Abstract Pecan [Carya illinoinensis (Wangenh.) K. Koch] is a crop fruit native to the USA and Mexico currently cultivated in several countries, including Brazil, Uruguay, Argentina, Chile, Peru, China, South Africa, and Australia. Supported by the increasing consumption and market prices, the interest in the cultivation of this fruit crop is strongly growing around the world. In this study, AFLP and S-SAP markers were employed to characterize the genetic diversity of ancient accessions of pecan from southern Brazil. The evaluated plants were selected and preserved by the farmers and are remnants of the first introduction of seedlings from the U.S.A into southern Brazil aiming at developing research towards establishing commercial orchards. High levels of genetic diversity were estimated, suggesting that these plants have an important genetic background for the establishment of a germplasm collection with a wide genetic basis, for the development of breeding programs for this fruit crop. Cluster analysis of the genetic datasets revealed some correlation between the nuts’ morphometric traits and genetic markers. Such correlation should be further exploited. These ancient genotypes must be evaluated for other agronomic traits of interest and included in core collections of pecans. Carya Wangenh. Wangenh (Wangenh. K Koch countries Uruguay Argentina Chile Peru China Africa Australia prices world study SSAP S SAP U A orchards estimated basis nuts exploited pecans (Wangenh

Resumo: O trigo mourisco é uma espécie com grande potencial econômico e de produção, a qual tem ganhado cada vez mais importância. O objetivo deste estudo foi determinar a qualidade física, fisiológica e sanitária de amostras provenientes de lotes de sementes, e avaliar a patogenicidade de Fusarium spp. em plantas de trigo mourisco. A qualidade física e fisiológica foi avaliada pelo peso de mil sementes, grau de umidade, teste de germinação (5° e 7° dias), comprimento de plântula e massa seca de plântula, enquanto que a qualidade sanitária foi determinada pelo teste de sanidade em papel filtro, com as sementes submetidas à assepsia e sem assepsia. Os isolados de Fusarium spp. foram obtidos de plântulas sintomáticas no teste de germinação em rolo de papel. Para a identificação e caracterização dos isolados fúngicos foram utilizadas abordagens morfológicas e moleculares. A patogenicidade foi realizada em plantas sadias em ambiente controlado. Os lotes apresentaram alta qualidade fisiológica na avaliação de germinação (5° e 7° dias). Houve alta incidência de Fusarium spp. em todos os lotes, a qual pode ser diminuída com a assepsia das sementes. Os isolados foram identificados como complexo de espécies de Fusarium incarnatum-equiseti, e foram patogênicos às plantas de trigo mourisco.

Abstract: Buckwheat is a species with great economic and production potential, which has gained increasing importance. This study aimed to determine the physical, physiological, and sanitary quality of samples from seed lots, and to evaluate the pathogenicity of Fusarium spp. in buckwheat plants. Physical and physiological quality was evaluated by the thousand-seed weight, moisture content, germination test (5th and 7th days), seedling length, and seedling dry mass, while sanitary quality was determined by the health test on filter paper, with the seeds subjected to asepsis and without asepsis. Isolates of Fusarium spp. were obtained from symptomatic seedlings in the paper roll germination test. To identify and characterize fungal isolates, morphological and molecular approaches were used. Pathogenicity was determined on healthy plants in a controlled environment. The lots showed high physiological quality in the germination evaluation (5th and 7th days). There was a high incidence of Fusarium spp. in all lots, which can be reduced with seed asepsis. The isolates were identified as Fusarium incarnatum-equiseti species complex, and were pathogenic to buckwheat plants.

