Estimating numbers.

2021 ◽  
pp. 42-59
Author(s):  
Johannes Hallmann ◽  
Matthias Daub ◽  
Wim Wesemael
Keyword(s):  
Plant Tissue ◽  
Field Soil ◽  
Egg Masses ◽  
Gall Index

Abstract Estimating nematode numbers is required to quantify the presence of certain nematode taxa in plant tissue, field soil or any other substrates. This chapter describes the enumeration of nematodes within plant tissue (e.g. roots, stems, leaves, seeds) and in liquids. It also deals with estimating numbers of cysts; eggs and juveniles isolated from cysts; gall index; and egg masses.

Estimating numbers.

2021 ◽  
pp. 42-59
Author(s):  
Johannes Hallmann ◽  
Matthias Daub ◽  
Wim Wesemael
Keyword(s):  
Plant Tissue ◽  
Field Soil ◽  
Egg Masses ◽  
Gall Index

Abstract Estimating nematode numbers is required to quantify the presence of certain nematode taxa in plant tissue, field soil or any other substrates. This chapter describes the enumeration of nematodes within plant tissue (e.g. roots, stems, leaves, seeds) and in liquids. It also deals with estimating numbers of cysts; eggs and juveniles isolated from cysts; gall index; and egg masses.

Flaming to Reduce Inocula of the Boxwood Blight Pathogen, Cylindrocladium pseudonaviculatum, in Field Soil

2012 ◽  
Vol 13 (1) ◽  
pp. 33 ◽  
Author(s):  
Norman L. Dart ◽  
Sarah M. Arrington ◽  
Sarah M. Weeda
Keyword(s):  
Significant Role ◽  
Plant Tissue ◽  
Field Soil ◽  
Infested Plant ◽  
Infested Field

Infested plant tissue can play a significant role in the epidemiology of boxwood blight in ornamental nursery systems. In an effort to reduce inoculum levels in an infested field in Carroll Co., Virginia, symptomatic plants were removed, collected into a pile, and destroyed by burning using a propane push flamer. The authors investigated whether soil flaming would be effective to reduce viable inocula of C. pseudonaviculatum in the upper layer of soil. Accepted for publication 4 October 2012. Published 26 October 2012.

scholarly journals F4 families of crispleaf lettuce with tolerance to early bolting and homozygous for resistance to Meloidogyne incognita race 1

2009 ◽  
Vol 27 (3) ◽  
pp. 335-339
Author(s):  
José Luiz S de Carvalho Filho ◽  
Luiz Antonio A Gomes ◽  
Felipe A Biguzzi ◽  
Wilson Roberto Maluf ◽  
Sindynara Ferreira
Keyword(s):  
Root System ◽  
Meloidogyne Incognita ◽  
Leaf Blade ◽  
Fresh Weight ◽  
Root Knot Nematode ◽  
Egg Masses ◽  
Grand Rapids ◽  
Race 1 ◽  
Gall Index

The objective of this study was to evaluate yield, commercial characteristics, tolerance to early bolting and resistance to the root-knot nematode Meloidogyne incognita race 1 in 25 F4 families of crispleaf lettuce, obtained out of crosses between cultivars Grand Rapids, Regina 71, and Verônica. In the first experiment, we evaluate leaf blade and borders characteristics, aboveground fresh weight, and number of days from sowing to the anthesis of first flower (tolerance to early bolting). In the second experiment, we evaluated the resistance to Meloidogyne incognita race 1 via gall index and number of galls and egg masses per root system. Five families had scores for leaf blade and borders similar to cultivars Verônica and Grand Rapids. Furthermore, 84% of the families were as tolerant to early bolting as cultivar Veronica, while 92% of the families were homozygous for resistance to Meloidogyne incognita race 1.

scholarly journals Evaluation of Efficacy of Paecilomyces Lilacinus as Biological Control Agent of Meloidogyne Incognita Attacking Tomato

2009 ◽  
Vol 49 (4) ◽  
pp. 337-340 ◽  
Author(s):  
Elvira Oclarit ◽  
Christian Cumagun
Keyword(s):  
Biological Control ◽  
Meloidogyne Incognita ◽  
Biological Control Agent ◽  
Control Agent ◽  
Paecilomyces Lilacinus ◽  
Egg Mass ◽  
Root Weight ◽  
Egg Masses ◽  
Root Sample ◽  
Gall Index

