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First reppport and additional information of
meloidogyne konaensis parasiting different crops in
Brazil
J. Monteiro, J. E. Cares, A. C. M. M. Gomes, V. R. Correa, M. F. A. Santos,
M. D. G. Carneiro, G. Gomez, C. D. G. Santos, Philippe Castagnone, R. M.
D. G. Carneiro
To cite this version:
J. Monteiro, J. E. Cares, A. C. M. M. Gomes, V. R. Correa, M. F. A. Santos, et al.. First reppport and
additional information of meloidogyne konaensis parasiting different crops in Brazil. Joint Meeting
of the Society of Nematologists and the Organization of Nematologists of Tropical America (ONTA),
2016, Jul 2016, Montréal, Canada. 387 p. �hal-01594530�
determine drenching frequency of VCT to suppress RKN in a cucumber (Cucumis sativus) agroecosystem. Cucumber plants were drenched at 1-, 2- or 4-week intervals and compared to a water control. In both trials, drenching VCT at 1-week intervals suppressed (P# 0.05) RKN but not reniform (Rotylenchulus reniformis) nematodes. VCT could induce host-plant resistance, consequently two split-root experiments were conducted in the greenhouse. Cucumber root penetration by ofM. incognita was reduced by VCT drenching. Quantitative real time PCR was used to detect the expression of the defense related genes CHIT-1 and PAL-1 encoding chitinase and phenylalanine ammonia-lyase, respectively. Cucumbers were drenched with VCT from uncured vermicompost 2 days prior toM. incognita inoculation. Gene expression levels in leaves were determined at 0 hr, 1, 2, 5 and 8 days post nematode inoculation. Plants drenched with VCT showed an increased expression ofCHIT-1 at 2 days afterM. incognita inoculation, and increased expression of PAL-1 at 0, 1, 2 and 8 days after M. incognita inoculation. Additional assays were conducted to study the expression of b-1,3-Glucanase, LOX-1 and PR-1 encoding glucanase, lipoxygenese, and pathogenesis-related protein 1 respectively. These experiments suggested that VCT prepared from un-cured vermicompost has the potential to induce host-plant resistance against RKN. Although this induction was short in duration, drenching VCT at a weekly interval provided significant and consistent suppression of root-knot nematodes throughout a cucumber crop. Thus, use of VCT prepared from an uncured vermicompost is a viable post-plant nematode management tool against RKN. Future work could include applying VCT through fertigation and modifying feed stock of vermicompost to achieve reniform nematode suppression by VCT.
PHLOROGLUCINOL (1,3,5-TRIHYDROXYBENZENE) ENHANCED THE AMELIORATES STRESS RESISTANCE AND REDUCEDb-AMYLOID TOXICITY IN CAENORHABDITIS ELEGANS. Mohankumar, A1., G. Shanmugam1, P. Sundararaj1, S.L. Hafez2and Nivitha Sundararaj3.1Unit of Nematology, Department of Zoology, Bharathiar Uni-versity, Coimbatore;2U of I Parma REC, 29603 U of I Lane, Parma, ID 83660, USA3Kumaraguru College of Technology, Coimbatore, India.
Phloroglucinol (PG), found in brown algae (Phaeophyceae), is a monomeric unit of phlorotannins with antioxidant, anti-inflammatory, anti-diabetic, antimicrobial, anti-allergic and anti-viral properties. An attempt has been made to study the effect of PG on the lifespan, health, b-Amyloid toxicity and oxidative stress tolerance on the nematode model Caeno-rhabditis elegans. Various concentrations of PG viz, 10mM, 50mM, 100mM, 200mM, 400mM, 800mM, 1000mM were prepared using DMSO (final concentration to be maintained at 0.2%) and treated on C. elegans. For lifespan assay, C. elegans eggs were transferred to the NGM plates previously treated with or without PG and E. coli OP50 and maintained at 208C. Synchronization was performed at L4 larvae stage, and young L4 larvae were transferred to fresh plates with different PG concentrations (40 worms per plate with a total of 3 plates per treatment). Worms were observed daily for survival and transferred to fresh treatment plates until the last worms dead. At 400mM PG, the mean lifespan of wild type N2 and mev-1C. elegans increased while there was no increase in longevity of daf-16 mutant worms. Exposure of wild C. elegans to PG at 400mM did not induce any changes in body length, morphology, brood size, locomotion or mortality while there was a significant decrease in lipofuscin accumulation. Pre-treatedC. elegans with PG suppressed the damage due to heat stress and oxidative stress induced by an ROS generator, Juglone (500mM). PG treated worms had increased fluorescence intensity of HSP-16.2 and SOD-3 proteins compared to untreated control strains of CL2070 and CF1553 respectively. PG delayed the amyloid-b induced paralysis up to 25.4% compared to control worms in transgenic C. elegans strain CL4176 expressing human Amyloidb1-42. Thus, the results suggest that the insulin/IGF-1 signalling and their downstream and mitochondrial
respiratory chain pathways are involved in the mechanism of life extension and stress tolerance mediated by PG.
