site Mutation ◽  
Plant Parts ◽  
Continuous Application ◽  
Sequence Method

Sorghum halepense (L.) Pers. is a troublesome weed of maize which reproduces through seeds and rhizomes. Resistance to ACCase-inhibiting herbicides due to a target-site mutation Ile-Asn in position 2041 of the ACCase gene was confirmed in several populations in Italy. The presence of fitness costs related to the allelic variant Ile2041Asn has never been investigated in ACCase-resistant S. halepense. Three growth analyses pot experiments were performed starting from rhizome buds (Exp1 and Exp3) or seed (Exp2). Plant development was monitored throughout the life cycle through destructive samplings. The mutation responsible for resistance to ACCase inhibitors was detected in all plants included in the experiments using a Cleaved Amplified Polymorphic Sequence method. Classical growth analysis was performed for the multiple sampling experiments (Exp1 and Exp2) and allometric relationships were calculated for the different dry weight plant parts in all experiments. Allometric relationships showed that susceptible (S) and ACCase resistant (R) biotypes allocated biomass differently in the reproductive structures: S populations allocated on average 30% more biomass in the panicles, whereas R populations allocated 12% more biomass to rhizomes than S populations. This was more evident when the experiments started from rhizomes buds. Reproductive allocation and reproductive effort were higher in S biotypes and R biotypes, respectively. The higher production of rhizomes and the lower production of seeds of the R biotype can significantly impact the evolution of herbicide resistance under continuous application of herbicides with the same mode of action. A medium-long term resistance management strategy which implements appropriate soil tillage and crop rotation taking into account the different reproductive attitude of biotypes S and R should be devised.

scholarly journals Fitness of Herbicide-Resistant Weeds: Current Knowledge and Implications for Management

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 469 ◽  
Author(s):  
Vila-Aiub
Keyword(s):  
Life History ◽  
Herbicide Resistance ◽  
Management Practices ◽  
Current Knowledge ◽  
Resistance Management ◽  
Fitness Cost ◽  
Plant Fitness ◽  
Resistance Mutations ◽  
Fitness Costs ◽  
Wide Range

Herbicide resistance is the ultimate evidence of the extraordinary capacity of weeds to evolve under stressful conditions. Despite the extraordinary plant fitness advantage endowed by herbicide resistance mutations in agroecosystems under herbicide selection, resistance mutations are predicted to exhibit an adaptation cost (i.e., fitness cost), relative to the susceptible wild-type, in herbicide untreated conditions. Fitness costs associated with herbicide resistance mutations are not universal and their expression depends on the particular mutation, genetic background, dominance of the fitness cost, and environmental conditions. The detrimental effects of herbicide resistance mutations on plant fitness may arise as a direct impact on fitness-related traits and/or coevolution with changes in other life history traits that ultimately may lead to fitness costs under particular ecological conditions. This brings the idea that a “lower adaptive value” of herbicide resistance mutations represents an opportunity for the design of resistance management practices that could minimize the evolution of herbicide resistance. It is evident that the challenge for weed management practices aiming to control, minimize, or even reverse the frequency of resistance mutations in the agricultural landscape is to “create” those agroecological conditions that could expose, exploit, and exacerbate those life history and/or fitness traits affecting the evolution of herbicide resistance mutations. Ideally, resistance management should implement a wide range of cultural practices leading to environmentally mediated fitness costs associated with herbicide resistance mutations.

scholarly journals EFFECT OF MINERAL DEFICIENCY ON MORPHOLOGICAL AND PHYSIOLOGICAL PARAMETERS AND ON SHOOT AND ROOT MINERAL PARTITIONING IN THREE SUNFLOWER VARIETIES / EFECTO DE LA FALTA DE ELEMENTOS MINERALAS SOBRE LOS PARAMENTROS MORFOLOGICOS Y FISIOLOGICOS Y REPARTICION DE ELEMENTOS MINERALES DE LA PARTE SOBRE EL SUELO Y DE LA RAIZ EN TRES VARIEDADES / INFLUENCE DE LA CARENCE D’ÉLÉMENTS MINÉRAUX SUR LES PARAMÈTRES MORPHOLOGIQUES ET PHYSIOLOGIQUES ET SUR LA DISTRIBUTION DES ÉLÉMENTS MINÉRAUX ENTRE LA PARTIE AÉRIENNE ET LA RACINE POUR TROIS SORTES DE TOURNESOL

Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 135-148
Author(s):  
Mohammed El Midaoui ◽  
Ahmed Talouizte ◽  
Benbella Mohamed ◽  
Serieys Hervé ◽  
Ait Houssa Abdelhadi ◽  
...  
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Growth Parameters ◽  
Dry Weight ◽  
Mineral Deficiency ◽  
P Deficiency ◽  
Plant Parts ◽  
Shoot Dry Weight ◽  
K Deficiency ◽  
Matter Effect