Evaluation of Efficacy of Paecilomyces Lilacinus as Biological Control Agent of Meloidogyne Incognita Attacking Tomato The efficacy of Paecilomyces lilacinus strain UP1 as biological control agent of Meloidogyne incognita attacking tomato was evaluated under screenhouse condition pot experiments. P. lilacinus was formulated on rice substrate in powder form. Root weight, gall index rating, number of galls, egg masses and nematodes per one gram root sample were determined and per cent reduction in gall number was computed. Root weight and gall index ratings were significantly higher in untreated plants than those with P. lilacinus and with the commercial fungicide Nemacur. Number of galls, nematodes and egg masses per one gram root sample were significantly reduced by the application of P. lilacinus at all levels and this was comparable with Nemacur. However, egg mass count in plants treated with the lowest concentration of the biocontrol agent was not significantly different from the uninoculated control. Per cent reduction in gall number was the highest at treatment with 7.92 × 106 spores per ml of P. lilacinus.

Transformation of Isopropalin in Soil and Plants

Weed Science ◽  
1975 ◽  
Vol 23 (3) ◽  
pp. 165-171 ◽  
Author(s):  
Tomasz Golab ◽  
W. A. Althaus
Keyword(s):  
Plant Tissue ◽  
Transformation Products ◽  
Plant Tissues ◽  
Field Soil

Field soil studies with 14C-isopropalin (2,6-dinitro-N,N-dipropylcumidine) have demonstrated its biodegradability. None of the recognizable transformation products in soil accumulated beyond 4% of the amount of applied herbicide. After 15 months, approximately 25% of the applied isopropalin remained in soil, and less than 10% was observed after 28 months. Only negligible amounts of radioactivity were detected in crops grown in soil treated with the herbicide. Isopropalin and its recognizable transformation products were not detected in any of the plant tissues examined. Fractionation techniques indicated that the radioactivity was randomly distributed throughout the plant tissue.

scholarly journals ACTIVITY OF RUTA GRAVEOLENS L. AGAINST ROOT-KNOT NEMATODES (MELOIDOGYNE spp.)

2020 ◽  
pp. 525-534
Author(s):  
Sasanelli ◽  
Toderas ◽  
Iurcu-Straistaru ◽  
D’Addabbo ◽  
Migunova ◽  
...  
Keyword(s):  
Population Density ◽  
Soil Nematode ◽  
Distilled Water ◽  
Ruta Graveolens ◽  
Egg Masses ◽  
Vitro Experiment ◽  
In Vitro Experiment ◽  
Nematode Population Density ◽  
Gall Index

Two in vitro experiments and two open field trials were carried out to investigate the nematicidal effect of Ruta graveolens on the root-knot nematode Meloidogyne incognita. In the first in vitro experiment the nematode egg masses were immersed for 3 weeks in aqueous leaf extract of rue plants and then subjected to an hatching test in distilled water for five more weeks. In the other in vitro experiment M. incognita egg masses were exposed to the rue extract for 4, 8 and 16 hours and then incubated in distilled water for 8 weeks. Distilled water and a 5 μg/mL an aqueous solution of Fenamiphos or only distilled water were used as controls in the first and second in vitro experiment, respectively. Both hatching tests were carried out in a growth cabinet at 25±2 0C, providing four replicates for each treatment. In the first experiment the hatching from the egg masses treated with rue extracts and Fenamiphos solution resulted significantly lower than that in the untreated control. In the second in vitro experiment, a 8-hour immersion of the egg masses in the rue extract resulted in a final hatch significantly lower than that in distilled water. The nematicidal effect of R. graveolens green manure was investigated in open field condition on tomato and tobacco. Plots amended with rue plant biomass were compared with untreated and Fenamiphos treated plots (3 t/ha). Four replications were provided for each treatment. Crop yield, root gall index and soil nematode population density were recorded at the end of each crop cycle. Soil incorporation with R. graveolens plant materials significantly increased both tomato and tobacco yield and reduced root gall index and soil nematode population density in comparison to the untreated controls. These experiments demonstrated a high suitability of R. graveolens for the development of new sustainable nematicidal products.

