scholarly journals Respuesta del perejil crespo a diferentes densidades de población de Meloidogyne arenaria

2021 ◽  
Vol 23 (1) ◽  
pp. 55-60
Author(s):  
Leslie Sharon Lozada-Villanueva ◽  
◽  
Teodocia Gloria Casa-Ruiz ◽  
Cristiano Bellé ◽  
◽  
...  
Keyword(s):  
Population Density ◽  
Initial Population ◽  
Fresh Weight ◽  
Root Knot Nematode ◽  
Initial Population Density ◽  
Second Stage ◽  
Leaf Weight ◽  
Gall Index ◽  
Reproduction Factor ◽  
Curly Leaf

The effect of initial population density (Pi) of the peanut root-knot nematode, Melodoigyne arenaria, on curly leaf parsley growth was assessed in this study. The population densities of M. arenaria ranged from 0 to 64 eggs + second-stage juveniles (J2)/cm3 soil in sterile sandbags. The root gall index (RGI), reproduction factor (RF), fresh leaf weight (FLW), dry leaf weight (DLW), root fresh weight (RFW), root length (RL), leaf height (LH), and chlorophyll index (SPAD) were determined at 90 days after inoculation. FLW, DLW, RFW, LH, and SPAD data were fitted to the Seinhorst equation, y = m + (1 - m) zPi-T, to determine the tolerance limit T = 0.25 eggs +J2/cm3 soil for FLW, DLW, RFW, and LH, with relative means (m) of 0.52, 0.24, 0.22, and 0.4 respectively; conversely, the T value for SPAD was 0.125 eggs + J2/cm3 soil and with a m of 0.26. All biometric variables decreased with an increase in the initial population density (Pi). Nevertheless, the highest RF of M. arenaria in parsley was 78.92 for a Pi = 8 eggs + J2/cm3 soil, with an RGI value of 5 from Pi = 1 eggs + J2/cm3. Curly leaf parsley growth decreased with an increase in Pi of M. arenaria.

scholarly journals REACTION OF PSIDIUM SPP. ACCESSIONS TO DIFFERENT LEVELS OF INOCULATION WITH MELOIDOGYNE ENTEROLOBII

2019 ◽  
Vol 32 (2) ◽  
pp. 419-428
Author(s):  
PATRÍCIA GOMES DE OLIVEIRA ◽  
MANOEL ABILIO DE QUEIRÓZ ◽  
JOSÉ MAURO DA CUNHA E CASTRO ◽  
JULIANA MARTINS RIBEIRO ◽  
RONALDO SIMÃO DE OLIVEIRA ◽  
...  
Keyword(s):  
Yield Loss ◽  
State University ◽  
Fresh Weight ◽  
Root Knot Nematode ◽  
Second Stage ◽  
Meloidogyne Enterolobii ◽  
Positive Results ◽  
Different Levels ◽  
Reproduction Factor ◽  
Main Factor

ABSTRACT Meloidogyne enterolobii associated with Fusarium solani causes the guava decay, which is the main factor of yield loss in guava crops and limits guava production in Brazil. Therefore, searching for guava genotypes (Psidium spp.) with resistance to M. enterolobii is important to control this root-knot nematode. The objective of the present work was to evaluate the reaction of Psidium spp. accessions from the Germplasm Bank of the Bahia State University (UNEB) to different levels of inoculation with M. enterolobii. Guava seedlings were inoculated with 600, 1,600, and 2,000 eggs + J2 second stage juveniles of M. enterolobii and the root fresh weight, total number of eggs (TNE), and reproduction factor (RF) were evaluated. The results were subjected to ANOVA and means were clustered using the Scott-Knott test at 5% probability. The diversity of accessions was estimated using the Tocher's clustering and UPGMA methods. The nematode RF reduced in some accessions with increasing inoculation levels of the nematode. However, the RF increased in some accessions with high levels of inoculation. Plants of the Y50 accession were immune or resistant to M. enterolobii, indicating variability of reaction of plants to the nematode within the Psidium genus. The resistance of Psidium accessions to M. enterolobii needs to be measured with different inoculation levels to verify the existence of false-positive results, since the evaluated accessions, including the Paluma cultivar, presented distinct reactions regarding RF in the three levels of inoculation used.