Resumo Nas regiões Centro-Oeste e Sul do Brasil, a cultura da erva-mate (Ilex paraguariensis) constitui-se uma importante fonte de extrativismo florestal, além de diversificar a renda, principalmente na agricultura familiar. A erva-mate, como outras espécies florestais, é infectada por diversos patógenos, como o gênero Fusarium, causador da podridão-de-raízes. Os patógenos possuem ampla variabilidade genética, mesmo dentro de um único gênero e dentro de uma única espécie, resultado de adaptações ao meio em que vivem. Este estudo teve como objetivo avaliar o sequenciamento das regiões do genoma ITS e β-tubulina na identificação em nível de espécie dos isolados de Fusarium spp. patogênicos à erva-mate, e identificar a formação de grupos de compatibilidade vegetativa (VCG) entre os isolados de Fusarium spp. patogênicos à erva-mate. O sequenciamento das regiões ITS e β-tubulina consolidou a separação entre os sete isolados patogênicos em F. solani e F. oxysporum. Para esses isolados, a técnica para obtenção de mutantes nit foi adequada para a classificação fenotípica, fundamentais nos testes de VCG para espécies de Fusarium, sendo obtidos cinco VCG.

Abstract In the central-western and southern regions of Brazil, the cultivation of yerba mate (Ilex paraguariensis) is considered an important source of forest extraction, besides providing an alternative income, especially for families. The yerba mate, like other forest species, is infected by several pathogens, such as fungi of the genus Fusarium, causing root rot. Pathogens have wide genetic variability, even within a single genus and species, resulting from adaptations to their environments. This study aimed at characterizing molecularly isolated Fusarium spp. through the sequencing of the ITS and β-tubulin genome regions, identifying the species level as well as the formation of vegetative compatibility groups (VCG) among these isolates of the root rot pathogen in yerba mate. The sequencing of the ITS and β-tubulin regions, defined the separation between the seven pathogenic isolates of F. solani and F. oxysporum. For the same isolates, the technique to obtain nit mutants was suitable for the phenotypic classification, obtaining five VCGs for species of Fusarium, root rot in yerba mate.

ABSTRACT This study aims to report two species of Scolytinae that have been damaging Carya illinoinensis trees in southern Brazil. In two Brazilian municipalities, Guarapuava in Paraná State and Pantano Grande in the Rio Grande do Sul State, insects of the Scolytinae family were found damaging pecan trees. Infested tree samples were kept in the laboratory in glass tubes sealed with a voile tissue until the emergence of adults. After the adults’ emergence, the specimens were identified by their morphological characteristics and sent to a taxonomist specialized in Scolytinae family for identification. The species Xyleborus retusus was identified causing damages to pecan trees from Guarapuava while the species Xyleborus ferrugineus was identified in pecan trees from Pantano Grande. Trees injured by these insects displayed similar symptoms in both study areas. In Guarapuava and Pantano Grande, 13 and 10 trees, respectively, died due to stem lesions caused by Xyleborus spp. Thus, this study reports for Brazilian pecan growers the occurrence of Scolytinae species X. retusus and X. ferrugineus damaging C. illinoiensis plants in southern Brazil. It also emphasizes the importance of constant crop monitoring to minimize the risk of pest damage.

Abstract Brown leaf spot disease, caused by the fungus Ragnhildiana diffusa, is responsible for losses in pecan orchards and quantification is essential in order to conduct epidemiological studies to establish levels of productivity losses, and assess control strategies. Therefore, the aim of this study was to develop and validate a diagrammatic scale for assessing the severity of brown leaf spot in pecan. 240 symptomatic leaflets were collected from adult trees in Anta Gorda, in the Brazilian state of Rio Grande do Sul, and used to assess the current percentage severity of the disease. The scale was based on the minimum and maximum observed severity of the disease, with six graduations defined according to the Weber-Fechner Visual Stimulus Law. The scale therefore consisted of eight levels (1.5, 4.6, 10.6, 17.3, 39.5, 65.1, 77.5, and 98%). The estimates of eight evaluators provided a basis for validating the scale. They made estimates of disease severity on 40 symptomatic digitalized pecan leaflets first, without using the scale and then referring to it. The scale provided greater precision, accuracy, and reproducibility of estimates and should result in more reliable epidemiological studies.

Abstract Pecan cultivation in Brazil has gained increasingly economic importance in the southern part of the country. The objective of this work was to identify the pathogen that causes root rot in Carya illinoinensis seedlings in the nursery, through morphological, molecular and pathogenicity tests. Fungi from the genus Fusarium found in symptomatic roots of pecan seedlings were isolated in potato dextrose agar (PDA) culture medium and purified. Morphological characterization was performed in PDA and carnation leaf agar (CLA) media. For the molecular characterization, the genomic segments ITS (internal transcribed spaces), β-tub (beta-tubulin), and tef1-α (elongation fact 1-alpha) were sequenced. The pathogenicity test was performed on healthy seedlings in the greenhouse. The combination of morphological and molecular characters was fundamental for identification of the species, showing that the most suitable genes for identification were ITS and tef1-α. The causative agent of root rot in C. illinoinensis seedlings in the nursery was identified as Fusarium oxysporum.

