Correlation of genome methylation of fig tree accessions with natural nematode and rust incidence / Correlação entre a metilação genômica de acessos de figueira e a incidência natural de nematoides e ferrugem

Commercial fig tree cultivation in Brazil involves a single cultivar, 'Roxo-de-Valinhos'. The use of a single cultivar results in serious diseases and related problems. The aim of this study was to characterize fig accessions by analyzing the natural root-knot nematode and leaf rust incidence in relation to the epigenomic profile of the plant, since epigenetic variations affect plant-pathogen interactions. All plants were attacked by nematodes, indicating susceptibility; Meloidogyne incognita was the root-knot nematode species involved. Joint analysis of data showed that methylation and leaf rust incidence were correlated when observed in the same phenological phase, presenting initial evidence of the same factorial pressure loads in genotypes, suggesting similar behavior within these genotypes.

O Brasil é o maior produtor de figos da América do Sul, porém o cultivo comercial brasileiro da figueira baseia-se na plantação de uma única cultivar, o Roxo-de-Valinhos, resultando em sérios problemas relativos a pragas e doenças. Uma vez que há variações epigenéticas na interação planta-patógeno, principalmente por meio da regulação gênica, o presente trabalho objetiva realizar a caracterização in vivo de acessos de figo, por meio da análise de incidência natural de nematoides formadores de galha e de incidência natural de ferrugem, correlacionada ao seu perfil epigenômico, a fim de subsidiar trabalhos de conservação, melhoramento genético e produção da cultura. A análise dos componentes principais dos dados da caracterização dos acessos foi realizada por meio da matriz de correlação residual obtida pela análise de variância conjunta utilizando o programa GENES. Pôde-se constatar que todas as plantas foram atacadas por este patógeno, evidenciando que são suscetíveis ao mesmo. Já a análise conjunta dos dados demonstrou que a metilação e a incidência de ferrugem em folhas, quando observadas na mesma fase fenológica da planta, se correlacionam, apresentando evidências iniciais de mesmas cargas fatoriais de pressão nos genótipos, com a premissa de comportamento semelhante nos mesmos, indicando que, além do fator genético, fatores abióticos também são responsáveis pelas alterações no fenótipo das plantas, evidenciando a plasticidade fenotípica das mesmas.

Microwave Application for Controlling Oryzaephilus surinamensis Insects Infesting Dried Figs and Evaluation of Product Color Changes Using an Image Processing Technique.

In this study, microwave heating was employed for controlling Oryzaephilus surinamensis adult beetles infesting stored Iranian dried figs. The dried fig samples were artificially infested with O. surinamensis and then heated in a microwave oven (2,450 MHz) at power outputs of 450, 720, and 900 W for 20, 30, 40, and 50 s. Changes in the color of the samples after these microwave applications were evaluated for lightness (ΔL*), redness (Δa*), and yellowness (Δb*) using an image processing technique. Both parameters of microwave power and exposure time had significant effects on beetle mortality ( P < 0.01). A direct positive relationship was found between the mortality rate and microwave power. Complete mortality was achieved at 900 W and for 50 s. The color parameters of the dried fig samples did not change significantly. These results indicate that microwave irradiation can be introduced as an appropriate alternative to chemical fumigants without affecting product quality.

Níveis de infestação de Zaprionus indianus (Diptera: Drosophilidae) em diferentes frutos hospedeiros / Infestation levels of Zaprionus indianus (Diptera: Drosophilidae) in different host fruits

A mosca-do-figo, Zaprionus indianus Gupta, 1970 (Diptera: Drosophilidae) é uma espécie generalista, mas importante economicamente na cultura do figo, onde é considerada praga primária. Esse estudo teve como objetivo verificar os níveis de infestação natural de Z. indianus em frutos de amora, araçá, fisális, goiaba, mirtilo, morango e pitanga na região sul do Brasil. Os índices foram calculados por meio do número de moscas emergidas por fruto e do número de moscas por massa (kg) de fruto. Os maiores índices de infestação (mosca/kg) foram verificados em amoras (1295), araçás (1253) e pitangas (1016), enquanto que para o segundo índice (M/n) os maiores índices foram verificados em goiabas (26,17), araçás (11,87) e morangos (10,27). Frutos coletados diretamente da planta foram mais infestados em relação a frutos coletados no solo, o que pode ser devido ao ataque inicial de Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) e Anastrepha spp., pragas já disseminadas na região.

