Insights into Leptocybe invasa resistance in Eucalyptus: phenotyping, genotyping and in silico approaches.

The gall wasp, Leptocybe invasa, poses a significant global threat to Eucalyptus cultivation, by causing substantial economic losses. The objective of this study was to differentiate between resistant and susceptible genotypes by morphological characteristics using image analysis based on the damage caused by the gall wasp. In addition, consensus sequences derived from transposable elements (TEs) and the genome of Eucalyptus spp. Were identified by in silico analysis. Furthermore, another objective was to discriminate Eucalyptus genotypes in response to Leptocybe invasa by conducting molecular analyses involving transposable elements and inter simple sequence markers. For image analysis, the GroundEye ® system was used to collect images of 60 leaves from six genotypes, three of which were resistant and three susceptible. Eucalyptus spp. sequences were obtained from the GenBank database by in silico analysis and pairwise alignments with TE sequences were conducted using BLASTN. Multiple sequence alignment was performed with Clustal Omega, followed by the identification of conserved regions in Jalview. A motif signature was generated using Weblogo. For molecular characterization using ISSR markers and TEs, samples of young leaves were obtained from a total of 80 Eucalyptus seedlings, of which 50 were classified as resistant and 30 as susceptible to L. invasa. It was possible to distinguish gall wasp susceptible and resistant genotypes by image analysis. In silico analysis enabled the identification of conserved regions in the Eucalyptus spp. genome, which were associated with proteins involved in secondary metabolite production, e.g., terpenes, which play a role in the response to L. invasa. The discrimination capacity of TEs and ISSR primers was demonstrated and bands were generated that could be used to identify resistant genotypes. However, increasing the number of markers required to discriminate genotypes in both cases is suggested.

Constancy, Distribution, and Frequency of Lepidoptera Defoliators of Eucalyptus grandis and Eucalyptus urophylla (Myrtaceae) in Four Brazilian Regions.

The growth of the Brazilian forest sector with monocultures favors the adaptation of Arthropoda pests. The Lepidoptera order includes major pests of Eucalyptus spp. (Myrtaceae). The aim of this work is to study the population constancy, distribution, and frequency of Lepidoptera primary pests of Eucalyptus spp. Lepidoptera pests in Eucalyptus spp. plantations were collected in Três Marias and Guanhães (state of Minas Gerais), Niquelândia (state of Goiás), and Monte Dourado (state of Pará), Brazil, for a period of 5 years, with light traps and captures, every 15 days, for every region. The number of primary pest species (12) has been similar in the four regions, and even with 1.5 to 2.4% of the total species collected, this group has shown a high frequency, especially in Três Marias, Niquelândia, and Monte Dourado, with 66.3, 54.2, and 40.0% of the individuals collected, respectively, for 5 years. The primary pest species have been constant and frequent in all the regions, with population peaks from February to September in Três Marias, February and May in Niquelândia, and from July to September in Monte Dourado. The highest population peaks of these species have been recorded when the Eucalyptus spp. plants are 3 to 6 years old. The Guanhães region is more stable and, therefore, has a lower possibility of outbreaks of the Lepidoptera primary pest species.

Primeiro registro no Brasil de Erythrina velutina Willd. como hospedeira de Tetranychus neocaledonicus (Acari: Tetranychidae) / First Brazilian report of Erythrina velutina Willd. as host of Tetranychus neocaledonicus (Acari: Tetranychidae)

Os ácaros tetraniquídeos representam importantes pragas para diversas culturas agrícolas em todo o mundo. Durante a prospecção em mudas de Erytrina velutina no distrito de São Cristovão, Estado de Sergipe, Brasil, a ocorrência destes foi observada em 15 por cento das mudas que foram levadas ao laboratório para a caracterização dos danos. As mudas apresentavam sintomas de redução e encarquilhamento do limbo. Foram coletados 100 indivíduos destas plantas, os quais foram montados em lâminas de microscopia para a identificação taxonômica. Os ácaros foram identificados como pertencentes à espécie Tetranychus neocaledonicus (Acari: Tetranychidae). Este é o primeiro relato em E. velutina, como hospedeira para T. neocaledonicus no Brasil.

Spider mites are important pests to several crops worldwide. During prospecting in Erytrina velutina specimens from São Cristovão District, Sergipe State, Brazil, their occurrence was observed in 15 percent seedlings, which were taken to the laboratory for description of damages. The seedlings presented leaf blade reduction and crumpling symptoms. One hundred mites were collected from these seedlings and mounted on microscope slides for taxonomic identification. The identified mites belonged to the species Tetranychus neocaledonicus (Acari: Tetranychidae). This is the first report of E. velutina as host for T. neocaledonicus in Brazil.

