Characterisation of a Meloidogyne species complex parasitising rice in southern Brazil

Nematology ◽  
2017 ◽  
Vol 19 (4) ◽  
pp. 403-412 ◽  
Author(s):  
Rafael R.R.D. Negretti ◽  
Cesar B. Gomes ◽  
Vanessa S. Mattos ◽  
Lúcia Somavilla ◽  
Roberta Manica-Berto ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Phylogenetic Analyses ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Irrigated Rice ◽  
Parthenogenetic Species ◽  
Phylogenetic Studies ◽  
Rice Samples ◽  
Relationship Of ◽  
Esterase Phenotypes

Root-knot nematodes (RKN) are important plant pathogens affecting rice in South-East Asia and southern Brazil in irrigated rice fields. In order to investigate the specific diversity of RKN associated with irrigated rice in southern Brazil, Meloidogyne spp. from Rio Grande do Sul (RS) and Santa Catarina (SC) States were characterised biochemically by esterase (Est) and malate dehydrogenase (Mdh) phenotypes. Fifty-six Meloidogyne spp. populations were detected in 48% of rice samples, and a total of five esterase phenotypes were identified, four of which presented as drawn-out bands in different positions. In RS State, M. graminicola (Est VS1), Meloidogyne sp. 2 (Est R2) and Meloidogyne sp. 3 (Est R3) were identified, which corresponded to ca 80, 40 and 10% of samples, respectively. In SC State, M. graminicola, M. javanica (Est J3), Meloidogyne sp. 1 (Est R1), Meloidogyne sp. 2 and Meloidogyne sp. 3 accounted for ca 93.75, 12.50, 62.50, 12.25 and 6.25% of samples, respectively. The esterase phenotypes R1, R2 and R3 are new, never having been detected on rice before. Meloidogyne javanica showed a N1 Mdh phenotype (Rm: 1.0), while four other populations exhibited a N1a (Rm: 1.4) phenotype. All populations were tested with two SCAR markers specific to M. graminicola, which confirmed that, but no specificity was obtained with both markers in relation to the atypical populations analysed. Sequencing and phylogenetic analyses of internal transcribed spacer-rRNA (ITS) were performed to infer the phylogenetic relationship of these atypical Meloidogyne spp. populations. Meloidogyne sp. 1 grouped with the mitotic parthenogenetic species, while the two others (Meloidogyne sp. 2 and sp. 3) clustered with M. graminicola and other meiotic parthenogenetic species. Taken together, these data highlight the unprecedented specific diversity of RKN associated with irrigated rice in southern Brazil. Further morphological and phylogenetic studies involving these atypical isolates will be carried out to identify this complex of species.

scholarly journals Aeschynomene spp. Identification and Weed Management in Rice Fields in Southern Brazil

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 453
Author(s):  
Matheus B Martins ◽  
Dirceu Agostinetto ◽  
Silvia Fogliatto ◽  
Francesco Vidotto ◽  
André Andres
Keyword(s):  
Weed Management ◽  
Chemical Control ◽  
Management Practices ◽  
Rice Fields ◽  
Extension Agents ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Irrigated Rice ◽  
Irrigation Uniformity ◽  
Mature Seeds

In 2002, a survey carried out in rice paddies in the Rio Grande do Sul (RS) state reported the occurrence of nine species of jointvetch (Aeschynomene). Due to their semi-aquatic habit, some species adapted to irrigated rice fields, which led to their being considered the worst broadleaf weed in RS. Although farmers have successfully implemented weed management practices, Aeschynomene plants have reportedly escaped chemical control. This study aims to identify the species of Aeschynomene that occur in rice fields in RS and to evaluate the reasons why escapes are occurring. A survey was carried out by collecting mature seeds from individual adult plants. A questionnaire on the management practices employed in each field was administered to 54 farmers and 18 extension agents, each of whom was responsible for one of the surveyed rice fields. This survey found four species of Aeschynomene are present in rice fields in RS: A. denticulata, A. indica, A. rudis, and A. sensitiva. The results suggest that the explanation for escapes may lie in the management practices adopted by farmers, which are focused on the control of weedy grasses. Escapes are also associated with problems such as the lack of irrigation uniformity and out-of-stage, late herbicide applications.

