Abstract: BRS 500 B2RF is a high-yielding cotton cultivar with transgenic resistance to lepidopteran pests and tolerance to the herbicide glyphosate. Additionally, BRS 500 B2RF has resistance to Ramularia leaf spot and partial resistance to root-knot nematode. It represents an important contribution to sustainable cotton production in Brazil.

Abstract Cultivar BRS 433FL B2RF is a high-quality fiber upland cotton with high lint yield potential and resistance to several diseases. The introgressed transgenic events Bollgard II® and Roundup Ready Flex® confer enhanced resistance to lepidopteran pests and tolerance to the herbicide glyphosate, respectively. Fiber length exceeds 32.5 mm and fiber strength 33 gf tex-1.

Abstract BRS 372 and BRS 416 are cotton cultivars with high lint yield and genetic resistance to the main cotton diseases in Brazil, particularly to Ramularia Leaf Spot. They have stable yields, good fiber quality and can contribute to a sustainable cotton disease management in tropical environments.

ABSTRACT: The root system architecture (RSA) of plants and its functioning play a fundamental role in a number of plant growth mechanisms including water and nutrient uptake. Optimization of the RSA is important for stable and increased plant productivity under adverse conditions. Despite its great importance, studying the RSA is notoriously laborious because of the difficulty of accessing the rooting system of plants. We developed a root phenotyping platform, PhenoRoots, which allows for the non-invasive study of plant RSA. The system was built using inexpensive material and was designed to provide medium throughput. Substrate or soil-filled rhizotrons are used to grow plantlets, whose roots are directly visible through a glass plate. An experiment conducted on a panel of twenty Upland cotton (Gossypium hirsutum L.) varieties demonstrated the usefulness of the platform in assessing RSA traits. A number of traits, destructive and non-destructive, related to the RSA were measured and statistically analyzed. The non-destructive traits based on image analysis of roots were more accurate and showed high correlation with the time-consuming destructive measurements. The platform allowed for capturing the phenotypic and genetic variability found in the panel of cotton varieties, and to define three contrasting RSA patterns. PhenoRoots provides an inexpensive alternative to the medium throughput analysis of RSA traits in plants.

Abstract Transgenic cotton cultivars BRS 430 B2RF and BRS 432 B2RF, medium and late season respectively, were developed by EMBRAPA in partnership with Bahia Foundation, aiming to create a high-yielding germplasm. The Bt toxins Cry1Ac and Cry2Ab target lepidopteran pests and the CP4-EPSPS gene confers tolerance to the herbicide glyphosate.

Abstract Cotton cultivar BRS 368RF was developed by EMBRAPA in a partnership with the Bahia Foundation, aiming to create high-yielding germplasm by adding transgenic traits addressed to Brazilian Savanna (cerrado) of the Northeast and North regions. BRS 368RF is a midseason cultivar and has yield stability and transgenic tolerance to glyphosate.

Abstract Cottonseed yield data of 17 genotypes, of which two genotypes contributed to more than 30% of the total ecovalence, and grown in 23 locations, were used to compare four methods of disjoint environmental stratification: a) environmental index (Ie): favorable or unfavorable environments; b) stratification in partitions that maximize the sum of squares of the genotype x partition interaction [(GP)m]; c) environmental scores of the second principal component of the GGE analysis (PC2-GGE); d) environmental scores of the first principal component of the AMMI analysis (PC1-AMMI). Scenarios were simulated (10,000 simulations per scenario) using combination of nine or 13 environments and 11 genotypes, either including or excluding those with the highest ecovalence values. In all scenarios, the greatest selection gains were obtained via PC2-GGE stratification, and the lowest selection gains were obtained via Ie. The ecovalences of the genotypes influenced the results obtained using the stratification methods.

Abstract 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.

A mancha de ramulária causada por Ramularia areola é uma das mais importantes doenças para a cultura do algodoeiro no Brasil. Para o controle efetivo da doença, são necessárias 5-9 aplicações de fungicidas em cultivares suscetíveis. O objetivo do presente trabalho foi avaliar, in vitro e in vivo, o potencial de esporulação de isolados de R. areola, originários de diferentes regiões do Brasil, sob diferentes regimes de temperaturas. A produção de esporos foi avaliada em laboratório e em folhas de plantas de oito cultivares de algodoeiro em condições de casa-de-vegetação. Os resultados obtidos in vitro indicaram que o potencial de produção de esporos foi dependente da temperatura. A máxima esporulação do fungo ocorreu com 17ºC para isolados originários do Estado de São Paulo e 23ºC para isolados de Goiás e Mato Grosso. No estudo in vivo, houve variação na esporulação em função da cultivar e do isolado. A maioria dos isolados apresentou alta agressividade na cultivar FM 966 LL e DELTAOPAL. Com os resultados obtidos, é possível indicar uso mais racional de fungicidas, cultivares que apresentaram menor esporulação do fungo, além de formar base para novos estudos com relação à variabilidade desse fungo em algodoeiro no Brasil. Esse é o primeiro relato sobre o potencial de esporulação de isolados brasileiros de R. areola.