Pathogenicity and Host–Parasite Relationships of Meloidogyne arenaria in Sweet Basil

Plant Disease ◽  
2008 ◽  
Vol 92 (9) ◽  
pp. 1329-1335 ◽  
Author(s):  
N. Vovlas ◽  
A. Troccoli ◽  
A. Minuto ◽  
C. Bruzzone ◽  
N. Sasanelli ◽  
...  
Keyword(s):  
Population Density ◽  
Plant Height ◽  
Initial Population ◽  
Meloidogyne Arenaria ◽  
Fresh Weight ◽  
Nematode Reproduction ◽  
Initial Population Density ◽  
Sweet Basil ◽  
Vascular Elements ◽  
Race 2

Stunted growth of sweet basil (cv. Genovese) associated with large patches and severe soil infestations by the root-knot nematode Meloidogyne arenaria race 2 were observed in open fields at the end of the crop-growing season in Albenga, province of Savona, Northern Italy by early September 2007. Observed morphological traits of nematode life stages and results of analysis of isozyme electrophoretic patterns and differential host tests were used for nematode species and race identification. Nematode-induced mature galls (either in naturally infected plants or in artificially inoculated root tissues) were spherical or ellipsoidal and confluent along the root axis, containing usually several females, males, and egg-masses with eggs. Feeding sites were characterized by the development of giant cells that contained several hypertrophied nuclei and nucleoli. Giant cell cytoplasm was aggregated along the thickened cell walls. Vascular elements within galls appeared disorganized and disrupted. Due to the heavy damage observed, the relationships between the initial population density and growth of basil plants was also tested in a greenhouse experiment in which inoculum levels varied from 0 to 512 eggs and juveniles/cm3 of soil. Height and top fresh weight data of the inoculated and control plants was fitted to Seinhorst's model. Tolerance limits with respect to plant height and fresh top weight of basil cv. Genovese plants to M. arenaria race 2 were estimated as 0.15 eggs and juveniles/cm3 of soil. The minimum relative values (m) for plant height and top fresh weight were 0.39 and 0.19 at initial nematode population density (Pi) ≥16 eggs and juveniles/cm3 of soil, respectively. The maximum nematode reproduction rate (Pf/Pi) was 448.7 times at an initial population density of 4 eggs and second-stage juveniles/cm3 of soil.

scholarly journals Reaction of potential guava rootstocks to Meloidogyne enterolobii

Revista CERES ◽  
2018 ◽  
Vol 65 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Fernando Marcelo Chiamolera ◽  
Antonio Baldo Geraldo Martins ◽  
Pedro Luiz Martins Soares ◽  
Tatiana Pagan Loeiro da Cunha-Chiamolera
Keyword(s):  
Root System ◽  
Fusarium Solani ◽  
Root Rot ◽  
System Development ◽  
Control Treatment ◽  
Root Knot Nematode ◽  
Second Stage ◽  
Root System Development ◽  
Meloidogyne Enterolobii ◽  
Reproduction Factor

ABSTRACT Root-knot nematode Meloidogyne enterolobii is the main phytosanitary problem of guava cultivation in Brazil. Among the strategies to manage the problem, the best prospects are in identifying or developing cultivars or rootstocks that are resistant to this nematode. To identify plants with potential as rootstocks for guava, the reaction of araçá (wild guava) to M. enterolobii was assessed in a greenhouse experiment. Seven araçá species were evaluated (Eugenia stipitata, Psidium acutangulum, P. cattleyanum ‘yellow’, P. friedrichsthalianum, P. guajava var. minor, P. guineense, and Psidium sp.). The plants were inoculated with a suspension of 3,000 eggs of M. enterolobii, using eggplant as control treatment. The parameters fresh root mass, number of eggs and second stage juveniles (J2) per root system, the reproduction factor (RF = Pf/Pi), and araçá reaction were determined during the experiment. RF of the araçá species E. stipitata, P. cattleyanum ‘yellow’, and P. friedrichsthalianum was less than one (RP < 1), therefore resistant to M. enterolobii. The araçá trees had good root system development and the susceptible plants showed many root galls, high number of eggs and J2, and Fusarium solani and Rhizoctonia solani root rot. The araçá species, P. cattleyanum ‘yellow’, P. friedrichsthalianum, and E. stipitata are resistant to M. enterolobii and can be tested as potential guava rootstocks.

scholarly journals Do the stage of plant and initial population of root knot nematode influence on sweet pepper development?

