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Nematoda. ISSN 2358-436X. Copyright © 2014. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

1http://dx.doi.org/10.4322/nematoda.03015 Nematoda, 2015;2: e032015

Resistance of Meloidogyne javanica in soybean genotypesJuliana Souza da Silva Bruinsmaa* and Zaida Inês Antoniollib

a Cooperativa Central Gaúcha Ltda., Unidade Tecnologia (CCGL TEC), Cruz Alta (RS) Brazilb Departamento de Solos, Universidade Federal de Santa Maria (UFSM), Santa Maria (RS) Brazil*[email protected]

HIGHLIGHTS• Genotypes CEPsBt 09036 and CEPsBt 10129 are resistant against Meloidogyne javanica, in greenhouse.• Genotype CEPsRR 07224 was the only one classified as resistant, under field conditions.• Root-knot nematode gall index (GI) and reproduction factor (RF) is relevant to classify soybean genotypes.• In this experiment, the egg mass number (EMN) results had no relationship with the results obtained for the variables GI and

RF.

ABSTRACT: This work aimed to assess the resistance of soybean genotypes to Meloidogyne javanica under field and greenhouse conditions. Genotypes CEPsRR 07224, CEPsBt 09036 and CEPsBt 10129 had the lowest gall intensity values under field conditions. Only genotype CEPsRR 07224 classified as resistant and the others were classified as moderately resistant in field. Genotype CEPsBt 10129 had the lowest value for number of galls and gall index under greenhouse conditions, and did not differed statistically from the resistant standard BRS 256RR. All genotypes showed RF> 1, and genotypes CEPsBt 09033, CEPsBt 09036 and CEPsBt 10129 had the lowest number of eggs and reproduction factor. Nevertheless, when using gall index and reproduction factor as evaluation criteria, both CEPsBt 09036 and CEPsBt 10129 performed as tolerant in field and greenhouse conditions.

Keywords: Glycine max, gall nematode.

Cite as Bruinsma JSS, Antoniolli ZI. Resistance of Meloidogyne javanica in soybean genotypes. Nematoda. 2015;2:e032015. http://dx.doi.org/10.4322/nematoda.03015

Received: Mar. 15, 2015 Accepted: Apr. 16, 2015

INTRODUCTIONSoybean [Glycine max (L.) Merrill] is currently the most important oilseed crop cultivated in the

world, by both its economic and nutritional significance, and its production is still increasing. Brazil, with a cultivated area of 25.04 million hectares, is the second largest grain producer. In 2011/12 Brazil produced 66.38 million tons, which represents 26.5% of the world’s entire production[1].

There are several factors that limit soybean production, among these are biotic factors, such as pathogenic fungi, bacteria, viruses and nematodes. Plant-parasitic nematodes are known for causing great yield losses[2, 3]. In Brazil, nematodes that have great damaging potential for soybean are the cyst nematode, Heterodera glycines Ichinohe, root-knot nematodes, Meloidogyne spp. (Goeldi), reniform nematode, Rotylenchulus reniformis Lindolf & Oliveira, and the lesion nematode, Pratylenchus brachyurus (Godfrey)[4].

Nematodes of the genus Meloidogyne are widely spread in Brazilian territory, and may affect negatively the production and quality in infested areas. The polyphagia of Meloidogyne species, their physiological variability and their wide distribution throughout different producing regions are serious obstacles to successfully control this parasite, particularly the crop rotation[5]. The use of resistant soybean cultivars is the most efficient and adequate control measure used by farmers[6, 7].


Bruinsma & Antoniolli Resistance of Meloidogyne javanica in soybean genotypes

Specific soybean breeding programs have obtained many cultivars with resistance to different Meloidogyne species, and increasingly research has been carried out in order to select resistant soybean cultivars adapted to different regions in the country. Sometimes, however, the results turn out to be divergent, which is largely attributed to the lack of standardization in the methodology used to evaluate the resistance and the different evaluation criteria used[5, 7].

Therefore, the present study aimed to evaluate the response of 12 soybean genotypes to M. javanica in order to select resistant genotypes with reduced nematode multiplication in the field.