RESUMO A erva-mate (Ilex paraguariensis) tem grande importância socioeconômica na agricultura familiar do Sul do Brasil. A principal doença da erva-mate é a podridão-de-raízes causada por Fusarium spp. Pouco se sabe a respeito da fisiologia deste patógeno, principalmente quanto à agressividade associada à produção de enzimas extracelulares. Neste trabalho, avaliou-se a agressividade de isolados de F. oxysporum e F. solani patogênicos à erva-mate e determinou-se as atividades das enzimas extracelulares catalase, lacase, celulase, caseinase, amilase, protease, lipase e pectinases produzidas por Fusarium spp. em meio de cultura. Foram utilizados seis isolados de F. solani e um isolado de F. oxysporum patogênicos à erva-mate. O isolado de F. oxysporum mostrou-se menos agressivo em relação aos demais isolados de F. solani. Todos os isolados de Fusarium spp. produziram, de maneira semiquantitativa, as enzimas extracelulares catalase, lacase, celulase, caseinase, amilase, protease, lipase e pectinases (poligalacturonase e pectato liase). Entretanto, a quantidade produzida de cada enzima foi significativamente diferente entre os isolados. Com exceção das enzimas lacase e poligalacturonase o isolado M7C1 de F. solani exibiu as maiores médias do índice enzimático e foi também o responsável pelo maior percentual de morte de mudas de erva-mate.

ABSTRACT The yerba-mate (Ilex paraguariensis) has great socioeconomic importance on family farming in Southerm Brazil. One of the main yerba-mate disease is root rotting, caused by Fusarium spp. Little is known about the pathogen physiology, especially regarding the aggressiveness associated with the production of extracellular enzymes. On this work, the aggressiveness of isolates of F. oxysporum and F. solani pathogenic to yerba-mate was evaluated and it was determined the activities of extracellular enzymes catalase, laccase, cellulase, caseinase, amylase, protease, lipase and pectinases produced by Fusarium spp. in culture medium. Six isolates of F. solani and one isolate of F. oxysporum pathogenic to yerba-mate were used. The F. oxysporum isolate proved to be less aggressive in relation to the other F. solani isolates. All isolates of Fusarium spp. produced, on a semiquantitative manner, the extracellular enzymes catalase, laccase, cellulase, caseinase, amylase, protease, lipase and pectinases (polygalacturonase and pectate lyase). However, the quantity produced for each enzyme was significantly different among the isolates. With the exception of the laccase and polygalacturonase enzymes, the M7C1 isolate showed the highest enzymatic index and was also responsible for the highest percentage of yerba-mate seedlings death.

ABSTRACT The cultivation of yerba-mate (Ilex paraguariensis) has been intensified in the State of Rio Grande do Sul, as result of the valuation of the price paid to the producer. However, studies related to Fusarium pathosystem vs. yerba-mate are still insufficient, so that many producers have faced significant losses in herbal production due to the occurrence of the roots rotting. Considering the above, the objectives of this study were: a) morphologically characterize the Fusarium spp. isolates collected in sick plants of yerba-mate; b) select efficient morphological characters on separating the Fusarium spp. isolates in similarity groups; c) identify the Fusarium spp. isolates to species level through the sequencing of the genomic region of elongation factor 1-α (TEF-1α); and d) testing the pathogenicity of the Fusarium spp. isolates selected based on the morphological characterization. For such, collections for the pathogen isolates were made in five cities and the collection points were georeferenced. Thirty-nine isolates were morphologically characterized by variables as mycelial growth, sporulation, macroconidia length and width, microconid format, colonies pigmentation and formation of chlamydospore, and tested for pathogenicity by substrate inoculation. The variables used in the morphological characterization were efficient in discriminating the isolates in seven groups, especially length of macronidia associated to sporulation. Seven pathogenic isolates of Fusarium spp. were identified, also through molecular sequencing of the TEF-1α gene region. The sequencing of the TEF-1α region consolidated the identification of pathogenic isolates as F. solani and F. oxysporum.