FIRST REPPORT AND ADDITIONAL INFORMATION OF MELOIDOGYNE KONAENSIS PARASITIZING
DIFFERENT CROPS IN BRAZIL. Monteiro, J.1, J.E. Cares1, A.C.M.M. Gomes2, V.R. Correa2, M. F. A. Santos2, M.D.G. Carneiro2, G. Gomez2, C.D.G. Santos3, and P. Castagnone-Sereno4, and R.M.D.G. Carneiro2. 1Departamento de Fitopatologia, Universidade de Brasılia, Brasılia DF 70910-900, Brazil,2EMBRAPA- Recursos Geneticos e Biotecnologia, CP.02372 Brasılia DF 70849-970, Brazil,3Departamento de Fitopatologia, Universidade Federal do Ceara, Fortaleza CE 60020-181, 4INRA, Univ. Nice Sophia Antipolis, CNRS, UMR 1355-7254, Institut Sophia Agrobiotech, 06900 Sophia Antipolis, France.
In a survey forMeloidogyne spp. in different crops from eleven regions at Ceara State, Brazil using esterase isozyme electrophoresis as a specific identification method, four atypical populations were characterized from cabbage, papaya, noni and canapum plants, which showed an esterase profile different from those previously detected in Brazil. Morphological studies showed typical characteristics of the specie Meloidogyne konaensis. Perineal patterns of females were variable, similar toM. arenaria and M. incognita, stylet length 14-20mm, the knobs gradually merging with the shaft and the dorsal esophageal gland orifice (DEGO) ranging from 4-7 mm, are some characteristics of females. Although males are not frequently found, the stylet morphology provides the most useful source of diagnostic character for the specie, with 6-12 large projections protruding from the shaft. The esterase pattern K3 is unique and species-specific with three major bands Rm 1.0, 1.17, 1.27 and a secondary band Rm 1.10. Some confusion about the true identity of this species was clarified in this study including the differentiation fromM. paranaensis. A species-specific SCAR marker developed for M. paranaensis was Abstracts 353
tested and no amplification products were observed. In Neighbour-Joining analyses of ITS and D2-D3 rRNA sequences,M. konaensis from Brazil appeared clearly separated from M. paranaensis. Pathological tests indicated that coffee is not a host of M. konaensis as previously reported in the original description of this species.
FIRST REPORT OF ENDOTOKIA MATRICIDA INMELOIDOGYNE HAPLA: A STUDY CASE. Monteiro, T.S.A.1, J.A. Brito2, S.J.S. Vau4, W. Yuan2, J.A. LaMondia3, and D.W. Dickson4.1Plant Path. Dept., Univ. of Vicosa, Vicosa, MG, 36570-900, Brazil, 2Div. of Plant Industry, FDACS, Gainesville, FL 32614-7100; 3Connecticut Agri. Exp. Sta., Windsor, CT 06095,4Entomology and Nematology Dept., Univ. of Florida, Gainesville, FL 32611-0620.
Endotokia matricida is a phenomenon known to occur when embryogenesis and egg hatching takes place within the nematode uterus. This phenomenon is known to occur within the Rhabidita, but it is very uncommon among plant- parasitic nematodes. This phenomenon was observed in a population ofMeloidogyne hapla, originally collected in Connecticut, USA and reared on tomato ‘Rutgers’ maintained at 24C for 60 days in a growth room. Out of 974 females examined, only 14 showed this phenomenon or 1.44%. Eggs at different stages of development, including first-stage juveniles within the egg and second-stage juveniles (J2) were observed inside of the female body cavity. The highest number of J2 and eggs observed per female showing endotokia matricida was 57 and 350, respectively. However, the average number of J2/female was 13, whereas the average number of eggs/female was 90. These findings suggest that this phenomenon is not common in the population ofM. hapla used in this study. To the best of our knowledge this is the first report of endotokia matricida in M. hapla.
