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Over the last few years, considerable effort has been spent by Embrapa in the construction of a plant disease database representative enough for the development of effective methods for automatic plant disease detection and recognition. In October of 2016, this database, called PDDB, had 2326 images of 171 diseases and other disorders affecting 21 plant species. PDDB size, although considerable, is not enough to allow the use of powerful techniques such as deep learning. In order to increase its size, each image was subdivided according to certain criteria, increasing the number of images to 46,513. Both the original (PDDB) and subdivided (XDB) databases are now being made freely available for academic research purposes, thus supporting new studies and contributing to speed up the advances in the area. Both collections are expected to grow continuously in order to expand their reach. PDDB and XDB can be accessed in the link https://www.digipathos-rep.cnptia.embrapa.br/. more...

Cotton blue disease (CBD) is the viral disease which poses the greatest threat to cotton in Brazil. One efficient way of controlling this disease is by using resistant cultivars. However, the recent emergence of an atypical form of CBD (ACBD), caused by a new virus genotype capable of overcoming these resistant cultivars, is causing concern. Thus, the aims of this study were to evaluate the distribution of ACBD in the states of Mato Grosso (MT) and Goias (GO), to determine the relationship between vector infestation level, disease incidence and yield, and to check the reaction of cotton cultivars to two viral isolates. In both cotton production areas, 1128 plots were surveyed and 6.5% showed plants with the virus, 97.3% and 2.7% with ACBD and CBD, respectively. In cultivars susceptible to ACBD, a positive linear relationship between changes in the levels of aphid infestation and incidence of viral infection was indentified, and a negative linear relationship between infestation level and yield. The maximum acceptable level of aphids up to 80 days after sowing for susceptible cultivars was approximately 15%. Although 83% of the cultivars were shown to be resistant to CBD, only 19.2% were resistant to ACBD. There was also a number of cultivars with considerable resistance to both isolates. more...

BRS 369RF and BRS 370RF were developed by the EMBRAPA as a part of efforts to create high-yielding germplasm with combinations of transgenic traits. BRS 369RF and BRS 370RF are midseason cultivars and have yield stability, adaptation to the central Brazilian savanna, good fiber quality and tolerance to glyphosate herbicide. more...

Dentre as doenças que incidem sobre o algodoeiro, o "tombamento" é considerado uma das principais, sendo causado por um complexo de fungos de solo e da semente, os quais, ocorrendo separadamente ou em combinação, podem ocasionar o tombamento de pré e pós-emergência das plântulas. Os principais agentes etiológicos do tombamento são Rhizoctonia solani Khun, Colletotrichum gossypii South e Colletotrichum gossypii South var. cephalosporioides Costa. O objetivo deste trabalho foi avaliar o efeito de diversos fungicidas, utilizados em tratamento de sementes de algodão, no controle de patógenos associados às sementes e/ou presentes no solo. Sementes livres de patógenos, não-inoculadas e inoculadas com Colletotrichum gossypii var. cephalosporioides(Cgc)), foram tratadas com tolylfluanid + pencycuron + triadimenol, carboxin + thiram e fluazinam + tiofanato metílico. No teste de emergência em areia, o tratamento testemunha inoculada com Cgc apresentou o menor índice de emergência. O maior índice de emergência ocorreu em sementes sem inoculação e tratadas com tolylfluanid + pencycuron + triadimenol. O tratamento mais eficiente no controle do tombamento de pós-emergência do algodoeiro, em substratos contendo Rhizoctonia solani, foi a mistura tolylfluanid + pencycuron + triadimenol. No campo, a maior incidência e severidade da ramulose, causada por Cgc, ocorreu em plantas provenientes de sementes não tratadas com fungicidas e inoculadas com Cgc. Nenhum dos fungicidas testados foi fitotóxico ao algodão. The cotton seedling damping-off is a worldwide problem caused by a complex of soil-borne and seed-borne fungi, occurring separately or in combination, and cause pre- or post-emergence damping-off. The main etiological agents causing the damping-off are Rhizoctonia solani Khun, Colletotrichum gossypii South and Colletotrichum gossypii var. cephalosporioides. The aim of this work was to evaluate the effectiveness of many fungicides that have been used on the treatment of cottonseeds to control pathogens associated with seeds and/or presents in the soil. Cottonseeds free of pathogens, inoculated and non-inoculated with Colletotrichum gossypii var. cephalosporioides (Cgc), were treated with tolylfluanid + pencycuron + triadimenol; carboxin + thiram and fluazinam + thiophanate methyl. On the Growing on Test, the non-treated seeds inoculated with Cgc showed a lower level of emergence. The higher level of emergence occurred on non-inoculated seeds treated with tolylfluanid + pencycuron + triadimenol. The most efficient treatment in the control of post-emergence damping-off in substrates containing Rhizoctonia solani, was obtained with the mixture of tolylfluanid + pencycuron + triadimenol, followed by carboxin + thiram. In the field, the higher severity of ramulosis, caused by Cgc, occurred in plants from non-treated seeds inocculated with Cgc. None of the fungicides tested showed phytotoxity to cotton. more...