RESUMO: Neste trabalho, objetivou-se avaliar a eficiência dos métodos de superação de dormência de sementes, em diferentes períodos de armazenamento, na produção de mudas de nogueira-pecã. As sementes foram submetidas aos seguintes tratamentos: T1, T4 e T7 - testemunhas (sementes sem qualquer método de tratamento, armazenadas em ambiente não controlado por 30, 60 e 90 dias, respectivamente), T2, T5 e T8 - estratificação (sementes distribuídas em caixas com areia úmida e mantidas em temperatura de 4°C por 30, 60 e 90 dias, respectivamente), T3, T6 e T9 - escarificação + estratificação (sementes escarificadas com lixa n.80 e estratificadas também por 30, 60 e 90 dias, respectivamente), em delineamento experimental inteiramente ao acaso. Avaliou-se, após 14 semanas da semeadura, altura das plantas, diâmetro do colo, número de folhas, emergência total e índice de velocidade de emergência (IVE). O melhor desenvolvimento das plantas de nogueira-pecã, bem como sua emergência e IVE foi observado no tratamento com estratificação por 90 dias e quando combinado escarificação e estratificação por 90 dias. O armazenamento das sementes em ambiente não controlado reduz sua viabilidade.

ABSTRACT: This study evaluated the efficiency of methods to overcome seed dormancy in different storage periods in the production of pecan seedlings. Seeds were submitted to the following treatments: T1, T4 and T7 - control treatments (seeds with no treatment, stored at room temperature for 30, 60 and 90 days, respectively), T2, T5 and T8 - stratification (seeds were distributed in boxes with wet sand maintained at a temperature of 4°C for 30, 60 and 90 days, respectively), T3, T6 and T9 - scarification + stratification (seeds scarified with sandpaper n.80 and stratified by 30, 60 and 90 days, respectively), in completely random experimental design. Plant height, stem diameter, number of leaves, full emergence and emergence speed index (ESI) were evaluated after 14 weeks of sowing. The best development of pecan 'plants, their emergence, and ESI were observed in the stratification treatment for 90 day as well as in the scarification + stratification treatment for 90 day. Storing seeds in uncontrolled environment reduced their viability.

A cultura da nogueira-pecã tem grande importância para a economia de vários municípios do Sul do Brasil. Entretanto, problemas como baixa porcentagem de germinação das sementes e irregularidade na emergência das plântulas trazem dificuldades no processo de propagação, decorrentes da influência do fenômeno da dormência. O objetivo deste trabalho foi avaliar diferentes técnicas de superação da dormência de sementes de nogueira-pecã e o posterior desenvolvimento das plântulas. Para tanto, foram testados quatro diferentes métodos de superação de dormência, em que, nos tratamentos testemunhas, as sementes permaneceram em ambiente protegido sem qualquer tratamento; no método com escarificação, as sementes foram lixadas na parte apical no momento da semeadura e na estratificação, acomodadas em caixas com areia úmida e mantidas na temperatura de 4 ºC. Também foi testada a combinação escarificação e estratificação, simultaneamente. Os tratamentos foram compostos por 10 repetições de três sementes cada. Após cada período (30, 60 e 90 dias), as sementes foram semeadas em bandeja contendo substrato Mecplant® e mantidas a 25 ºC ± 2 ºC, sob fotoperíodo de 12 h. Avaliaram-se a altura da parte aérea, o diâmetro do colo, o número de folhas, a emergência total, o índice de velocidade de emergência, a biomassa seca, a área foliar e o comprimento da raiz pivotante. O melhor desenvolvimento de plântulas de nogueira-pecã, bem como sua emergência, foi observado no tratamento com estratificação por 90 dias e, quando combinadas escarificação mais estratificação, por 90 dias.