Crescimento e cultivo de diferentes isolados de pleurotus ostreatus (jacq.: fr.) kummer em serragem da casca de coco

ABSTRACT This study evaluated precocity in primordia induction and harvest initiation periods as well as the biological efficiency of heat-resistant hybrid strains of Pleurotus ostreatus using coconut-husk sawdust supplemented with wheat and/or rice bran as an alternative substrate for axenic production of edible mushrooms. The growth rate, vigor, period of primordia formation, harvest initiation period and biological efficiency of three P. ostreatus strains were evaluated in response to the supplementation of the coconut-husk sawdust based substrate with 0, 5, 20, 30 and 40% of wheat and/or rice bran. The supplementation the coconut-husk sawdust with wheat and/or rice bran reduced the C:N rate in comparison with the control group, and increased growth rate, mycelial vigor, precocity of primordia formation and the harvest period, as well as biological efficiency in all strains tested. Among the tested strains, EF60 and POSB were the most precocious in their primordia induction and harvest periods, and were also more biologically efficient than strain DF39.

RESUMO O objetivo deste trabalho foi avaliar a precocidade na indução de primórdios e no período iniciação da colheita, como também a eficiência biológica de isolados híbridos de Pleurotus ostreatus resistentes ao calor, em serragem da casca de coco suplementada com farelo de arroz e/ou de trigo, como um substrato alternativo na produção de cogumelos comestíveis, em condições axênicas. A velocidade de crescimento, o vigor, o período de formação de primórdios e da colheita e a eficiência biológica de três isolados de P. ostreatus foram avaliados em resposta à suplementação do substrato à base de serragem da casca de coco com 0, 5, 20, 30 e 40% de farelo de trigo e/ou de arroz. É importante ressaltar que a suplementação do substrato à base de serragem da casca de coco com farelos reduziu a relação C:N em relação à testemunha e favoreceu a velocidade de crescimento e o vigor micelial, a precocidade na formação de primórdios, a colheita e a eficiência biológica em todos os isolados testados. Dentre os isolados testados, EF60 e POSB destacaram-se como os mais precoces na indução de primórdios e na colheita, como também apresentaram maior eficiência biológica em comparação com o isolado DF39.

Degradação da madeira de eucalyptus sp. por basidiomicetos de podridão branca

ABSTRACT The effect of the Eucalyptus sp. degradation by basidiomycetes Pleurotus ostreatus, Pycnoporus cinnabarinus and Schizophyllum commune in vitroand in field conditions was analyzed. The trataments in vitro were: T1 control; T2 5 mL of water; T3 10 mL of water; T4 potato-dextrose-agar medium. The analyzed parameter was wood weight loss (%), after 60 and 120 days of incubation. In field conditions blocks of Eucalyptus were inoculated with spawn of Pleurotus ostreatus, Pycnoporus cinnabarinus and Schizophyllum commune. The following treatments were realized: T1 control (without water and inoculum); T2 submerged blocks for 24 h in water and T3 not submerged blocks for 24 h in water. The analyzed parameter was the wood weight loss (%), after 60 and 120 days of incubation. The degradation of Eucalyptus sp. in vitro and in field conditions was influenced by the isolate. The wood of Eucalyptus sp., in vitro, inoculated with Pycnoporus cinnabarinus had presented, on average, 25.33% weight loss and micelium was more vigorous in relation to thePleurotus ostreatus andthe Schizophyllum commune isolates. The employed treatments and the incubation period,in vitro, had not influenced the weight loss of the Eucalyptus sp. wood. In field conditions, the weight loss of wood the Eucalyptus sp. inoculated with Pycnoporus cinnabarinus was of 15.79%, already with Pleurotus ostreatus was 12.45% and Schizophyllum commune 12.95%.

RESUMO Avaliou-se a degradação de Eucalyptus sp. pelos basidiomicetos Pleurotus ostreatus, Pycnoporus cinnabarinus e Schizophyllum commune, in vitro e em condições de campo. Para tanto, na degradação in vitro foram utilizados discos de Eucalyptus sp. submetidos aos seguintes tratamentos: T1 controle; T2 5 mL de água; T3 10 mL de água; T4 meio de cultura batata-dextrose-ágar. O parâmetro analisado foi a perda de massa (em %), após 60 e 120 dias de incubação. Em condições de campo foram utilizados corpos de prova deEucalyptus sp. inoculados com substrato spawn dePleurotusostreatus, Pycnoporus cinnabarinus e Schizophyllum commune. Foram realizados os seguintes tratamentos: T1 controle (sem água e sem inóculo); T2 corpos de prova submersos por 24h em água e T3 corpos de prova não submersos por 24h em água e avaliada a perda de massa (%), após 60 e 120 dias de incubação. A degradação dos discos de eucalipto in vitro e em condições de campo foi influenciada pelos isolados. Os discos de eucalipto, in vitro, inoculados com Pycnoporus cinnabarinus apresentaram, em média, 25,33% de perda de massa e o micélio foi mais vigoroso em relação ao isolado Pleurotus ostreatus e ao Schizophyllum commune. Os tratamentos empregados e o período de incubação, in vitro, não influenciaram a perda de massa dos discos de eucalipto. Em condições de campo, a perda de massa dos corpos de prova de eucalipto, inoculados com Pycnoporus cinnabarinus, foi de 15,79%, já com Pleurotus ostreatus foi de 12,45% e Schizophyllum commune 12,95%.