Genome-wide SNP analysis to assess the genetic population structure and diversity of Acrocomia species.

Acrocomia (Arecaceae) is a genus widely distributed in tropical and subtropical America that has been achieving economic interest due to the great potential of oil production of some of its species. In particular A. aculeata, due to its vocation to supply oil with the same productive capacity as the oil palm (Elaeis guineenses) even in areas with water deficit. Although eight species are recognized in the genus, the taxonomic classification based on morphology and geographic distribution is still controversial. Knowledge about the genetic diversity and population structure of the species is limited, which has limited the understanding of the genetic relationships and the orientation of management, conservation, and genetic improvement activities of species of the genus. In the present study, we analyzed the genomic diversity and population structure of Acrocomia genus, including 172 samples from seven species, with a focus on A. aculeata with 117 samples covering a wide geographical area of occurrence of the species, using Single Nucleotide Polymorphism (SNP) markers originated from Genotyping By Sequencing (GBS).The genetic structure of the Acrocomia species were partially congruent with the current taxonomic classification based on morphological characters, recovering the separation of the species A. aculeata, A. totai, A. crispa and A. intumescens as distinct taxonomic groups. However, the species A. media was attributed to the cluster of A. aculeata while A. hassleri and A. glauscescens were grouped together with A. totai. The species that showed the highest and lowest genetic diversity were A. totai and A. media, respectively. When analyzed separately, the species A. aculeata showed a strong genetic structure, forming two genetic groups, the first represented mainly by genotypes from Brazil and the second by accessions from Central and North American countries. Greater genetic diversity was found in Brazil when compared to the other countries. Our results on the genetic diversity of the genus are unprecedented, as is also establishes new insights on the genomic relationships between Acrocomia species. It is also the first study to provide a more global view of the genomic diversity of A. aculeata. We also highlight the applicability of genomic data as a reference for future studies on genetic diversity, taxonomy, evolution and phylogeny of the Acrocomia genus, as well as to support strategies for the conservation, exploration and breeding of Acrocomia species and in particular A. aculeata.

Survey of aphid population in a yellow passion fruit crop and its relationship on the spread Cowpea aphid-borne mosaic virus in a subtropical region of Brazil.

BACKGROUND: Passion fruit woodiness may be caused by Cowpea aphid-borne mosaic virus (CABMV) and is currently the major passion fruit disease in Brazil. To assess the virus-vector-host interactions, a newly introduced golden passion fruit plantation located in eastern region of São Paulo State, Brazil, was monitored. METHODS: Dissemination of CABMV was determined analyzing golden passion fruit plants monthly for 18 months by PTA-ELISA. Seasonality and aphid fauna diversity was determined by identification of the captured species using yellow sticky, yellow water-pan and green tile traps. Population composition of the aphid species was determined using the descriptive index of occurrence, dominance and general classification and overlap of species in the R program. RESULTS: Analyses of species grouping afforded to recognize 14 aphid species. The genus Aphis represented 55.42 % of the species captured. Aphid species formed two distinct clusters, one of which was characterized by the diversity of polyphagous species that presented high potential to spread CABMV. CONCLUSION: The low abundance and diversity of aphid species did not interfere negatively in the CABMV epidemiology. The genus Aphis, particularly Aphis fabae/solanella and A. gossypii, was crucial in the spread of CABMV in passion fruit orchards in the eastern State of São Paulo.

The genetic structure and mating system of Acrocomia aculeata (Arecaceae).

Acrocomia aculeata is a perennial, fruit-producing palm tree, native to tropical forests. Its fruits have spurred interest because of their significant potential for use in the cosmetic industry and as feedstock for biofuel. In the present study, the genetic structure and mating system in Acrocomia aculeata were analyzed, using eight nuclear micro-satellite loci and samples from São Paulo and Minas Gerais states, Brazil. By means of Bayesian analysis, these populations were clustered into two or three groups. A high multilocus outcrossing rate suggests that outcrosses were predominant, although a certain degree of biparental inbreeding also occurred. Thus, although monoecious and self-compatible, there is every indication that A. aculeata bears a mixed reproductive system, with a predominance of outcrossing. Given the genetic structure revealed hereby, future conservation strategies and germplasm collecting should be focussed on sampling and preserving individuals from different clusters.

