Banana bract mosaic virus (BBrMV), a member of the genus Potyvirus, family Potyviridae, is the causal agent of bract mosaic disease. The disorder has been considered a serious constraint to banana and plantain production in India and the Philippines, where the virus was first identified (3). To date, the presence of BBrMV has been reported only in a few banana-growing countries in Asia (3). In the Americas, BBrMV has been detected by ELISA tests in Colombia only (1). The efficient spread of BBrMV through aphids and vegetative material increases the quarantine risk and requires strict measures to prevent entrance of the virus to new areas. In Ecuador—the world's number one banana exporter—the banana industry represents the main agricultural income source. Thus, early detection of banana pathogens is a priority. In June of 2012, mosaic symptoms in bracts and bunch distortion of ‘Cavendish’ banana were observed in a commercial field in the province of Guayas, Ecuador. Leaves from 35 symptomatic plants were tested for Cucumber mosaic virus (CMV), Banana streak virus (BSV), and BBrMV using double antibody sandwich ELISA kits from Adgen (Scotland, UK). Twenty-one plants tested positive for BBrMV but not for CMV or BSV. In order to confirm the ELISA results, fresh or lyophilized leaf extracts were used for immunocapture reverse transcription (IC-RT)-PCR. In addition, total RNA was extracted from the ELISA-positive samples and subjected to RT-PCR. The RT reactions were done using both random and oligo dT primers. Several sets of primers, flanking conserved regions of the virus coat protein (CP), have been used for PCR-detection of BBrMV (2,3,4). The Ecuadorian BBrMV isolate was successfully detected by three primer sets with reported amplification products of 324, 280, and 260 nucleotides long, respectively (3,4). Amplification products of the expected size were purified and sequenced. All the nucleotide sequences obtained from 20 PCR-positive symptomatic plants were 100% identical between each other. However, 99% identity was observed when PCR products from the Ecuadorian isolate were compared with the corresponding fragment of a BBrMV isolate from the Philippines (NCBI Accession No. DQ851496.1). PCR products of the Ecuadorian isolate, amplified by the different CP primers described above, were assembled into a 408-bp fragment and deposited in the NCBI GenBank (KC247746). Further testing confirmed the presence of BBrMV in symptomatic plants from four different provinces. To our knowledge, this is the first report of BBrMV in Ecuador and the first BBrMV partial nucleotide sequence reported from the Americas. It is worth mentioning that primer set Bract 1/Bract 2, which amplifies a 604-bp product (2), was not effective in detecting the Ecuadorian isolate. It is hypothesized that nucleotide variation at the reverse primer site is the cause of the lack of amplification with this primer set, since the forward primer is part of the sequenced product and no variation was found. Sequencing of the entire CP region is underway to conduct phylogenetic analysis and determine genetic relationships across several other BBrMV isolates. References: (1) J. J. Alarcon et al. Agron 14:65, 2006. (2) M. F. Bateson and J. L. Dale. Arch. Virol 140:515, 1995. (3) E. M. Dassanayake. Ann. Sri Lanka Dept. Agric. 3:19, 2001. (4) M. L. Iskra-Caruana et al. J. Virol. Methods 153:223, 2008.