MATERIAL AND METHODSExperimental assays were performed under field conditions in a naturally infested producing area

in Julio de Castilhos, Rio Grande do Sul, Brazil (28° 04’ S, 53° 39’ W), and in a greenhouse at Central Cooperative Gaucha Ltda. - Unit Technology (CCGL TEC - FUNDACEP), in Cruz Alta, Rio Grande do Sul, Brazil (28° 36’ S, 53° 40’ W), during the 2011/12 harvest. Field tests were performed before, due to the availability of the area.

For the study, 12 soybean genotypes with unknown response to M. javanica were used (CEPsRR 07224, CEPsRR 08414, CEPsBt 09018, CEPsBt 09021, CEPsBt 09030, CEPsBt 09033, CEPsBt 09036, CEPsBt 09049, CEPsRR 09086, CEPsBt 10129, FUNDACEP 58RR, FUNDACEP 64RR), plus the resistant standard BRS 256RR[3], and the susceptible standard BRS 243RR[3].

Evaluation under field conditionsIn the producing area, the sowing was performed in two dates: October 27th, 2011 and November

29th, 2011, with a layout of 1.00 m × 0.50 m, in a completely randomized statistical design, with ten replicates, where each plant was considered a replicate.

Evaluations were accomplished when the plants were at the R7 stage, which occurred on February 23rd, 2012 for the 1st sowing date, 118 days after planting, and March 03rd, 2012 for the 2nd sowing date, 126 days after planting. For the assessment, the plants were removed from the soil by digging, and the root system of each plant was evaluated regarding to the intensity of galls, using a scale from 0 to 5 suggested by the National Protection Service Cultivar, MAPA[8], where 0 = immune; 1 = one or two galls, normal root system; 2 = few small galls and well developed root system; 3 = small galls and slightly damaged root system; 4 = many galls and damaged root system; and 5 = root system completely taken by galls. Each genotype reaction was based on the average grade obtained for the number of galls on 10 repetitions, considering the two sowing dates. Genotypes that received grades up to 2.0 were considered resistant (R), genotypes with grades 2.1 to 3.0 were considered moderately resistant (MR), and those with grades above 3.0 were considered susceptible (S).

Evaluation in greenhouseThe same soybean genotypes were sowed in 500 mL plastic pots containing sterile (oven sterilized

at 90 °C for 10 hours) sand and soil substrate at a ratio of 1:2. Planting was done on March 20th, 2012. The inoculum of M. javanica was obtained from soybean plants from Julio de Castilhos’ field area. The extraction of eggs and second stage juveniles (J2) of the nematode was performed according to the methodology proposed by Hussey & Barker[9], modified by Boneti & Ferraz[10]. Counting of eggs was carried out in Peters chamber and the suspension calibrated to 1000 eggs/mL. The inoculation was performed 10 days after germination; therefore, each seedling was inoculated with 4.000 eggs and J2. The statistical design was completely randomized with ten replicates per genotype; each pot containing a plant represented a replicate. The seedlings were kept in greenhouse during the experiment with average temperatures of 12.1 °C minimum, and maximum of 30.3 °C. Fifty-five days after inoculation (May 24th, 2012), the plants were brought to the plant pathology laboratory of CCGL TEC, and the plastic pots were carefully removed. Then the roots were separated from the shoots, washed and evaluated for gall index (GI) using the scale suggested by Taylor & Sasser[11] and egg masses counted by acid fuchsin staining[12]. Then, the extraction of eggs and J2 of M. javanica was accomplished by the methodology proposed by Hussey & Barker[9], modified by Boneti & Ferraz[10]. The counting of eggs was carried out in Peters chamber with the aid of a light microscope. The number of eggs + J2 was used to calculate the reproduction factor (RF) as in Oostenbrink[13]. In this experiment, the resistance of soybean genotypes to the nematode was evaluated according to the classification proposed by Canto-Sáenz[14].