Freeze-fracture, freeze-etch complementary pairs of virus-infected cells reveal value of etching even when relatively high concentrations of cryoprotectants are used

1978 ◽  
Vol 36 (2) ◽  
pp. 136-137
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Plant Tissue ◽  
Phosphate Buffer ◽  
Infected Plant ◽  
Freeze Fracture ◽  
Distilled Water ◽  
Virus Infected Plant ◽  
Infected Cells ◽  
High Concentrations

It has been assumed by many involved in freeze-etch or freeze-fracture studies that it would be useless to etch specimens which were cryoprotected by more than 15% glycerol. We presumed that the amount of cryoprotective material exposed at the surface would serve as a contaminating layer and prevent the visualization of fine details. Recent unexpected freeze-etch results indicated that it would be useful to compare complementary replicas in which one-half of the frozen-fractured specimen would be shadowed and replicated immediately after fracturing whereas the complement would be etched at -98°C for 1 to 10 minutes before being shadowed and replicated.Standard complementary replica holders (Steere, 1973) with hinges removed were used for this study. Specimens consisting of unfixed virus-infected plant tissue infiltrated with 0.05 M phosphate buffer or distilled water were used without cryoprotectant. Some were permitted to settle through gradients to the desired concentrations of different cryoprotectants.

Freeze-Fracture Studies of Membranes in Developing Sieve Elements in a Plant Tissue Culture

1980 ◽  
Vol 38 ◽  
pp. 636-637
Author(s):  
R. D. Sjolund ◽  
C. Y. Shih
Keyword(s):  
Plant Tissue ◽  
Cultured Cells ◽  
Freeze Fracture ◽  
Tissue Cultures ◽  
Sieve Elements ◽  
Intact Plants ◽  
Plant Tissue Cultures ◽  
Whole Plants ◽  
Energy Dependent ◽  
Similar Elements

The differentiation of phloem in plant tissue cultures offers a unique opportunity to study the development and structure of sieve elements in a manner that avoids the injury responses associated with the processing of similar elements in intact plants. Short segments of sieve elements formed in tissue cultures can be fixed intact while the longer strands occuring in whole plants must be cut into shorter lengths before processing. While iyuch controversy surrounds the question of phloem function in tissue cultures , sieve elements formed in these cultured cells are structurally similar to those of Intact plants. We are particullarly Interested In the structure of the plasma membrane and the peripheral ER in these cells because of their possible role in the energy-dependent active transport of sucrose into the sieve elements.

Development of Plant Tissue Culture Profile of Dioscorea deltoidea

Planta Medica ◽  
2013 ◽  
Vol 79 (05) ◽  
Author(s):  
M Mujeeb ◽  
M Amir ◽  
AS Nadeem ◽  
M Aqil ◽  
AK Najmi ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Plant Tissue Culture ◽  
Plant Tissue ◽  
Dioscorea Deltoidea

Natural parasitism of eggs of yellow stem borer, Scirpophaga incertulas Walker (Lepidoptera: Crambidae) in rice ecosystem at Tiruchirappalli, Tamil Nadu

ENTOMON ◽  
2020 ◽  
Vol 45 (3) ◽  
pp. 181-188
Author(s):  
T. Sharmitha ◽  
C. Gailce Leo Justin ◽  
S. Sheeba Joyce Roseleen ◽  
P. Yasodha
Keyword(s):  
Field Study ◽  
Tamil Nadu ◽  
Host Density ◽  
Stem Borer ◽  
Scirpophaga Incertulas ◽  
Egg Masses ◽  
Yellow Stem Borer ◽  
Rice Ecosystem ◽  
Natural Parasitism

Three species of parasitoids viz., Telenomus dignus Gahan, Trichogramma japonicum, Ishii and Tetrastichus schoenobii Ferriere were recorded from the egg masses of rice yellow stem borer, Scirpophaga incertulas (Walker) in a field study. The extent of parasitism was high during Rabi (43.33 – 93.33 %) and low during Kharif (0 - 40.00 %). Parasitism by T. dignus was maximum in October (50.00 %), T. japonicum, in November (23.08 %) and T. schoenobii in February (55.55 %). dignus and T. schoenobii in combination parasitized maximum number of egg masses (41.82 %). Multiple parasitism by the three species was high in December (8.33 %) and January (7.14%). Parasitic potential was maximum, when T. schoenobii alone parasitised the egg masses followed by T. dignus and T. schoenobii in combination. Host density in the field influenced the extent of parasitism.

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