Tropicoporus stratificans sp. nov. (Hymenochaetales, Basidiomycota) from southern Brazil

Phytotaxa ◽  
2016 ◽  
Vol 245 (2) ◽  
pp. 144 ◽  
Author(s):  
Gilberto Coelho ◽  
ANDRESSA DE OLIVEIRA SILVEIRA ◽  
ZAIDA INÊS ANTONIOLLI ◽  
EUGENE YURCHENKO
Keyword(s):  
New Species ◽  
Maximum Likelihood ◽  
Phylogenetic Analyses ◽  
Wood Decay ◽  
Rio Grande ◽  
New Taxon ◽  
Nrdna Its ◽  
Decayed Wood ◽  
Southern Brazil ◽  
Rio Grande Do Sul

Tropicoporus is a recently proposed genus that was segregated from Inonotus s.l. and includes species with important wood decay and medicinal functions. The description of T. stratificans sp. nov. is based on more than 10 specimens collected on fallen decayed wood in subtropical forests of Rio Grande do Sul State. The species is recognized by its resupinate, poroid, golden brown, perennial basidiomes that become multi-layered, dimitic hyphal system, abundant hymenial setae, and subglobose to ellipsoid, brownish-yellow to ferruginous-brown basidiospores. Based on nrDNA ITS sequences, Bayesian and maximum likelihood phylogenetic analyses of Tropicoporus nested the new taxon in the T. linteus clade. A description and illustrations of the new species are provided.

scholarly journals Aquatic Oligochaeta (Annelida: Clitellata) in wetlands and irrigated rice fields in the state of Rio Grande do Sul (Southern Brazil)

2021 ◽  
Vol 111 ◽  
Author(s):  
Mateus Marques Pires ◽  
Elisangela Secretti ◽  
Guilherme Rossi Gorni ◽  
Nathalie Aparecida de Oliveira Sanches ◽  
Carla Bender Kotzian
Keyword(s):  
New Records ◽  
Rio Grande ◽  
The State ◽  
Rice Fields ◽  
Aquatic Oligochaeta ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Irrigated Rice ◽  
Distribution Ranges ◽  
Stylaria Lacustris

ABSTRACT The knowledge of the diversity and distribution of aquatic Oligochaeta (Annelida: Clitellata) species is scarce in southern Brazil. This study presents a list of the species of aquatic Oligochaeta in wetlands and irrigated rice fields in the state of Rio Grande do Sul. Collections were carried out in two large wetland remnants and seven irrigated rice fields distributed in three regions across the state. We recorded eight species from two families (Alluroididae and Naididae). We expanded the distribution ranges of two species (Brinkhurstia americana and Stylaria lacustris), which represent new records for the state of Rio Grande do Sul and registered their occurrence in non-documented environments. In specific, the present study increases to 24 species the aquatic Oligochaeta diversity for the state of Rio Grande do Sul. In addition, the spatial distribution of the species recorded suggests that rice fields support a subset of the wetland fauna of aquatic Oligochaeta. The results provide important information on the ecology and distribution of limnic Oligochaeta and are useful to inform on the diversity of this fauna in agroecosystems.

scholarly journals The Complete DNA Sequence of the Mitochondrial Genome of a “Living Fossil,” the Coelacanth (Latimeria chalumnae)

Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 995-1010 ◽  
Author(s):  
Rafael Zardoya ◽  
Axel Meyer
Keyword(s):  
Mitochondrial Genome ◽  
Tandem Repeats ◽  
Phylogenetic Analyses ◽  
Large Data ◽  
Molecular Data ◽  
Phylogenetic Position ◽  
Data Set ◽  
Living Fossil ◽  
Latimeria Chalumnae ◽  
Relationship Of

The complete nucleotide sequence of the 16,407-bp mitochondrial genome of the coelacanth (Latimeria chalumnae) was determined. The coelacanth mitochondrial genome order is identical to the consensus vertebrate gene order which is also found in all ray-finned fishes, the lungfish, and most tetrapods. Base composition and codon usage also conform to typical vertebrate patterns. The entire mitochondrial genome was PCR-amplified with 24 sets of primers that are expected to amplify homologous regions in other related vertebrate species. Analyses of the control region of the coelacanth mitochondrial genome revealed the existence of four 22-bp tandem repeats close to its 3′ end. The phylogenetic analyses of a large data set combining genes coding for rRNAs, tRNA, and proteins (16,140 characters) confirmed the phylogenetic position of the coelacanth as a lobe-finned fish; it is more closely related to tetrapods than to ray-finned fishes. However, different phylogenetic methods applied to this largest available molecular data set were unable to resolve unambiguously the relationship of the coelacanth to the two other groups of extant lobe-finned fishes, the lungfishes and the tetrapods. Maximum parsimony favored a lungfish/coelacanth or a lungfish/tetrapod sistergroup relationship depending on which transversion:transition weighting is assumed. Neighbor-joining and maximum likelihood supported a lungfish/tetrapod sistergroup relationship.