Resistance of Meloidogyne javanica in soybean genotypesBruinsma & Antoniolli

Field and greenhouse data underwent analysis of variance (ANOVA). The discrimination between the treatment means (genotypes) for the variables gall intensity, number of galls, gall index, egg mass number, number of eggs and reproduction factor, was performed by the Scott-Knott test at 5% probability using the software SASM-Agri[15].

RESULTS AND DISCUSSION

Evaluation under field conditionsThe evaluations of root systems of soybean genotypes grown in soil infested with M. javanica,

resulted in gall intensity values ranging from 1.8 to 3.6 in the 1st planting date, and 0.8 to 3.3 in the 2nd planting date (Table 1).

For the classification of soybean genotypes reaction to M. javanica, the average value of gall intensity obtained over the two planting dates were calculated (Table 1). After analyzing each planting date separately, the first planting date showed the following genotypes as remarkable: CEPsRR 07224, CEPsBt 09030, CEPsBt 09036, CEPsBt 10129 and FUNDACEP 58RR, which shared a similar pattern of gall intensity resistance (Table 1). In the 2nd date it was possible to divide the genotypes in three groups: 1st genotypes CEPsRR 07224, CEPsBt 09018, CEPsBt 09030, CEPsBt 09036, CEPsBt 09049, CEPsRR 09086, CEPsBt 10129 and FUNDACEP 64RR forming an intermediate group between resistant and susceptible standards; 2nd genotypes CEPsRR 08414, CEPsBt 09021 and CEPsBt 09033 with similar performance to the standard susceptible BRS 243RR; and 3rd the FUNDACEP 58RR genotype with a result similar to the resistant standard BRS 256RR (Table 1).

Some genotypes had distinct mean gall intensity between evaluation periods. For example, the genotype CEPsRR 09086 had a gall intensity of 3.3 in the 1st planting date, and 1.7 in the 2nd. According to the rating scale provided by MAPA[8], in the first date this would be classified as a susceptible

Table 1. Intensity galls caused by Meloidogyne javanica in soybean genotypes evaluated in two planting dates, average of the two galls intensity reviews and genotype reaction to the nematode under field conditions.

GenotypesGall Intensity(1)

Mean IG (2) Reaction (3)

1ª date 2ª date

CEPsRR 07224 2.1 b(4) 1.5 b(4) 1.8 R

CEPsRR 08414 2.8 a 2.6 a 2.7 MR

CEPsBt 09018 2.8 a 2.2 b 2.5 MR

CEPsBt 09021 3.3 a 2.6 a 3.0 MR

CEPsBt 09030 2.1 b 2.0 b 2.1 MR

CEPsBt 09033 3.0 a 2.8 a 2.9 MR

CEPsBt 09036 2.4 b 1.8 b 2.1 MR

CEPsBt 09049 2.7 a 1.7 b 2.2 MR

CEPsRR 09086 3.3 a 1.7 b 2.5 MR

CEPsBt 10129 2.3 b 1.7 b 2.0 MR

FUNDACEP 58RR 1.9 b 0.9 c 1.4 R

FUNDACEP 64RR 2.6 a 1.7 b 2.2 MR

BRS 243RR 3.6 a 3.3 a 3.5 S

BRS 256RR 1.8 b 0.8 c 1.3 R

CV (%) 20.8 28.9

(1)Gall intensity: 0 = immune; 1 = one or two galls, normal root system; 2 = few small galls and undeveloped root system; 3 = small galls and slightly damaged root system; 4 = many galls and damaged root system; and 5 = root system completely taken by galls.(2)Average of the two galls intensity assessments.(3)R = resistant, MR = moderately resistant, S = susceptible[8].(4)Means followed by the same letter in the columns do not differ significantly by the Scott-Knott test at 5% significance level.



genotype and in the second as resistant. The genotypes that showed lower galls on both assessments (1st and 2nd dates) were CEPsRR 07224, CEPsBt 09030, CEPsBt 09036, CEPsBt 10129 and FUNDACEP 58RR, besides the standard BRS 256RR.