Rice (Oryza sativa L.) is one of the leading crops and the basis of most diets in Ecuador and other countries. Diseases such as bacterial panicle blight (BPB), also known as seedling rot or grain rot, have the potential to threaten rice production worldwide. Burkholderia glumae, a causal agent of BPB, has severely affected the rice industry in many countries of Africa, Asia, and the Americas (1,2,4), but no report of this bacteria in Ecuador can be found in the literature. Rice plantations showing BPB-like symptoms including upright panicles with stained and vain grains were spotted in Palestina city, one of Ecuador's most extensive rice areas, in July 2013, but similar symptoms have been observed in the region since early 2012. Six symptomatic plants from two different groves were collected. Samples were plated on the semi-selective medium S-PG (KH2PO4 1.3 g, Na2HPO4 1.2 g, (NH4)2SO4 5 g, MgSO4·7H2O 0.25 g, Na2MoO4·2H2O 24 mg, EDTA-Fe 10 mg, L-cystine 10 μg, D-sorbitol 10 g, pheneticillin potassium 50 mg, ampicillin sodium 10 mg, cetrimide 10 mg, methyl violet 1 mg, phenol red 20 mg, agar 15 g/liter distilled water) and axenic colonies were transferred to potato dextrose agar (PDA) to test for fluorescence (3). Colonies of the potential pathogen were 1 mm, circular, entire margin, with a smooth and shiny surface. When cultured in PDA, isolates showed a moist texture, dull yellow color, and displayed fluorescence with exposure to UV light. Cells were bacterial gram-negative rods of 1 to 2 × 0.5 μm. Twelve presumptive isolates were submitted to biochemical tests (API 20NE). The biochemical profile (APIWEB) showed that all the isolates belonged to the Burkholderia genus with a 99.9% similarity. To determine the bacterial species, colonies were submitted to ELISA tests using specific antibodies for B. glumae from Agdia, Inc. The two isolates that were positive for B. glumae were sequenced using a part of the 16s rDNA amplified by the primers 536F: 5′-GTGCCAGCMGCCGCGGTAATAC-3′ and 1492R: 5′-GGTTACCTTGTTACGACTT-3′. The obtained sequences (deposited into GenBank as KF601202) shared 100% similarity with several B. glumae strains after a BLAST query. Isolates were then diluted to 108 UFC/ml and used to inoculate healthy rice plants. Inoculated plants produced BPB-like symptoms including upright panicles with stained vain grains and the bacterium was re-isolated from symptomatic plants. To the best of our knowledge, this is the first report of B. glumae in Ecuador. Further research is ongoing to identify and determine the pathogenicity of the remaining Burkholderia strains that tested negative for B. glumae. References: (1) J. Luo et al. Plant Dis. 91:1363, 2007. (2) R. Nandakumar et al. Plant Dis. 93:896, 2009. (3) T. Urakami et al. Int. J. Syst. Bacteriol. 44:235, 1994. (4) X.-G. Zhou. Plant Dis. 98:566, 2014.

Nematophagous fungi (NF) are a group of diverse fungal genera that benefit plants. The aim of this review is to increase comprehension about the importance of nematophagous fungi and their role in phosphorus solubilization to favor its uptake in agricultural ecosystems. They use different mechanisms, such as acidification in the medium, organic acids production, and the secretion of enzymes and metabolites that promote the bioavailability of phosphorus for plants. This study summarizes the processes of solubilization, in addition to the mechanisms of action and use of NF on crops, evidencing the need to include innovative alternatives for the implementation of microbial resources in management plans. In addition, it provides information to help understand the effect of NF to make phosphorus available for plants, showing how these biological means promote phosphorus uptake, thus improving productivity and yield.

Pineapple heart rot disease, caused by Phytophthora nicotianae (syn. P. parasitica), is responsible for significant annual reductions in crop yield due to plant mortality. In Ecuador, new infections arise during the rainy season and increase production costs due to the need for biocontrol and fungicide applications. Studies of P. nicotianae population structure suggest that certain genetic groups are associated with host genera; however, it is not clear how many host-specific lineages of the pathogen exist or how they are related. The objectives of this study were to determine the level of genetic variation in the P. nicotianae population causing heart rot disease of pineapple in Ecuador and compare the genotypes found on pineapple to those previously reported from citrus, tobacco and ornamentals. Thirty P. nicotianae isolates collected from infected pineapple leaves from four farms were genotyped using nine simple sequence repeat loci. In addition, the DNA sequences of mitochondrial loci cox2 + spacer and trnG-rns were analysed. Together, these loci supported a single clonal lineage with two multilocus genotypes differing in a single allele and low mitochondrial diversity. This lineage was distinct but closely related to isolates collected from vegetables and ornamentals in Italy. The results support the hypothesis of host specialization of P. nicotianae in intensive cropping systems and contribute to the understanding of population structure of this important pathogen.

In recent years, new data on the diversity of genera and species in the phylum Glomeromycota continue to be added and rearranged. Arbuscular mycorrhizal fungi are key to plant nutrition and agriculture. Studies report different short- and long-term cultivation practices that influence the abundance and diversity of Glomeromycota. To the best of our knowledge, there are no known studies of the fungal communities in the fine aroma cocoa cultivars. In this context, our work aims to discover the diversity of arbuscular mycorrhizae associated with two cocoa cultivation practices (conservative and semi-conservative) through the isolation of spores using microscopy and metabarcoding of the internal transcribed spacer region (ITS). Morphological analysis showed that the density of Glomeromycota spores exhibited significant differences between production systems. Although the metabarcoding analysis showed that diversity indices showed a higher increase in the roots than in the cocoa soil, independently of the cultivation practice. An abundance of 348 and 114 taxa were observed, corresponding to the conservative and semi-conservative practices, respectively. Seven genera were observed for the first time in cocoa crop agroforestry systems, including P. scintillans, R. diaphanus, R. fasciculatus, R. custos, D. disticha, M. perpusilla, and D. bernensis.