The fig fly, Zaprionus indianus Gupta, 1970 (Diptera: Drosophilidae) is a generalist species, but economically important in the fig culture, in which it is considered a primary pest. This study aimed to verify the levels of natural infestation of Z. indianus in blackberry, strawberry guava, Physalis, guava, blueberry, strawberry and Surinam cherry fruits in southern Brazil. The indexes were calculated through the number of flies emerged per fruit and the number of flies per mass (Kg) of fruit. The highest rates of infestation (fly/Kg) were observed in blackberries (1295), strawberry guavas (1253) and Surinam cherries (1016); for the second index, (M/n) in guavas (26.17), strawberry guavas (11.87) and strawberries (10.27). Fruits collected directly from the plant were more infested compared with fruits collected from the soil, which may be due to the initial attack of Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) and Anastrepha spp., pests already disseminated in the region.

Níveis de infestação de Zaprionus indianus (Diptera: Drosophilidae) em diferentes frutos hospedeiros / Infestation levels of Zaprionus indianus (Diptera: Drosophilidae) in different host fruits

A mosca-do-figo, Zaprionus indianus Gupta, 1970 (Diptera: Drosophilidae) é uma espécie generalista, mas importante economicamente na cultura do figo, onde é considerada praga primária. Esse estudo teve como objetivo verificar os níveis de infestação natural de Z. indianus em frutos de amora, araçá, fisális, goiaba, mirtilo, morango e pitanga na região sul do Brasil. Os índices foram calculados por meio do número de moscas emergidas por fruto e do número de moscas por massa (kg) de fruto. Os maiores índices de infestação (mosca/kg) foram verificados em amoras (1295), araçás (1253) e pitangas (1016), enquanto que para o segundo índice (M/n) os maiores índices foram verificados em goiabas (26,17), araçás (11,87) e morangos (10,27). Frutos coletados diretamente da planta foram mais infestados em relação a frutos coletados no solo, o que pode ser devido ao ataque inicial de Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) e Anastrepha spp., pragas já disseminadas na região.(AU)

The fig fly, Zaprionus indianus Gupta, 1970 (Diptera: Drosophilidae) is a generalist species, but economically important in the fig culture, in which it is considered a primary pest. This study aimed to verify the levels of natural infestation of Z. indianus in blackberry, strawberry guava, Physalis, guava, blueberry, strawberry and Surinam cherry fruits in southern Brazil. The indexes were calculated through the number of flies emerged per fruit and the number of flies per mass (Kg) of fruit. The highest rates of infestation (fly/Kg) were observed in blackberries (1295), strawberry guavas (1253) and Surinam cherries (1016); for the second index, (M/n) in guavas (26.17), strawberry guavas (11.87) and strawberries (10.27). Fruits collected directly from the plant were more infested compared with fruits collected from the soil, which may be due to the initial attack of Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) and Anastrepha spp., pests already disseminated in the region.(AU)

Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games?

The fig pollinating wasps (Hymenoptera: Agaonidae) have obligate arrhenotoky and a breeding structure that fits local mate competition (LMC). It has been traditionally assumed that LMC organisms adjust the sex ratio by laying a greater proportion of male eggs when there is superparasitism (several foundresses in a host). We tested the assumption with two wasp species, Pegoscapus silvestrii, pollinator of Ficus pertusa and Pegoscapus tonduzi, pollinator of Ficus eximia (= F citrifolia), in the Central Valley of Costa Rica. Total number of wasps and seeds were recorded in individual isolated naturally colonized syconia. There was a constant additive effect between the number of foundresses and the number of males produced in the brood of a syconium, while the number of females decreased. Both wasp species seem to have precise sex ratios and probably lay the male eggs first in the sequence, independently of superparasitism and clutch size: consequently, they have a non-random sex allocation. Each syconium of Ficus pertusa and of F. eximia colonized by one foundress had similar mean numbers of females, males, and seeds. The two species of wasps studied do not seem to adjust the sex ratio when there is superparasitism. Pollinating fig wasp behavior is better explained by those models not assuming that females do mathematical calculations according to other females' sex ratios, size, number of foundresses, genetic constitution, clutch size or environmental conditions inside the syconium. Our results are in agreement with the constant male number hypothesis, not with sex ratio games.

Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games?

The fig pollinating wasps (Hymenoptera: Agaonidae) have obligate arrhenotoky and a breeding structure that fits local mate competition (LMC). It has been traditionally assumed that LMC organisms adjust the sex ratio by laying a greater proportion of male eggs when there is superparasitism (several foundresses in a host). We tested the assumption with two wasp species, Pegoscapus silvestrii, pollinator of Ficus pertusa and Pegoscapus tonduzi, pollinator of Ficus eximia (= F. citrifolia), in the Central Valley of Costa Rica. Total number of wasps and seeds were recorded in individual isolated naturally colonized syconia. There was a constant additive effect between the number of foundresses and the number of males produced in the brood of a syconium, while the number of females decreased. Both wasp species seem to have precise sex ratios and probably lay the male eggs first in the sequence, independently of superparasitism and clutch size: consequently, they have a non-random sex allocation. Each syconium of Ficus pertusa and of F. eximia colonized by one foundress had similar mean numbers of females, males, and seeds. The two species of wasps studied do not seem to adjust the sex ratio when there is superparasitism. Pollinating fig wasp behavior is better explained by those models not assuming that females do mathematical calculations according to other females’ sex ratios, size, number of foundresses, genetic constitution, clutch size or environmental conditions inside the syconium. Our results are in agreement with the constant male number hypothesis, not with sex ratio games. Rev. Biol. Trop. 57 (3): 605-621. Epub 2009 September 30.

Las avispas (Hymenoptera: Agaonidae) que polinizan las inflorescencias de los higos (Moraceae: Ficus) tienen arrenotoquia obligatoria y una estructura reproductiva que calza con la de los organismos que "compiten para aparearse localmente" ("organismos LMC"). Tradicionalmente se ha supuesto que estos organismos ajustan la proporción machos: hembras ("sex ratio"), ovipositando proporcionalmente más machos cuando más de una hembra colonizadora ocupa un hospedero (e.g. un higo). Se evaluó la hipótesis con dos especies de avispas polinizadoras: Pegoscapus silvestrii, hospedero Ficus pertusa y P. tonduzi, hospedero: Ficus eximia (= F. citrifolia) en el Valle Central, Costa Rica. Se contó el número total de avispas y semillas a partir de siconos individuales, colonizados naturalmente. Ambas especies tienen una proporción fija machos:hembras y probablemente ponen los huevos macho de primero, independientemente de la cantidad de huevos que ovipositan. La postura de huevos machos y hembras no es aleatoria. Hubo un efecto aditivo constante entre el número de colonizadoras y el número de machos producidos en un siconio, mientras que el número de hembras disminuyó. Higos de F. pertusa y de F. eximia colonizados por una avispa, produjeron promedios similares de hembras, machos y semillas. Las dos especies de avispas estudiadas y probablemente otros polinizadores (especialmente aquellas que se desarrollan en especies de higos que poseen inflorescencias que son generalmente polinizadas por una avispa), no parece que posean facultades adaptativas para ajustar la proporción sexual ovipositando más huevos machos cuando hay superparasitismo (varias colonizadoras). La oviposición de las avispas de los higos se explica mejor por los modelos LMC que no suponen que las hembras conocen número, tamaño y fertilidad de otras colonizadoras, o las condiciones ambientales dentro del higo donde ovipositan. Nuestros resultados demuestran estadísticamente que cada avispa colonizadora (de las dos especies estudiadas), oviposita el mismo número de huevos macho, independientemente del superparasitismo, reconocimiento genético o el número de huevos ovipositados (o "clutch size"), de acuerdo con la hipótesis del número constante de machos. Los resultados obtenidos muestran que la selección de la relación machos: hembras en las avispas estudiadas difiere de lo creído anteriormente.

Structural and ultrastructural characterization of male reproductive tracts and spermatozoa in fig wasps of the genus Pegoscapus (Hymenoptera, Chalcidoidea).