Considering the average of gall intensity in the two growing seasons, only CEPsRR 07224 and FUNDACEP 58RR genotypes were classified as resistant (R), along with the resistance pattern BRS 256RR. Moreover, only the susceptibility standard BRS 243RR was classified as susceptible (S). The others were classified as moderately resistant (MR).

Several studies use only the index/gall intensity in order to select soybean genotypes showing nematode gall resistance in the field, especially when evaluating large quantities of materials. Dall’Agnol & Antônio[16] assessed the response of 1144 soybean genotypes in soils naturally infested with M. javanica and M. incognita, using gall index as criteria, and selecting only 37 strains as resistant to M. javanica and M . incognita.

Based on the results for intensity of galls in this experiment, it can be established that the genotypes are resistant to M. javanica, since all were classified as resistant or moderately resistant. Besides the differences in the intensity of galls between the genotypes, visual differences were observed in the size of plants, especially among genotypes classified as resistant and susceptible (Figure 1a, b), and in the standard. In the susceptible standard, the roots were completely seized by galls of M. javanica, with a scale note of 5 (Figure 2a, b).

Although the evaluation of soybean genotypes under M. javanica naturally infested conditions closely matches field reality, some factors may have affected the results. Among these are the heterogeneity of inoculum distribution in the area and the adverse weather conditions, such as severe drought that occurred in the 2011/2012 harvest. These environmental changes, as well as the differences in the intensity of galls observed between the two planting dates, motivated the experiment in a greenhouse under further controlled conditions.

Figure 1. Soybean genotypes in area naturally infested with Meloidogyne javanica. (a) The soybean plant on the left is BRS 256RR, which is a resistant standard. On the right, BRS 243RR which is a susceptible standard. (b) On the left, FUNDACEP 64RR, which is a susceptible genotype, and on the right FUNDACEP 58RR which is resistant. Julio de Castilhos, RS, 2011/2012.

Figure 2. Standard of soybean roots susceptible BRS 243RR with top marks for intensity of galls. (a) Evaluation of the 1st season. (b) Evaluation of the 2nd season. Julio de Castilhos, RS, 2011/2012.



Evaluation in greenhouseConsidering the results obtained for the number of galls on roots, the genotypes were statistically

divided into five distinct groups (Table 2). Noteworthy are the CEPsBt 09036 and CEPsBt 10129 genotypes, along with the resistant standard BRS 256RR, followed by genotypes CEPsRR 07224, CEPsRR 08414, CEPsBt 09018, CEPsBt 09049 and FUNDACEP 58RR. BRS 243RR confirmed its susceptible behavior displaying the largest number of galls, as well as the highest average of gall index (GI), statistically higher than the other treatments. The lowest GI values were observed in genotypes CEPsBt 09036, CEPsBt 10129 and the resistant standard BRS 256RR. For egg mass number (EMN) in the roots, the genotypes CEPsBt 09033 CEPsBt 10129 and FUNDACEP 58RR had the lowest average, differing statistically even from the resistant standard, followed by genotypes CEPsBt 09018, CEPsBt 09021, CEPsBt 09030, CEPsBt 09036, CEPsBt 09049 and BRS 256RR. In this experiment the results of egg mass number (EMN) exhibited a relationship with the results obtained for the variables GI and RF. According to Lordello[17], the number and index of egg masses express the nematode reproduction in an estimated fashion, and is not entirely accurate, since egg masses may contain from a few to more than two thousand eggs.

The variables number of eggs and RF, except for FUNDACEP 64RR, were lower than those observed on the susceptible standard in all other, highlighting genotypes CEPsBt 09033, CEPsBt 09036 and CEPsBt 10129 that responded similarly to the resistant standard. The susceptible standard BRS 243RR and the FUNDACEP 64RR genotype had the highest number of eggs and reproduction factor values.

Genotypes CEPsRR 07224, CEPsRR 08414 and FUNDACEP 58RR, although they had relatively low numbers of galls (13, 13 and 16, respectively), seem to be good multipliers of M. javanica with RF> 2. In practical terms, cultivation of these genotypes could double the population of nematodes in the planted area.