ABSTRACT Pecan culture is very important for the economy of a large number of towns in Southern Brazil. However, problems such as low percentage of germination and irregularity in seedling emergence hamper the process of propagation, resulting from the influence of the dormancy phenomenon. The objective of this study was to evaluate different techniques to overcome the dormancy of pecan seeds and the subsequent development of seedlings testing four different methods. In the control treatments, the seeds remained in a protected environment with no treatment. In the method with scarification, seeds were sanded in the apical part at the time of sowing and stratification. Then, seeds were accommodated in boxes with moist sand and subsequently kept at 4 °C. Additionally, scarification and stratification methods were tested simultaneously. Treatments consisted of 10 repetitions of three seeds each. After each period (30, 60 and 90 days), seeds were sown in trays containing Mecplant® substrate and maintained at 25 °C ± 2 °C, photoperiod of 12 h. Shoot height, stem diameter, number of leaves, total emergency, emergency speed index, dry biomass, leaf area and length of the taproot were evaluated. The best development of pecan seedlings and their emergence were observed in the stratification treatment for 90 days as well as when scarification was used in combination with stratification for 90 days.

Resumo: O objetivo deste trabalho foi avaliar o efeito da estratificação de sementes na taxa de germinação, na velocidade de germinação e no desenvolvimento inicial de mudas de seis cultivares de nogueira-pecã (Carya illinoinensis) sob condições climáticas subtropicais, no Sul do Brasil. Para estratificação, as sementes foram acomodadas em caixas com areia úmida, em câmara fria a 4°C, por 90 dias. Na décima quarta semana após o plantio, foram avaliados o índice de velocidade de emergência, a emergência total, a altura da planta, o diâmetro do caule e o número de folhas. A estratificação das sementes melhora significativamente o potencial de germinação e as características morfológicas das cultivares avaliadas.

Abstract: The objective of this work was to evaluate the effect of seed stratification on germination rate, germination speed, and initial development of seedlings of six pecan (Carya illinoinensis) cultivars under subtropical climatic conditions in southern Brazil. For stratification, the seeds were placed in boxes with moist sand, in a cold chamber at 4°C, for 90 days. In the fourteenth week after sowing, the emergence speed index, total emergence, plant height, stem diameter, and number of leaves were evaluated. Seed stratification significantly improves the germination potential and morphological traits of the evaluated cultivars.

A podridão-de-raízes da erva-mate, causada por Fusarium spp., Rhizoctonia sp. e Pythium sp., é a principal doença da cultura e causa sérios prejuízos em viveiro e a campo. No entanto, existem poucos estudos referentes à epidemiologia dessa doença. Assim, o presente trabalho teve por objetivo estudar e descrever os principais aspectos epidemiológicos relacionados à podridão-de-raízes da erva-mate em viveiro e a campo. Para isso, foram demarcados para estudo ervais e viveiros localizados na região alta do Vale do Taquari - RS, nos quais se procedeu a coleta de flores, frutos, sementes, plântulas, mudas e substrato para análises laboratoriais. Observou-se que as flores podem ser a porta de entrada dos patógenos no patossistema, pois 80% delas apresentaram contaminação por Fusarium sp. e 15% por Rhizoctonia sp. Além disso, o método de obtenção e estratificação das sementes, utilizado pelos viveiristas, contribuem para o aumento da contaminação, chegando a 100% das sementes no momento da semeadura. Observou-se, também, que as mudas podem estar contaminadas, mesmo não apresentando sintomas e, ao serem replantadas a campo, venham a contaminar áreas livres dos patógenos. Os testes de patogenicidade com alguns isolados mostraram sua capacidade em causar a doença.

The root-rot of erva-mate, caused for Fusarium spp., Rhizoctonia sp. and Pythium sp., is the main disease of the culture and causes serious damages in nurseries and forest stands. However, few studies exist regarding to the epidemiology of this disease. Thus, the present work studied and described the main epidemic aspects related to erva-mate root-rot in nurseries and forest stands. For that, nurseries and forest stands were chosen for studies in Vale do Taquari, RS state, where flowers, fruits, seeds, plantlets, seedlings and soil were collected for laboratory analyses. It was observed that the pathogens can enter in the patho-system through the flowers, because 80% of them presented contamination of Fusarium sp. and 15% of Rhizoctonia sp. Moreover, the obtaining method and stratification of the seeds, used in the nurseries, contribute to the increase of contamination, reaching 100% of the seeds in the moment of sowing. It was also observed that contaminated seedlings may be symptomless and, after transplanting in the field, contaminate pathogen free areas. Pathogenicity tests with some isolates showed their capacity of causing the disease.