Ramularia blight, caused by Ramularia areola, is one of the most important diseases affecting cotton crop in Brazil. For its effective control, 5-9 fungicide applications on susceptible cultivars are necessary. The aim of the present study was to evaluate, in vitro and in vivo, the sporulation potential of R. areolaisolates from different Brazilian regions at distinct temperatures. Spore production was assessed in the laboratory and under green house conditions by using leaves from plants of eight cotton cultivars. The in vitro results indicated that the potential of spore production was dependent on temperature. Maximum sporulation of the fungus occurred at 17°C for isolates from São Paulo State and 23°C for isolates from Goiás and Mato Grosso States. In the in vivo study, there was a variation in spore production according to the cultivar and the isolate. Most isolates showed to be highly aggressive on cultivars FM966 LL and DELTAOPAL. The obtained results suggest a more rational use of fungicides and cultivars with decreased fungal sporulation and can form the basis for further studies of the pathogenic variability of this fungus in cotton crops in Brazil. This is the first report on the sporulation potential of Brazilian R. areola isolates.

O objetivo deste trabalho foi avaliar o fracionamento isotópico do carbono como facilidade fenômica para a seleção de algodoeiro em ambientes contrastantes e analisar a sua correlação com os componentes de rendimento. Foram conduzidos experimentos em blocos ao acaso, com quatro repetições, em Santa Helena de Goiás (SHGO) e Montividiu (MONT), GO. A análise da discriminação isotópica do carbono (Δ) foi realizada em 15 linhagens e três cultivares. Em seguida, foram determinadas a cinética de crescimento e a arquitetura do sistema radicular a partir de genótipos selecionados anteriormente. Em ambas as localidades, as análises de Δ mostraram-se adequadas para discriminar os genótipos de algodoeiro. Houve correlação positiva entre Δ e a produtividade de algodão em caroço em SHGO, onde o deficit hídrico foi mais severo. Neste local, as correlações negativas encontradas entre Δ e a percentagem de fibras indicam um efeito integrativo de trocas gasosas sobre Δ e sua associação com componentes de rendimento. Quanto à robustez e à cinética de crescimento do sistema radicular, o desempenho do genótipo GO 05 809 contribui para sustentar os maiores valores de Δ encontrados em MONT, onde as condições edafoclimáticas foram mais adequadas para o algodoeiro. O uso da análise de Δ como facilidade fenômica pode auxiliar a seleção de genótipos de algodoeiro, para a obtenção de plantas com maior eficiência quanto à troca gasosa e ao uso da água.

The objective of this work was to evaluate the carbon isotope fractionation as a phenomic facility for cotton selection in contrasting environments and to assess its relationship with yield components. The experiments were carried out in a randomized block design, with four replicates, in the municipalities of Santa Helena de Goiás (SHGO) and Montividiu (MONT), in the state of Goiás, Brazil. The analysis of carbon isotope discrimination (Δ) was performed in 15 breeding lines and three cultivars. Subsequently, the root growth kinetic and root system architecture from the selected genotypes were determined. In both locations, Δ analyses were suitable to discriminate cotton genotypes. There was a positive correlation between Δ and seed-cotton yield in SHGO, where water deficit was more severe. In this site, the negative correlations found between Δ and fiber percentage indicate an integrative effect of gas exchange on Δ and its association with yield components. As for root robustness and growth kinetic, the GO 05 809 genotype performance contributes to sustain the highest values of Δ found in MONT, where edaphoclimatic conditions were more suitable for cotton. The use of Δ analysis as a phenomic facility can help to select cotton genotypes, in order to obtain plants with higher efficiency for gas exchange and water use.

Inicialmente objetivou-se investigar a possibilidade de uso da discriminação isotópica do carbono (Δ) para distinguir genótipos de algodoeiros submetidos ao déficit hídrico. Adicionalmente à ∆, o potencial hídrico foliar e as trocas gasosas foram monitorados durante a progressão do estresse. Em uma segunda fase, buscou-se verificar a utilidade da ∆ como ferramenta para seleção de plantas com alto desempenho quanto a componentes de rendimento sob condições de campo em ambientes contrastantes, especialmente quanto ao regime hídrico, utilizando linhagens elites brasileiras. Sob deficiência hídrica, verificaram-se diferenças acerca dos genótipos para ∆ (p < 0.0001) a qual também correlacionou-se significativamente com as de trocas gasosas. Em condições de campo, ∆ também discriminou os genótipos (p < 0.0001 e 0.0157 para Santa Helena de Goiás e Montividiu, Estado de Goiás, respectivamente). Verificou-se correlação significativa entre Δ e a produção de algodão em caroço onde o déficit hídrico foi mais severo (Santa Helena de Goiás). Todavia, Δ correlaciou-se negativamente com a percentagem de fibras. Então, a Δ poderá ser utilizada na fenotipagem de algodoeiro sob déficit hídrico sendo incorporado aos procedimentos de seleção de linhagens junto aos programas de melhoramento do algodoeiro visando alto rendimento sob condições desfavoráveis, a exemplo da ocorrência de déficit hídrico.