Dias et al.[18], while testing the response of soybean to M. enterolobii and M. ethiopica observed, in a general manner, a positive correlation between GI and RF for both nematodes, but in the case of

Table 2. Variables used for classification of soybean genotypes reaction as to infection by Meloidogyne javanica and average results of the evaluations in the greenhouse.

Genotypes Gall number(1) GI (2) MNE (3) Eggs Number (4) RF (5) Response (6)

CEPsRR 07224 13 d(7) 2.8 d(7) 83 a(7) 11674 b(7) 2.92 b(7) S(8)

CEPsRR 08414 13 d 2.6 d 83 a 13371 b 3.34 b S

CEPsBt 09018 12 d 2.5 d 69 b 7741 c 1.94 c S

CEPsBt 09021 22 c 3.0 c 65 b 8102 c 2.03 c S

CEPsBt 09030 30 b 3.4 b 59 b 8807 c 2.20 c S

CEPsBt 09033 23 c 3.0 c 48 c 5258 d 1.32 d S

CEPsBt 09036 10 e 2.4 d 62 b 5335 d 1.33 d S

CEPsBt 09049 12 d 2.5 d 63 b 8819 c 2.21 c S

CEPsRR 09086 26 b 3.3 b 83 a 8561 c 2.14 c S

CEPsBt 10129 9 e 2.1 e 39 c 4444 d 1.11 d S

FUNDACEP 58RR 16 d 2.8 d 48 c 9507 c 2.38 c S

FUNDACEP 64RR 30 b 3.4 b 94 a 15077 a 3.77 a S

BRS 243RR 48 a 4.0 a 92 a 17598 a 4.40 a S

BRS 256RR 8 e 2.2 e 67 b 5148 d 1.29 d S

CV (%) 17.5 16.1 29.0 18.2 18.2

(1)Number of galls per root.(2)Galls index proposed by Taylor & Sasser[11].(3)Number of egg masses.(4)Number of eggs.(5)reproduction factor = final population / initial population (Pi = 4000). Oostenbrink[13].(6)Response according to the RF, where RF <1.00 = resistant and RF> 1.00 = susceptible. Oostenbrink[13].(7)Means followed by the same letter do not differ by the Scott-Knott test at 5% significance.(8)S = susceptible. Oostenbrink[13].



M. enterolobii, there were exceptions. The cultivar MG/BR-46 showed low GI and relatively high RF, while cultivars BRS 213, BRS Corisco and Ocepar 4 Iguaçu showed an opposite behavior, with high GI and a relative low RF.

Considering only results from GI[11] evaluations, CEPsBt 09036 and CEPsBt 10129 genotypes and the standard BRS 256RR were classified as resistant (R), with a GI value of 2. The remaining soybean genotypes would be classified as susceptible (S), with GI values between 3 and 4.

Although there are genotypes where GI does not correlate with RF, soybean’s genetic breeding programs typically select the Meloidogyne spp. resistant material based only on GI, due to the large number of lines to be tested (thousands). This is justified, since GI is an easy to determine parameter allowing also to promptly evaluate large number of lines[18]. The GI is also the standard parameter in assay protocols to evaluate the response of soybean genotypes to root-knot nematodes by the National Service for Plant Variety Protection[8], and is used as a parameter for genetic improvement.

The gall index value is an important information, it allows the producer to use a soybean cultivar with low GI (≤2) in an area infested by gall nematodes, and still expect near to normal production without major yield reductions. However, it should be noted that the choice of soybean cultivars based solely on GI does not take into account the multiplication of the nematode. Over the years, depending on the RF of the cultivars, the planted area may become totally unfeasible for production because of the multiplication and increase of the nematode’s population. Thus, the information about the RF is also important in order to choose the soybean cultivars to be planted.

In this experiment all cultivars showed a RF> 1, and would be classified as susceptible[13] (Table 2), since they all reproduced the nematode. Similar results were obtained by Asmus & Andrade[19] in experiments with soybean cultivars recommended for Mato Grosso, where all genotypes showed a significant number of M. javanica eggs per gram of root and RF> 1, characterizing its susceptibility to nematodes.