SUMMARYAn experiment has been carried out in order to study the behaviour under mineral deficiency of three sunflower genotypes, a population variety (Oro 9) and two hybrids (Mirasol and Albena). Sunflower seedlings were submitted to five treatments: N deficiency (N0), P deficiency (P0), K deficiency (K0), N and K deficiency (N0K0) and a control. Plants were harvested when they reached 3-4 true pairs of leaves. Growth parameters measured (height, total leaf area, root length, root and shoot dry mater) were all significantly reduced by mineral deficiency. Leaf area was most reduced by N0 (-61%) and P0 (-56%). Total dry matter was most affected by N0 (-63%) and by N0K0 (-66%). Genotype comparisons showed that Oro 9 had the highest shoot dry matter while Albena had the lowest root dry matter. Effect of mineral deficiency on content and partitioning of N, P, K, Ca and Na was significant and varied according to treatments and among plant parts. Shoot dry weight was significantly correlated with root N content (r2=0.81) and root K content (r2=-0.61) for N0 and K0.

Assessing Soil and Plant Pollution by Abandoned Rural Waste Dumping Sites in Ningbo, China

2011 ◽  
Vol 138-139 ◽  
pp. 1149-1155 ◽  
Author(s):  
Yi Dong Guan ◽  
Ye Hong Du ◽  
Zhen Dong Li ◽  
An Cheng Luo
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Reference Value ◽  
Dry Weight ◽  
Rice Grain ◽  
Contamination Assessment ◽  
Plant Parts ◽  
Metal Contents ◽  
Plant Pollution

This paper reports the concentration of heavy metals (Cr, Cu, Zn, Cd and Pb) in the soils and rices surrounding the abandoned rural waste dumping sites in Ningbo. Igeo (geoaccumulation index) was calculated to assess the contamination degree of heavy metals in soils. The mean contents of Cr, Cu, Cd, Zn and Pb of soils were 33.3, 24.1, 1.5, 118.9 and 45.6 mg/(kg DW) (dry weight), respectively. All of them were much higher than that of the reference value (i.e. CK), but there were no coherent trend of the metal contents within 1-120m distance from the dumping site. Igeo of heavy metals reveals the order of Cd>Cu>Cr>Pb>Zn, and the contamination assessment of soils using Igeo indicate the moderate Cd pollution, while the soils were unpolluted-moderately overall by Cr, Cu, Zn as well as Pb. The heavy metal contents in root, stem & leaf and rice grains were all remarkable higher than that of the CK at 20-120 m distances, and the heavy metal contents in root were evidently much higher than other plant parts, while those in rice grain were lowest, indicating the great bioaccumulation trend of heavy metals. Although the metal contents in the rice grain were within the legislation limit, its bioaccumulation trend of heavy metals was remarkable, whose contents were 4.38-fold for Cr, 1.76-fold for Cu, 1.28-fold for Zn, 2.67-fold for Cd and 3.03-fold for Pb higher than that of reference value, respectively. Finally, we proposed a decentralized in-situ restoration approach for the dumping sites.

Characteristics of the canopy, root system and grain yield of a crop of Lupinus angustifolius cv. Unicrop

1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area ◽  
Time Course ◽  
Dry Weight ◽  
Grain Filling ◽  
Main Axis ◽  
Carbon Dioxide Exchange ◽  
Area Index ◽  
Plant Parts

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.

Prevention and Detection of Fungicide Resistance Development in Rhizoctonia zeae from Soybean and Corn in Nebraska

2021 ◽  
Author(s):  
Nikita Gambhir ◽  
Srikanth Kodati ◽  
Matthew Huff ◽  
Flávio Silva ◽  
Olutoyosi Ajayi-Oyetunde ◽  
...  
Keyword(s):  
Fungicide Resistance ◽  
Resistance Management ◽  
Dry Weight ◽  
Geographic Region ◽  
Population Characteristics ◽  
Current Status ◽  
In Planta ◽  
Resistance Development ◽  
Rhizoctonia Zeae

The goal of this research was to advance the foundational knowledge required to quantify and mitigate fungicide resistance in Rhizoctonia zeae, the seedling disease pathogen of soybean and corn. In vitro sensitivity to azoxystrobin, fludioxonil, sedaxane, and/or prothioconazole was determined for 91 R. zeae isolates obtained mostly from soybean and corn fields in Nebraska. Isolates were sensitive to fludioxonil, sedaxane, and prothioconazole (EC50 < 3 µg/ml) and had a positively skewed EC50 distribution. Isolates were not sensitive to azoxystrobin in vitro (EC50 > 100 µg/ml) or in planta. Application of azoxystrobin did not significantly decrease disease severity or improve total dry weight of the soybean plants (P > 0.05). The risk of resistance development in R. zeae was estimated by characterizing its population structure. Eighty-one R. zeae isolates were genotyped using six microsatellite markers. Results showed that the population has a mixed mode of reproduction and is structured according to geographic region, suggesting limited dispersal. These population characteristics suggest that R. zeae has an intermediate risk of resistance development. Overall, this research established the current status of fungicide sensitivity in R. zeae in Nebraska and estimated its risk of resistance development, which can inform fungicide resistance management for R. zeae.