O objetivo deste trabalho foi determinar o tamanho de amostra necessário para a estimação da média das massas do fruto, da casca e da amêndoa e dos diâmetros longitudinal e transversal de frutos de nogueira-pecã ( Carya illinoinensis). Em 20 frutos, de cada uma de seis cultivares de nogueira-pecã ('Barton', 'Imperial', 'Importada', 'Mahan', 'Moneymaker' e 'Melhorada'), foi determinada a massa do fruto (MF), a massa da casca (MC) e a massa da amêndoa (MA) e mensurado o diâmetro longitudinal (DL) e o diâmetro transversal (DT). Com os dados desses 20 frutos, para cada caractere e cultivar, foram calculadas medidas de tendência central e de variabilidade, verificada a normalidade e calculado o tamanho de amostra. Para cada caractere, foi verificada a homogeneidade de variâncias entre as cultivares e comparadas as médias de cultivares. Cinquenta frutos são suficientes para a estimação da média de MF, MC, MA, DL e DT de frutos de nogueira-pecã, para erro de estimação de até 5% da média estimada, com grau de confiança de 95%.

The objective of this research was to determine the sample size necessary to estimate the average mass of fruit, peel and almond and longitudinal and transverse diameters of fruits of pecan ( Carya illinoinensis). On 20 fruits of each of the six cultivars of pecan ('Barton', 'Imperial', 'Importada', 'Mahan', 'Moneymaker' e 'Melhorada'), the fruit mass (MF), the shell mass (MC) and almond mass (MA) was determined and measured the longitudinal diameter (DL) and transverse diameter (DT). With the data from these 20 fruits for each character and cultivar, measures of central tendency and variability were calculated, normality was checked and sample size was calculated. For each character, the homogeneity of variances among cultivars was verified and averages of cultivars were compared. Fifty fruits were enough to predict the average of MF, MC, MA, DL and DT fruit of pecan, with an estimation error equal to 5% of estimated average, with a degree confidence of 95%.

O objetivo deste trabalho foi determinar o tamanho de amostra (número de plantas) necessário para a estimação da média de altura de planta, do diâmetro do coleto e da relação altura de planta/diâmetro do coleto de mudas de nogueira-pecã (Carya illinoinensis) e verificar a variabilidade do tamanho de amostra entre tratamentos de superação de dormência de sementes. Foram avaliados 12 tratamentos de superação de dormência de sementes e, aos 98 dias após a semeadura, foram mensurados os caracteres altura de planta (H) e diâmetro do coleto (D), e calculada a relação altura de planta/diâmetro do coleto (HD). Foram calculadas medidas de tendência central e de variabilidade, verificadas a normalidade e a homogeneidade de variâncias e calculado o tamanho de amostra. O tamanho de amostra para avaliar H, D e HD de mudas de nogueira-pecã é dependente do tratamento para superação de dormência de sementes. Sessenta e três plantas são suficientes para a estimação da média de H, do D e da HD de mudas de nogueira-pecã, para erro de estimação de 10% da média estimada, com grau de confiança de 95%

The aim of this research was to determine the sample size (number of plants) necessary to estimate the average plant height, collar diameter and relation plant height/collar diameter of seedlings pecan (Carya illinoinensis) and to verify the variability of the sample size among treatments of overcoming seed dormancy. It was evaluated 12 treatments of overcoming seed dormancy and at 98 days after sowing it was measured the plant height (H) and collar diameter (D) and calculated the relation plant height/collar diameter (HD). Measures of central tendency and variability were calculated, the normality and homogeneity of variances were verified and sample size was calculated. The sample size to evaluate H, D e HD is dependent on treatments of overcoming seed dormancy. Sixty-three plants enough to predict the average of H, D and HD seedlings pecan, with an estimation error equal to 10% of estimated average, with a degree confidence of 95%