The genetic structure and mating system of Acrocomia aculeata (Arecaceae)

Acrocomia aculeata is a perennial, fruit-producing palm tree, native to tropical forests. Its fruits have spurred interest because of their significant potential for use in the cosmetic industry and as feedstock for biofuel. In the present study, the genetic structure and mating system in Acrocomia aculeata were analyzed, using eight nuclear microsatellite loci and samples from São Paulo and Minas Gerais states, Brazil. By means of Bayesian analysis, these populations were clustered into two or three groups. A high multilocus outcrossing rate suggests that outcrosses were predominant, although a certain degree of biparental inbreeding also occurred. Thus, although monoecious and self-compatible, there is every indication that A. aculeata bears a mixed reproductive system, with a predominance of outcrossing. Given the genetic structure revealed hereby, future conservation strategies and germplasm collecting should be focussed on sampling and preserving individuals from different clusters.

Susceptibility of guava genotypes to natural infestation by Anastrepha spp. (Diptera: Tephritidae) in the municipality of Monte Alegre do Sul, state of São Paulo, Brazil

As espécies infestantes de moscas-das-frutas e seus índices de infestação foram determinados para onze genótipos de goiaba (Psidium guajava L.). De março a abril de 2000, dez frutos maduros de cada genótipo foram coletados em intervalos semanais, de plantas não pulverizadas com inseticidas, instaladas no município de Monte Alegre do Sul, SP. Os frutos foram trazidos para o laboratório, pesados e colocados em copos plásticos contendo areia para obtenção de pupas de tefritídeos. De 95% das goiabas coletadas foram obtidos pupários de moscas-das-frutas. Das 682 fêmeas de Anastrepha recuperadas, quatro espécies foram identificadas: A. fraterculus (Wied.) (86,5%), A. obliqua (Macquart) (10,8%), A. bistrigata Bezzi (1,8%) e A. sororcula Zucchi (0,9%). Três espécies de parasitóides Braconidae (Opiinae) foram recuperadas: Doryctobracon areolatus (Szépligeti), Doryctobracon brasiliensis (Szépligeti) e Utetes anastrephae (Viereck). Os genótipos diferiram quanto aos níveis de infestação dependendo da época da coleta. Os genótipos 'L2P4 Vermelha', 'Ruby Suppreme' e 'Webber Suppreme' mostraram menor susceptibilidade em termos de produção de pupários por fruto. A variabilidade de infestação entre os genótipos de goiaba e as razões do aumento no nível de infestação ao longo do tempo são discutidas.

Caracterização Morfológica de Três Espécies de Broca-da-Haste em Chuchuzeiro (Coleoptera: Cerambycidae, Lamiinae) / Morphological Characterization of Three Species of Stem Borer (Coleoptera: Cerambycidae, Lamiinae) in Chayote

The simultaneous occurrence of Adetus analis (Haldeman), Adetus fuscoapicalis Breuning and Plerodia syrinx (Bates) (Coleoptera: Cerambycidae, Lamiinae) is reported boring the stems of chayote, Sechium edule. A. analis is the same species as Adetus muticus (Thomson) been wich was referred before by several authors in Brazil. A. analis and A. fuscoapicalis are similar in morphologic and ethologic aspects. This paper presents a detailed description and illustrations of both species in order to help in the identification of these species. P. syrinx, which shows the same attacking behavior of these species of Adetus, also had its morphological characters described, in pupal and adult stages.

A ocorrência simultânea de Adetus analis (Haldeman), Adetus fuscoapicalis Breuning e Plerodia syrinx (Bates) (Coleoptera: Cerambycidae, Lamiinae), broqueando ramos de chuchuzeiro Sechium edule (Jaqc.) Sw., é relatada. A. analis é sinônima de A. muticus (Thomson), que foi referida por diversos autores no Brasil. A. analis e A. fuscoapicalis são muito semelhantes quanto aos aspectos morfológicos e etológicos. Assim foi realizada uma descrição detalhada e ilustrações de ambas espécies a fim de promover uma identificação segura. P. syrinx, que apresenta comportamento de ataque semelhante ao das espécies de Adetus, também foi descrita em seus caracteres morfológicos nas fases de pupa e adulto.