Fitness costs associated with spinetoram resistance in Spodoptera frugiperda is driven by host plants

2021 ◽  
Author(s):  
Rubens Hideo Kanno ◽  
Aline Guidolin ◽  
Fernando Padovez ◽  
Juliana Rodrigues ◽  
Celso Omoto
Keyword(s):  
Insecticide Resistance ◽  
Spodoptera Frugiperda ◽  
Host Plants ◽  
Agricultural Landscape ◽  
Growth Parameters ◽  
Resistance Management ◽  
Population Increase ◽  
Relative Fitness ◽  
Fitness Costs ◽  
Cotton Plants

Insecticide resistance is usually associated with fitness costs. The magnitude of fitness costs is affected by environmental and ecological factors. Here, we explored how host plants could affect fitness costs associated with insecticide resistance. Initially, spinetoram-resistant (RR) and susceptible (SS) strains of Spodoptera frugiperda were selected using F2 screen from a population collected in Sao Desiderio, Bahia State, Brazil in 2018. Besides de RR and SS strains, fitness costs were also assessed for a heterozygous strain (RS). Life-history traits were evaluated to estimate population growth parameters of neonate larvae of each strain fed on corn, soybean and cotton plants. Compared to the SS strain, the relative fitness of the RR strain, based on intrinsic rate of population increase, was 1.06, 0.84 and 0.67 on plants of corn, soybean and cotton respectively. The relative fitness of the RS strain was similar to the SS strain regardless the host plant, suggesting a recessive fitness cost. No differences were found between the strains fed on corn plants. The larval development time was greater for RR strain fed on soybean and cotton plants compared to RS and SS strain. Low survival rate and fecundity of the RR strain were found when larvae fed on plants of soybean and cotton. The results of this study demonstrated that fitness costs of spinetoram resistance in S. frugiperda depend strongly on the host plants that S. frugiperda larvae fed on. Such information can be used to design resistance management strategies considering the host plants of the agricultural landscape. Keywords: fall armyworm; spinosyns; insect resistance management; relative fitness.

scholarly journals Production of cabbage grown in pots containing legumes' root and shoot

Revista CERES ◽  
2012 ◽  
Vol 59 (5) ◽  
pp. 689-694 ◽  
Author(s):  
Thiago de Oliveira Vargas ◽  
Ellen Rúbia Diniz ◽  
Ricardo Henrique Silva Santos ◽  
Alysson Roberto de Almeida ◽  
Segundo Urquiaga ◽  
...  
Keyword(s):  
Block Design ◽  
Mineral Fertilizer ◽  
Dry Weight ◽  
N Fertilization ◽  
Recommended Dose ◽  
Legume Species ◽  
Mineral Fertilization ◽  
Mineral N ◽  
Plant Parts ◽  
Whole Plant

Roots effect is not generally considered in studies assessing the performance of crops in response to green manuring. However, such effect can contribute to a better understanding of crop rotation. The aim of this study was to assess the effect of root and shoot of two legumes on the production of cabbage. The experiment was conducted in pots of 10 liters containing substrate of 2:1 soil/sand. The experiment was arranged in a factorial scheme (2x3 + 2) in a randomized block design with five replicates using two legume species (Crotalaria juncea L. and Canavalia ensiformis L), three plant parts (root, shoot, or whole plant), and two additional treatments (mineral fertilization with 100% and 50% of the recommended dose of N for growing cabbage). Pots with legume treatments received mineral fertilizer with 50% of the recommended dose of N for growing cabbage. The experimental plot consisted of a pot containing one plant of cabbage. Legumes were grown in pots and harvested at 78 days. The root biomass was determined in extra pots. Production was assessed using head fresh and dry weight. The application of the whole plant of both legume species reduced cabbage production. However, root or shoot of both legume species was equivalent to 50% of mineral N fertilization required for the cultivation of cabbage.