Cotton cultivar BRS 335 is a midseason high-yield cultivar and has adaptation to the Northeast Brazilian savanna, yield stability, desirable resistance to main cotton diseases and good fiber quality. The cultivar BRS 335 meets growers? demands for competitive lint yield as well as fulfilling industrial textile requirements. Made available in DSpace on 2021-11-12T12:00:45Z (GMT). No. of bitstreams: 1 BRS-335.pdf: 288519 bytes, checksum: 9deb571e7e679b3288a49028a7a0cc19 (MD5) Previous issue date: 2012 more...

Flow cytometric analysis of immuno-stained cells (immuno-FCM) was compared to immunofluorescence microscopy (IF) and dilution plating on a semi-selective medium, for quantitative detection of Xanthomonas axonopodis pv. phaseoli (Xap) in bean seed extracts. Cell concentrations of Xap between 103-107 CFU/mL were added to healthy bean seed extracts. A flow cytometry sorting procedure was developed to separate immuno-stained Xap cells from crude seed extracts and confirming by PCR. FCM was evaluated for direct viable counting (DVC) of Xap using combinations of propidium iodide (PI) and carboxy fluorescein diacetate (cFDA) or PI and SYTO 9 and also the combination of immuno-FCM and PI. Dilution plating and IF allowed detection of Xap in bean seed extracts in a range of 103-106 CFU/mL and immuno-FCM from 104-106 CFU/mL. Sorted cells could be detected in crude seed extracts by PCR without further extraction. FCM also allowed quantification of viable cells of Xap after DVC procedures; the red fluorescent dye propidium iodide was used to identify dead cells in combination with the green fluorescent dyes cFDA or SYTO 9, these identifying live cells. The combination of immuno-FCM and PI could be more promising and reliable to detect this pathogen in seeds. Key words: seed pathology, flow sorting, PCR-amplification, viability probes, immunofluorescence, bacteria. more...

A primeira fase do trabalho objetivou avaliar o efeito do tempo de deslintamento químico, 1:30 e 4:30 min, sobre o nível de infecção de Colletotrichum gossypii inoculado artificialmente em sementes de algodoeiro (Gossypium hirsutum). Sementes de algodoeiro com línter foram inoculadas com C. gossypii, mediante contato das mesmas com colônias do fungo em placas de Petri de 9 cm de diâmetro, por 30 h. Os parâmetros avaliados foram a ocorrência de fungos e o poder germinativo das sementes. Na segunda fase, o objetivo foi avaliar a influência do exsudato de sementes de algodoeiro, em função do tempo da duração do deslintamento com ácido sulfúrico, considerando-se as frações de sedimentação de sementes e diferentes condições de envelhecimento artificial sobre o desenvolvimento de C. gossypii, em condições de laboratório. As sementes foram deslintadas quimicamente com ácido sulfúrico comercial concentrado pelos períodos de 1:30 e 4:30 min, separadas em frações de sedimentação em água e submetidas ao envelhecimento artificial por 0, 72 e 96 h. Os substratos foram obtidos a partir do exsudato resultante da embebição contendo os eletrólitos lixiviados das sementes. O desenvolvimento de C. gossypii na presença do exsudato das sementes foi avaliado em meio agarizado, através da medição do crescimento micelial e da esporulação do fungo. O deslintamento químico, pelo período de 1:30 min, propiciou aumento do percentual de ocorrência de C. gossypii em sementes não-desinfestadas superficialmente, e o crescimento micelial e a esporulação do fungo foram favorecidos pelo substrato proveniente de sementes deslintadas por 4:30 e 1:30 min, respectivamente. more...

The current world production of cotton is approximately 25.10 million tons and it has being produced by more than 60 countries on five continents. Among the major world producers, China, India, United States, Brazil and Pakistan stand out (United States Department of Agriculture USDA, 2012). The expansion of areas under cultivation, the monoculture cropping system and especially the use of susceptible cultivars cause a significant increase in the inoculum potential of various pathogens, consequently causing a higher incidence of diseases. more...

The objective of this work was to determine the inheritance of cotton blue disease resistance by cotton plants. Populations derived from the CD 401 and Delta Opal resistant varieties were evaluated, through a greenhouse test with artificial inoculation by viruliferous aphids. Cotton blue disease resistance is conditioned by one dominant gene, both in CD 401 and Delta Opal varieties. O objetivo deste trabalho foi determinar a herança da resistência do algodoeiro à doença-azul. Populações derivadas das variedades resistentes CD 401 e Delta Opal foram avaliadas em casa de vegetação, por meio da inoculação de pulgões virulíferos. A resistência à doença-azul do algodoeiro é condicionada por um gene dominante, tanto em 'DC 401' quanto em 'Delta Opal'. more...