VIRAL INFECTION IN NEMATHOPHAGOUS FUNGUS POCHONIA CHLAMYDOSPORIA. Monteiro, T.S.A.1, A.P. Oliveira2, A.S. Xavier1, P. Alfenas-Zerbini2and L.G. Freitas1.1Plant Pathology Dept., University of Vicxosa, Vicxosa, MG, 36570-900, Brazil,2Microbiology Dept., University of Vicxosa, Vicxosa, MG, 36570-900, Brazil.
Pochonia chlamydosporia is a nematophagous fungus which has been widely studied because of its ability to reduce nematode populations and to promote plant growth. The differences in the virulence against nematodes, common among isolates ofP. chlamydosporia, may be due to the genetic constitution or to the interactions with other microorganisms or the environment. The mycoviruses cause cryptic infections and may be responsible for alterations in the fungus aggressiveness (hypo/hypervirulence). TheP. chlamydosporia isolate PCM4 was the only infected out of 12 investigated. The virus found has a standard complex dsRNAs, multisegmented or a mixed infection. In a greenhouse experiment, this strain failed to reduce the population of the root-knot nematode,Meloidogyne javanica. These findings infer the importance of indexing when screening isolates for biological control of nematodes. Future trials using a virus-free line of PCM4 would help to understand if the low nematode antagonism in this isolate is the result of the viral infection or not. This is the first report of a mycovirus infectingP. chlamydosporia.
HOW LOCAL SCALE VARIATION INFLUENCES NEMATODE COMMUNITY STRUCTURE IN THE FYNBOS MEDITERRANEAN HEATHLAND OF SOUTH AFRICA. Moroenyane, I.1, K. Dong2, S.B.M. Chimphango3, D. Singh4, and J.M. Adams2.1Institut National de la Recherche Scientifique, Centre INRS-Institut Armand-Frappier, 531 Boulevard de Prairies, Laval, Quebec, H7V 1B7,2Department of Biological Sciences, College of Natural Sciences, Seoul
National University, Seoul 151-742, South Korea,3Department of Biological Sciences, University of Cape Town, Cape Town, South Africa, 7700,4Environmental Genomics Division, CSIR-NEERI, Nehru Marg, Nagpur (MH), 440020, India. The Fynbos biome of South Africa is renowned for its high levels of plant diversity, endemism, and heterogeneous soils. Studies have elucidated the broad taxonomic classification and diversity patterns of soil nematodes in Fynbos. However, majority of these studies have only looked at the diversity of plant feeding nematode, and none have compared the com-munity of free-living nematodes from different Fynbos types. We used a novel metagenetic approach to investigate variation in nematode community structure in the Fynbos vegetation. We compared 23 samples of soil nematode communities from five different Fynbos vegetation types. Nematode DNA was 454- pyrosequenced for the 18S rRNA gene. Here we show that soils from Fynbos sites (Alluvial, Sand, Limestone, Shale, and Sandstone) have distinct properties and how these influence the nematode community structure and diversity. Previous studies of free-living nematode, revealed great diversity and differentiation of nematode community structure along an environmental gradient. We found that the diversity (Shannon and Simpson index) was overall significant, but there was no difference between sites and there was no environmental gradient that seemed to delimit this diversity. Similarly, the relative abundance of dominant nematode families did not vary across sites, with the exception ofTylenchidae. The relative abundance of feeding guilds also did not vary across sites; interestingly, only plant feeding nematodes significantly varied and were negatively correlated with NH4. Furthermore, the nematode
community based on Bray Curtis distance did not cluster by Fynbos vegetation type and was significantly influenced by potassium (K) and sulphate (SO4). However, the phylogenetic signal detected that closely related taxa in Fynbos tend to
co-occur more often than expected by chance. Unifrac analyses also did not cluster by vegetation type, but was influenced by geographical distance. It seems that in the Fynbos there has been very little phylogenetic divergence (ecological and genetic drift) of nematode lineages. Furthermore, at local scale the ses.NTI (nearest taxon index) was significantly higher than null expectations, indicating that co-occurrence of related nematode lineages is determined by the differences in environmental 354 Journal of Nematology, Volume 48, No. 4, December 2016