Nutritional and physiological responses of the dicotyledonous halophyte Sarcocornia fruticosa to salinity

2017 ◽  
Vol 65 (7) ◽  
pp. 573 ◽  
Author(s):  
Pedro García-Caparrós ◽  
Alfonso Llanderal ◽  
Maribela Pestana ◽  
Pedro José Correia ◽  
María Teresa Lao
Keyword(s):  
Dry Weight ◽  
Biofuel Production ◽  
Peat Moss ◽  
Organic Osmolytes ◽  
Salinity Treatment ◽  
Tissue Water ◽  
Plant Parts ◽  
Sphagnum Peat Moss ◽  
Net Uptake ◽  
Sarcocornia Fruticosa

Sarcocornia fruticosa (L.) A.J. Scott is a dicotyledonous halophyte that grows in areas with an arid climate such as the marshes of southern Spain. The species has potential uses for saline agriculture and biofuel production, but the effects of salt stress on its nutrition and physiology remain unclear. Plants of S. fruticosa were grown in pots with a mixture of sphagnum peat-moss and Perlite. In order to evaluate the effects of different levels of salinity, five treatments using different NaCl concentrations (10 (control), 60, 100, 200 and 300 mM NaCl) were applied over a period of 60 days. At the end of the experiment, the dry weight, the biomass allocation and the tissue water content were measured for each salinity treatment. The net uptake of various nutrients and their translocation rates were calculated for each salt treatment. Salt loss, shedding of plant parts and succulence in shoots were evaluated together with the K+/Na+ ratio, K-Na selectivity, concentrations of osmolytes and their estimated contributions to the osmotic potential. Our results showed that S. fruticosa can maintain its major physiological processes at 60 mM NaCl without significant dry weight reduction. Higher salinity resulted in negative values for net uptake and translocation rates from roots to shoots of N and P. As might be predicted from other dicotyledonous halophytes, S. fruticosa plants increased Cl– and Na+ uptake using both as osmotica instead of organic osmolytes. However, to survive salinity, this species has also evolved others mechanisms such as shedding old shoots, increased succulence in shoots at higher salt concentrations and the ability to maintain a lower K+/Na+ ratio and higher K-Na selectivity in all organs.

scholarly journals Genotypic Variationin Dry Weight and Nitrogen Concentration of Wheat Plant Parts; Relations to Grain Yield and Grain Protein Concentration

2012 ◽  
Vol 4 (11) ◽  
Author(s):  
Ali Hafeez Malik ◽  
Allan Andersson ◽  
Ramune Kuktaite ◽  
Muhammad Yaqub Mujahid ◽  
Bismillah Khan ◽  
...  
Keyword(s):  
Grain Yield ◽  
Protein Concentration ◽  
Nitrogen Concentration ◽  
Wheat Plant ◽  
Dry Weight ◽  
Grain Protein ◽  
Grain Protein Concentration ◽  
Plant Parts

scholarly journals Cadmium affects the regeneration of the leafy vegetable Talinum portulacifolium stem cuttings in nutrient solution

2020 ◽  
pp. 147-159
Author(s):  
Thangavelu Muthukumar ◽  
Selvam Dinesh-Babu
Keyword(s):  
Morphological Characteristics ◽  
Dry Weight ◽  
Hydroponic Culture ◽  
Leafy Vegetable ◽  
Regeneration Ability ◽  
Tolerance Index ◽  
Stem Cuttings ◽  
Polluted Soils ◽  
Cd Accumulation ◽  
Plant Parts

Investigamos el efecto de varias concentraciones (0,0-5,0 ppm) de cadmio (Cd) en la capacidad de regeneración; las características morfológicas y la acumulación de Cd en los esquejes de tallo de la verdura de hoja Talinum portulacifolium cultivada en cultivo hidropónico. El Cd retrasó la brotación de los esquejes en un 7%, la callosidad en un 8% y el enraizamiento en un 38%. Las diferentes concentraciones de Cd afectaron significativamente a los pesos fresco y seco de las partes de la planta, excepto las raíces. La acumulación de Cd fue mayor en los tallos que en las hojas (2,22 vs 0,57 ppm). El índice de tolerancia calculado osciló entre el 59% y el 88%. Basándose en las observaciones, se concluyó que el Cd interfiere con la regeneración de los esquejes de tallo de T. portulacifolium e implica preocupación sobre el consumo y el uso terapéutico de esta hortaliza de hoja que crece en suelos contaminados. We investigated the effect of various concentrations (0.0-5.0 ppm) of cadmium (Cd) on the regeneration ability; morphological characteristics and Cd accumulation in the leafy vegetable Talinum portulacifolium stem cuttings grown in hydroponic culture. Cd delayed sprouting of stem cuttings by 7%, callusing by 8% and rooting by 38%. Different Cd concentrations significantly affected fresh and dry weight of plant parts except roots. Accumulation of Cd was more in the stems than in leaves (2.22 vs 0.57 ppm). The calculated tolerance index ranged from 59% to 88%. Based on the observations it was concluded that Cd interferes with the regeneration of T. portulacifolium stem cuttings and imply concerns on the consumption and therapeutic use of this leafy vegetable growing on polluted soils.

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