A 12-year study of fungal infections in Rio Grande do Sul, Southern Brazil

2019 ◽  
Vol 36 (2) ◽  
pp. 55-60 ◽  
Author(s):  
Vanessa da Silva Fay ◽  
Tatiana Schäffer Gregianini ◽  
Ana Beatriz Gorini da Veiga ◽  
Stela Maris Bottin Gonçalves ◽  
Diana Mara Rodrigues ◽  
...  
Keyword(s):  
Fungal Infections ◽  
Rio Grande ◽  
Southern Brazil ◽  
Rio Grande Do Sul

Molecular Detection of Trypanosoma kaiowa in Tabanus triangulum (Diptera: Tabanidae) from the Coastal Plain of Rio Grande do Sul, Southern Brazil

2021 ◽  
Author(s):  
Gratchela D. Rodrigues ◽  
Eduardo Blodorn ◽  
Ândrio Zafalon-Silva ◽  
William Domingues ◽  
Roberta Marques ◽  
...  
Keyword(s):  
Coastal Plain ◽  
Molecular Detection ◽  
Rio Grande ◽  
Southern Brazil ◽  
Rio Grande Do Sul

Multigene phylogenetic analyses including diverse radiolarian species support the “Retaria” hypothesis — The sister relationship of Radiolaria and Foraminifera

2011 ◽  
Vol 81 (1-2) ◽  
pp. 32-42 ◽  
Author(s):  
Yoshiyuki Ishitani ◽  
Sohta A. Ishikawa ◽  
Yuji Inagaki ◽  
Masashi Tsuchiya ◽  
Kozo Takahashi ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Sister Relationship ◽  
Relationship Of

scholarly journals The first mitochondrial genome of the genus Exhippolysmata (Decapoda: Caridea: Lysmatidae), with gene rearrangements and phylogenetic associations in Caridea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying-ying Ye ◽  
Jing Miao ◽  
Ya-hong Guo ◽  
Li Gong ◽  
Li-hua Jiang ◽  
...  
Keyword(s):  
Mitochondrial Genome ◽  
Gene Order ◽  
Phylogenetic Analyses ◽  
Complete Mitochondrial Genome ◽  
Bootstrap Support ◽  
Trna Genes ◽  
Gene Rearrangements ◽  
Phylogenetic Studies ◽  
Gc Skew ◽  
Strong Bootstrap Support

AbstractThe complete mitochondrial genome (mitogenome) of animals can provide useful information for evolutionary and phylogenetic analyses. The mitogenome of the genus Exhippolysmata (i.e., Exhippolysmata ensirostris) was sequenced and annotated for the first time, its phylogenetic relationship with selected members from the infraorder Caridea was investigated. The 16,350 bp mitogenome contains the entire set of 37 common genes. The mitogenome composition was highly A + T biased at 64.43% with positive AT skew (0.009) and negative GC skew (− 0.199). All tRNA genes in the E. ensirostris mitogenome had a typical cloverleaf secondary structure, except for trnS1 (AGN), which appeared to lack the dihydrouridine arm. The gene order in the E. ensirostris mitogenome was rearranged compared with those of ancestral decapod taxa, the gene order of trnL2-cox2 changed to cox2-trnL2. The tandem duplication-random loss model is the most likely mechanism for the observed gene rearrangement of E. ensirostris. The ML and BI phylogenetic analyses place all Caridea species into one group with strong bootstrap support. The family Lysmatidae is most closely related to Alpheidae and Palaemonidae. These results will help to better understand the gene rearrangements and evolutionary position of E. ensirostris and lay a foundation for further phylogenetic studies of Caridea.

scholarly journals Mealybug Transmission of Grapevine Leafroll Viruses: An Analysis of Virus–Vector Specificity

2010 ◽  
Vol 100 (8) ◽  
pp. 830-834 ◽  
Author(s):  
Chi-Wei Tsai ◽  
Adib Rowhani ◽  
Deborah A. Golino ◽  
Kent M. Daane ◽  
Rodrigo P. P. Almeida
Keyword(s):  
Plant Pathogens ◽  
Phylogenetic Analyses ◽  
Virus Vector ◽  
Disease Spread ◽  
Virus Species ◽  
Vector Species ◽  
Vector Transmission ◽  
Planococcus Ficus ◽  
Grapevine Leafroll Disease ◽  
Leafroll Disease

To understand ecological factors mediating the spread of insect-borne plant pathogens, vector species for these pathogens need to be identified. Grapevine leafroll disease is caused by a complex of phylogenetically related closteroviruses, some of which are transmitted by insect vectors; however, the specificities of these complex virus–vector interactions are poorly understood thus far. Through biological assays and phylogenetic analyses, we studied the role of vector-pathogen specificity in the transmission of several grapevine leafroll-associated viruses (GLRaVs) by their mealybug vectors. Using plants with multiple virus infections, several virus species were screened for vector transmission by the mealybug species Planococcus ficus and Pseudococcus longispinus. We report that two GLRaVs (-4 and -9), for which no vector transmission evidence was available, are mealybug-borne. The analyses performed indicated no evidence of mealybug–GLRaV specificity; for example, different vector species transmitted GLRaV-3 and one vector species, Planococcus ficus, transmitted five GLRaVs. Based on available data, there is no compelling evidence of vector–virus specificity in the mealybug transmission of GLRaVs. However, more studies aimed at increasing the number of mealybug species tested as vectors of different GLRaVs are necessary. This is especially important given the increasing importance of grapevine leafroll disease spread by mealybugs in vineyards worldwide.

Sign in / Sign up

Export Citation Format

Share Document