O Biológico ◽  
2020 ◽  
Vol 82 (1) ◽  
pp. 1-10
Author(s):  
Samara A. de Oliveira ◽  
Juliana M. O Rosa ◽  
Juliana Eulálio ◽  
Claudio Marcelo G. de Oliveira
Keyword(s):  
Sweet Pepper ◽  
Initial Population ◽  
Root Knot Nematode ◽  
One Pot ◽  
Leaf Pair ◽  
Final Population ◽  
Randomized Design ◽  
Meloidogyne Enterolobii ◽  
Shoot Weight ◽  
Reproduction Factor

The aim of this study was to investigate the response of three different stages (one, three and five leaf pairs) of sweet pepper (Capsicum annuum cv. Orazio) seedlings to five inoculation levels of Meloidogyne enterolobii (zero (control), 300, 1000, 3000 and 10000) under greenhouse conditions. Each plant was cultivated in one pot filled with 3.8 L of substrate. The test was a completely randomized design with four replications. The plants were assessed 60 days after inoculation, plant shoot weight, final population of nematodes, and reproduction factor were measured. The results were fitted to Seinhorst model: Y = m + (1-m). ZPi –T. The results showed a tolerance limit (T) of 2,500 nematodes for plants with one and three leaf pair, and 8,500 nematodes for the five-leaf pair plant.

scholarly journals A theoretical framework for multi-species range expansion in spatially heterogeneous landscapes

2021 ◽  
Author(s):  
Lukas Eigentler ◽  
Nicola R Stanley-Wall ◽  
Fordyce A Davidson
Keyword(s):  
Population Density ◽  
Range Expansion ◽  
Theoretical Framework ◽  
Dominant Mode ◽  
Bacterial Biofilm ◽  
Time Interval ◽  
Initial Population ◽  
Initial Population Density ◽  
Competitive Outcome ◽  
The Impact

Range expansion is the spatial spread of a population into previously unoccupied regions. Understanding range expansion is important for the study and successful manipulation and management of ecosystems, with applications ranging from controlling bacterial biofilm formation in industrial and medical environments to large scale conservation programmes for species undergoing climate-change induced habitat disruption. During range expansion, species typically encounter competitors. Moreover, the environment into which expansion takes place is almost always heterogeneous when considered at the scale of the individual. Despite the ubiquitous nature of these features, the impact of competition and spatial landscape heterogeneities on range expansion remains understudied. In this paper we present a theoretical framework comprising two competing generic species undergoing range expansion and use it to investigate the impact of spatial landscape heterogeneities on range expansion with a particular focus on its effect on competition dynamics. We reveal that the area covered by range expansion during a fixed time interval is highly variable due to the fixed landscape heterogeneities. Moreover, we report significant variability in competitive outcome (relative abundance of a focal species) but determine that this is induced by low initial population densities, independent of landscape heterogeneities. We further show that both area covered by range expansion and competitive outcome can be accurately predicted by a Voronoi tessellation with respect to an appropriate metric, which only requires information on the spatial landscape and the response of each species to that landscape. Finally, we reveal that if species interact antagonistically during range expansion, the dominant mode of competition depends on the initial population density. Antagonistic actions determine competitive outcome if the initial population density is high, but competition for space is the dominant mode of competition if the initial population density is low.

scholarly journals Reproduction of Meloidogyne enterolobii in lettuce cultivars of the American group

2015 ◽  
Vol 33 (2) ◽  
pp. 147-150
Author(s):  
Érika CSS Correia ◽  
Norberto Silva ◽  
Marylia GS Costa ◽  
Silvia RS Wilcken
Keyword(s):  
Reproductive Potential ◽  
Egg Mass ◽  
Root Knot Nematodes ◽  
Second Stage ◽  
American Group ◽  
Meloidogyne Enterolobii ◽  
Meloidogyne Spp ◽  
Gall Index ◽  
Summer Time ◽  
Reproduction Factor

Lettuce is the main vegetable cultivated in Brazil, in volume and in marketed value. There are ranges of diseases which may affect lettuce crops, including those caused by root-knot nematodes (Meloidogyne spp.). We evaluated the reproductive potential of Meloidogyne enterolobii in 22 lettuce cultivars. The plants were inoculated with 5,000 eggs and eventuals second stage juveniles of nematode per pot, two days after the transplanting. 'Rutgers' tomato was used as standard for inoculum viability of M. enterolobii. We evaluated, 60 days after inoculation, the gall index, egg mass index and reproduction factor (RF). The 'Ithaca', 'Raider Plus', 'RS-1397', 'L-104', 'Challenge', 'IP-11', 'Classic', 'Salinas 88', 'Vanguard 75', 'Calona' and 'Desert Queen' were resistant to M. enterolobii with RF varying from 0.22 to 0.9, and the cultivars Lady Winterset, Robinson, Sonoma, Raider, Lucy Brown, Bnondaga, Summer Time, Taina, Sundevil and L-109 were susceptible to this nematode, with RF ranging from 1.06 to 5.73.

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