The three Pegoscapus species present the same internal reproductive tract features comprising testes with a single testicular tubule, seminal vesicles, vasa deferentia, accessory glands and an ejaculatory duct. The seminal vesicle shows two morphologically distinct portions although they do not resemble the separate chambers found in other Chalcidoidea. The anterior portion of the seminal vesicle shows a prominent epithelium and stores the mature spermatozoa, while the posterior region is formed by a thicker muscular sheath that participates on ejaculation. The sexual maturation in Pegoscapus is achieved at emergence, when the testicular degeneration occurs. The spermatozoa of Pegoscapus reveal a basic structure similar to that of other Chalcidoidea. In Pegoscapus sp1. and Pegoscapus sp2. they present the same features, whereas Pegoscapus tonduzi comprises some different characteristics. It measures approximately 160 microm in Pegoscapus sp1. and Pegoscapus sp2., while in P. tonduzi the spermatozoa measure about 360 microm. The extracellular sheath thickness is another difference among the species. While Pegoscapus sp1. and Pegoscapus sp2. show a thick extracellular sheath, in P. tonduzi this sheath is very thin resulting in a large space intervening between the extracellular sheath and the nucleus. Despite these differences, the three species analyzed share some characteristics that allow the establishment of an identity to the spermatozoon of the genus Pegoscapus: the seminal vesicle not divided in chambers; the absence of acrosomal structures in the spermatozoa; the length of the extracellular sheath; the central microtubules being the firsts to terminate in the sequence of microtubular cutoff at the final axonemal portion.

Host-specificity and coevolution among pollinating and nonpollinating New World fig wasps.

Figs (Ficus spp., Moraceae) and their pollinating wasps (Hymenoptera, Agaonidae, Chalcidoidea) constitute a classic example of an obligate plant-pollinator mutualism, and have become an ideal system for addressing questions on coevolution, speciation, and the maintenance of mutualisms. In addition to pollinating wasps, figs host several types of nonpollinating, parasitic wasps from a diverse array of Chalcid subfamilies with varied natural histories and ecological strategies (e.g. competitors, gallers, and parasitoids). Although a few recent studies have addressed the question of codivergence between specific genera of pollinating and nonpollinating fig wasps, no study has addressed the history of divergence of a fig wasp community comprised of multiple genera of wasps associated with a large number of sympatric fig hosts. Here, we conduct phylogenetic analyses of mitochondrial DNA sequences (COI) using 411 individuals from 69 pollinating and nonpollinating fig wasp species to assess relationships within and between five genera of fig wasps (Pegoscapus, Idarnes, Heterandrium, Aepocerus, Physothorax) associated with 17 species of New World Urostigma figs from section Americana. We show that host-switching and multiple wasp species per host are ubiquitous across Neotropical nonpollinating wasp genera. In spite of these findings, cophylogenetic analyses (TREEMAP 1.0, TREEMAP 2.02beta, and parafit) reveal evidence of codivergence among fig wasps from different ecological guilds. Our findings further challenge the classical notion of strict-sense coevolution between figs and their associated wasps, and mirror conclusions from detailed molecular studies of other mutualisms that have revealed common patterns of diffuse coevolution and asymmetric specialization among the participants.

The distribution of Wolbachia in fig wasps: correlations with host phylogeny, ecology and population structure.

We surveyed for the presence and identity of Wolbachia in 44 species of chalcid wasps associated with 18 species of Panamanian figs. We used existing detailed knowledge of the population structures of the host wasps, as well as the ecological and evolutionary relationships among them, to explore the relevance of each of these factors to Wolbachia prevalence and mode of transmission. Fifty-nine per cent of these wasp species have Wolbachia infections, the highest proportion reported for any group of insects. Further, neither the presence nor the frequency of Wolbachia within hosts was correlated with the population structure of pollinator hosts. Phylogenetic analyses of wsp sequence data from 70 individuals representing 22 wasp species show that neither the close phylogenetic relationship nor close ecological association among host species is consistently linked to close phylogenetic affinities of the Wolbachia associated with them. Moreover, no genetic variation was detected within any Wolbachia strain from a given host species. Thus, the spread of Wolbachia within host species exceeds the rate of horizontal transmission among species and both exceed the rate of mutation of the wsp gene in Wolbachia. The presence and, in some cases, high frequency of Wolbachia infections within highly inbred species indicate that the Wolbachia either directly increase host fitness or are frequently horizontally transferred within these wasp species. However, the paucity of cospeciation of Wolbachia and their wasp hosts indicates that Wolbachia do not persist within a given host lineage for long time-periods relative to speciation times.