Despite the valuable results obtained, and the relevance of knowing the nematode’s RF for cultivar response to be used by the farmer, assessments carried out based only on the RF value may categorize soybean genotypes as resistant, while sometimes being intolerant. According to Silva[5], when quantifying only the nematode’s reproductive rate in soybean genotypes, it is impossible to separate resistance from intolerance, since in both cases the reproduction rate is low. However, in the resistant plants, the development is normal while in the intolerants, it is compromised.

Classifying genotypes by resistance against gall nematodes, performed using more than one variable, shows with higher accuracy the genotype response to them, once it is possible to consider not only the damage to the host by the nematode, but also the reproduction of the nematode within the host[1]. The response of genotypes to M. javanica, based on the scale of Canto-Sáenz[14], which considers GI and RF, may allow to distinguish CEPsBt 09036 and CEPsBt 10129 genotypes evaluated in this study as being tolerant, as well as the standard BRS 256RR. The other materials were classified as susceptible, because they rendered values of GI> 2 and RF> 1 (Table 3). The scale from Canto-Sáenz[14] was also used by Dias et al.[6] while evaluating a relatively small number of genotypes, when it was still possible to determine the parameters RF and GI to characterize the reactions. According to Canto-Sáenz[14], the RF and the degree of injuries to the host are more effective criteria to evaluate the reaction of plants to gall nematodes.

Similar results based on the same criteria were also found by Soares & Santos[7], where the reaction of 11 soybean cultivars to a population of M. javanica, resulted in only one cultivar (BRSMG Garantia) that responded as tolerant; the others, although they were considered susceptible, showed RF values above and close to 1, indicating, according to the authors, lower susceptibility. This is an important information, because as suggested by Asmus & Andrade[19], in the absence of resistant cultivars to M. javanica in areas infested with the nematodes, selection must be favored within cultivars that do not allow a high reproduction of this nematode.

Despite limitations, the use of GI has already enabled the development of many soybean resistant or moderately resistant cultivars to Meloidogyne incognita and/or M. javanica in Brazil. Especially in the case of M. javanica where almost all these cultivars exhibit, although low values, a RF>1[18]. Moreover, there is higher availability of cultivars with different degrees of resistance to M. incognita than to M. javanica[6].

Among the possible explanations for obtaining conflicting results with those in the available literature is the use of different evaluation criteria[14]. Some authors perform the classification of soybean genotypes, as well as other cultures, according to results obtained using GI, others use RF and still others use the two (GI and RF). In addition, another factor that may interfere and produce inconsistent results is the difference in aggressiveness of the nematode populations used, a quality that is local variable[20].



CONCLUSIONBased on the results obtained in this work in field and greenhouse conditions, the soybean genotypes

CEPsBt 09036 and CEPsBt 10129, responded as tolerant. Both genotypes show similar results as the resistant standard BRS 256RR, demonstrating a great potential for their adoption by soybean producers having M. javanica infested areas.

REFERENCES1. Companhia Nacional de Abastecimento – Conab. 2012. [online]. Accessed on July 13, 2012. Available from: http://

www.conab.gov.br

2. Empresa Brasileira de Pesquisa Agropecuária – Embrapa. 2011. Tecnologias de produção de soja região central do Brasil. Embrapa Soja, Londrina, 255 pp.

3. Ferraz LCCB. 2001. As meloidoginoses da soja: passado, presente e futuro. In: Silva JFV, Mazaffera P, Carneiro RG, Asmus GL, Ferraz LCCB (eds.). Relações parasito-hospedeiro nas meloidoginoses da soja. Embrapa Soja, Sociedade de Nematologia, Londrina, p. 15-38

4. Dias WP, Garcia A, Silva JFV, Carneiro GES. 2010. Nematóides em soja: identificação e controle. Circular Técnica, 76. Embrapa Soja, Londrina, 8 pp.

5. Silva JFV. 2001. Resistência genética da soja a nematóides do gênero Meloidogyne. In: Silva JFV, Mazaffera P, Carneiro RG, Asmus GL, Ferraz LCCB (eds.). Relações parasito-hospedeiro nas meloidoginoses da soja. Embrapa Soja, Londrina, 127 pp.