The objective of this work was to evaluate the efficiency of delinting time of cottonseeds through the electrical conductivity and the quantity of neutral sugars and uronic acids leaked from the seeds during imbibition in water, in function of the fractioning in water and the artificial ageing. The seeds were delinted with commercial sulphuric acid for 1.5 and 4.5 minutes, separeted according to the sedimentation fractions in water and submitted to artificial ageing for 0, 72 and 96 hours. Electrical conductivity, contents of neutral sugars and uronic acids were determinated from the exudate resulting from the seeds imbibition in relation different treatments. The results showed that the delinting time for 1.5 minutes provided higher values of electrical conductivity, higher contents of neutral sugars and lower contents of uronic acids in relation with delinted seeds. more...

Cotton (Gossypium hirsutum L.) is the most important natural textile fiber in the world. It is cultivated mainly to obtain fibers, although it also stands out as a source of oil and food products. In Brazil, since the early 1990s, the main cotton-growing area is located in the Brazilian tropical savannah (Morello et al. 2020). Due to a well-defined rain season, most cotton fields are rainfed and the lint yield is often very high, an average of 1672.94 kg ha-1 in the 2018-2019 growing season (ABRAPA 2020). In 2019, Brazil was the second largest cotton fiber exporter and fourth largest cotton fiber producer in the world (OECD-FAO 2020). However, the production system is based on extensive areas requiring several pesticide applications to achieve high levels of fiber production. In this scenario, Ramularia leaf spot disease (RLS), caused by Ramulariopsis pseudoglycines (teleomorph: Mycosphaerella areola), became epidemic, with considerable economic impact (Silva et al. 2019a). Additionally, the root-knot nematode (RKN), Meloidogyne incognita, is an emerging threat in cotton-growing regions (Belot et al. 2020). Recently, sources of resistance to RLS have been identified and efforts have been made to develop cultivars tolerant or resistant to RLS (Silva et al. 2019a, Suassuna et al. 2020). Sources of resistance to RKN are available (Lopes et al. 2020), and the stocks most used for resistance are sourced from Auburn 623 RNR (Shepherd 1974). The high resistance in Auburn 623 RNR has been RNR (Shepherd 1974). The high resistance in Auburn 623 RNR has been transferred to breeding lines (M-lines). Genetic resistance in M-lines is under oligogenic inheritance, determined by two QTLs located on chromosomes 11 and 14. The QTL (qMi-C11), located on chromosome 11, has a dominant effect on gall formation, whereas the QTL (qMi-C14), located on chromosome 14, has a partial dominant effect and is associated with reduced egg production (Silva et al. 2019b). Resistance (near-immunity) to the RKN is conferred by an epistatic interaction between the two QTLs (Gutiérrez et al. 2010, Lopes et al. 2020). A cotton-breeding program was established by Embrapa in the 1980s to develop cultivars adapted to the cerrado (Brazilian tropical savanna) environment focusing on high-quality fiber (Morello et al. 2020) or enhanced disease resistance (Suassuna et al. 2020). Here, we report the development of the transgenic cotton cultivar BRS 500 B2RF, with resistance to RLS and partial resistance to RKN, which represents an important genetic contribution to sustainable cotton production in tropical environments. Made available in DSpace on 2022-02-08T19:00:51Z (GMT). No. of bitstreams: 1 BRS-500-B2RF-TRANSGENIC-COTTON-CULTIVAR.pdf: 349222 bytes, checksum: 9d7c3e73e016eb49429003d4e8546408 (MD5) Previous issue date: 2021 more...

Over the last few years, considerable effort has been spent by Embrapa in the construction of a plant disease database representative enough for the development of effective methods for automatic plant disease detection and recognition. In October of 2016, this database, called PDDB, had 2326 images of 171 diseases and other disorders affecting 21 plant species. PDDB size, although considerable, is not enough to allow the use of powerful techniques such as deep learning. In order to increase its size, each image was subdivided according to certain criteria, increasing the number of images to 46,513. Both the original (PDDB) and subdivided (XDB)databases are now being made freely available for academic research purposes, thus supporting new studies and contributing to speed up the advances in the area. Both collections are expected to grow continuously in order to expand their reach. PDDB and XDB can be accessed in the link https://www.digipathos-rep.cnptia.embrapa.br/. Made available in DSpace on 2019-06-27T01:08:27Z (GMT). No. of bitstreams: 1 ID443892018v16n6p1749IEEELatinAmericaTransaction.pdf: 892792 bytes, checksum: fb724ff1aa6fdafc4f179b63ac2bd4c1 (MD5) Previous issue date: 2018 O título da revista foi grafado no artigo como IEEE LATIN AMERICA TRANSACTIONS, mas registro de título do periódico é REVISTA IEEE AMÉRICA LATINA. more...

A cultivar BRS-336 possui alta qualidade de fibra de sequeiro e tem ampla adaptação às áreas de cultivo de algodão, com resistência ao crestamento bacteriano. A BRS 336 exibiu comprimento de fibra superior a 32,0 milímetros em todos os testes de campo. Além disso, a resistência das fibras superou todas de algodão herbáceo atualmente cultivados no Brasil. more...