6. Dias WP, Asmus GL, Silva JFV, Garcia A, Carneiro GES. 2010. Nematóides. In: Almeida AMR, Seixas CDS (eds.). Soja: doenças radiculares e de hastes e inter-relações com o manejo do solo e da cultura. Embrapa Soja, Londrina, p. 173-206.

7. Soares PLM, Santos JM. 2009. Reação de cultivares de soja a uma população de Meloidogyne javanica. Bioscience Journal, 25: 33-36.

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9. Hussey R, Barker KR. 1973. A comparations of methods of collecting inocula of Meloidogyne spp. Including a new technique. Plant Disease Reporter, 57: 1025-1028.

Table 3. Response of soybean genotypes to M. javanica as Canto-Sáenz criteria[14] in the greenhouse.

Genotypes GI(1) RF(2) Reaction(3)

CEPsRR 07224 3 2.92 S

CEPsRR 08414 3 3.34 S

CEPsBt 09018 3 1.94 S

CEPsBt 09021 3 2.03 S

CEPsBt 09030 3 2.20 S

CEPsBt 09033 3 1.32 S

CEPsBt 09036 2 1.33 T

CEPsBt 09049 3 2.21 S

CEPsRR 09086 3 2.14 S

CEPsBt 10129 2 1.11 T

BRS 243RR 4 4.40 S

BRS 256RR 2 1.29 T

FUNDACEP 58RR 3 2.38 S

FUNDACEP 64RR 3 3.77 S

(1)Galls Index.(2)Reproduction factor = final population / initial population.(3)HS = hipersuscetíveis (GI> 2 and RF ≤ 1), S = susceptible (GI> 2 and RF> 1), T = tolerant (GI ≤ 2 and RF> 1) and R = resistant (GI ≤ 2 and RF ≤ 1).



10. Boneti JI, Ferraz S. 1981. Modificações no método Hussey & Barker para extração de ovos de Meloidogyne exigua, em raízes de cafeeiro. Fitopatologia Brasileira, 6: 553.

11. Taylor AL, Sasser JN. 1978. Biology, identification and control of root-knot nematodes. NCSU Graphics, Raleigh, 111 pp.

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13. Oostenbrink M. 1966. Major characteristic of the relation between nematodes and plants. Mededelingen Landbouwhogeschool, Wageningen, 46 pp.

14. Canto-Sáenz M. 1985. The nature of resistance to Meloidogyne incognita. In: Sasser JN, Carter CC (eds.). An advanced treatise on Meloidogyne. Biology and control, 1. North Carolina State University Graphics, Raleigh, p. 225-231.

15. Canteri MG, Althaus RA, Virgens JS Fo, Giglioti EA, Godoy CV. 2001. SASM-Agri: sistema para análise e separação de médias em experimentos agrícolas pelos métodos Scott - Knott, Tukey e Duncan. Revista Brasileira de Agrocomputação, 1: 18-24.

16. Dall’Agnol A, Antônio H. 1983. Grau de suscetibilidade de genótipos de soja aos nematóides Meloidogyne incognita e Meloidogyne javanica. Nematologia Brasileira, 7: 15-89.

17. Lordello LGE. 1982. Nematóides das plantas cultivadas. 7th. ed. Nobel, São Paulo, 314 pp.

18. Dias WP, Freitas VM, Ribeiro NR, Moita AW, Homechin M, Parpinelli MB, Carneiro RMDG. 2010. Reação de genótipos de soja a Meloidogyne enterolobii e M. ethiopica. Nematologia Brasileira, 34: 220-225.

19. Asmus GL, Andrade PJM. 1997. Reação a Meloidogyne javanica de algumas cultivares de soja recomendadas para o Estado de Mato Grosso. Boletim de Pesquisa, 2. Embrapa Agropecuária Oeste, Dourados, 20 pp.

20. Tihohod D, Ferraz S. 1986. Variabilidade de três populações de Meloidogyne javanica em plantas de soja. Nematologia Brasileira, 10: 163-171.

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