The initial goal of this study was to measure the efficiency of carbon isotope discrimination (Δ) in distinguishing between cotton plant genotypes subjected to two water regimes. In addition, ∆ measurements, leaf water potential and gas exchange ratios were monitored. Using Brazilian breeding lines, this study also tested the usability of ∆ as a proxy for selecting high-performing yield components in cotton plants grown in unfavorable conditions, particularly water deficiency. For these experiments, ∆ and yield components were measured and their correlations analyzed. Differences among cotton genotypes for Δ (p < 0.0001) were verified, and it was found that this variable was significantly correlated with gas exchange. There was a significant positive correlation between Δ and seed cotton yield only in the site experiencing severe water deficiency (Santa Helena de Goiás). However, Δ had a significant negative correlation with fiber percentage. Our results indicate that Δ is a suitable tool for cotton phenotyping, and it may be applied in cotton breeding programs that aim to produce high-performing yield components in unfavorable conditions.

A ocorrência de estresses bióticos e abióticos pode alterar o balanço hormonal e desencadear a ativação de vias envolvidas nas respostas do algodoeiro a estresses, resultando na abscisão de botões, flores e maçãs em desenvolvimento e em menor rendimento de algodão em caroço e de fibras. Como parte desses mecanismos que primariamente regulam as respostas protetivas da planta contra estresses, o etileno é considerado um hormônio chave, envolvido nessas respostas e aumentos em seu nível de síntese têm sido verificados em plantas submetidas a quaisquer tipos de estresse. Assim, o desenvolvimento de estratégias objetivando mitigar os seus efeitos negativos poderia reduzir a taxa de queda de estruturas reprodutivas e impactar positivamente na produtividade de fibras. Com esse propósito, 1-methylcyclopropeno (1-MCP), um composto inibidor da ação do etileno e aminoethoxyvinylglycina (AVG), um inibidor da sua síntese foram aplicados sobre o algodoeiro para investigar seus efeitos sobre o rendimento de algodão em caroço, de fibras, a percentagem de fibras e o stand final de plantas durante duas estações de crescimento (2010 e 2011). Assim, experimentos a campo em delineamento blocos casualizados completo com cinco repetições foram conduzidos. Os resultados obtidos evidenciam que os inibidores da síntese e da ação de etileno aumentaram o rendimento de algodão em caroço e de fibras em ambas as estações de crescimento. Os resultados obtidos pelo uso do AVG aplicado na fase reprodutiva inicial (primeiro botão floral) evidenciaram os maiores valores para os componentes de rendimento analisados, sendo os primeiros resultados obtidos no Brasil com tal propósito.

Biotic and abiotic stresses can alter the hormone balance and trigger the activation of pathways involved in the cotton stress responses, resulting in the abscission of squares, flowers and young bolls and consequent reductions in the seed cotton yield and fiber yield. As part of the mechanism that primarily regulates the protective response of plants against stresses, ethylene is considered a key hormone involved in this response, and increased ethylene synthesis has been observed when plants are subjected to stress. Thus, the development of strategies aimed to mitigate their negative effects can reduce the shed rate of reproductive structures and positively impact cotton productivity. For this purpose, 1-methylcyclopropene (1-MCP), a compound that inhibits the action of ethylene, and aminoethoxyvinylglycine (AVG), an ethylene synthesis inhibitor, were sprayed on cotton plants to investigate their effects on the seed cotton yield (SCY), fiber yield (FY), fiber percentage (% Fiber) and final stand of plants (STAND) during two cotton growth seasons (2010 and 2011). To this end, experiments were performed in a randomized complete block design with five replicates. Our results demonstrate that the inhibitors of ethylene synthesis and action increased the seed cotton and fiber yield during both growing seasons. The results obtained after AVG spraying in the initial reproductive phase (first square emission) presented the highest values for the cotton yield components and are the first record of the success of this method in Brazil.

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.

A cultivar de algodoeiro BRS 336 possui alta qualidade de fibra, adaptação às principais regiões produtoras de algodoeiro no Brasil e resistência à mancha angular. BRS 336 possui comprimento de fibra acima de 32,0 mm e resistência da fibra superior às demais cultivares em uso no Brasil.

Cotton cultivar BRS 336 is a high-quality fiber upland cultivar and has wide adaptation to the Brazilian growing areas, with resistance to bacterial blight. BRS 336 exhibited fiber length higher than 32.0 mm in all field tests. Also, fiber strength exceeded all upland cotton currently grown in Brazil.

A transmissão planta-semente de Colletotrichum gossypii var. cephalosporioides, agente causal da ramulose do algodoeiro, não tem sido correlacionada com a severidade da doença no campo. Entretanto, baixos níveis de incidência têm, muitas vezes, resultado em altos índices de infecção das sementes pelo patógeno. Esse fato induz o cancelamento de campos de produção de sementes em algumas regiões produtoras. Este trabalho teve como objetivo avaliar o efeito de níveis de inóculo inicial, constituído de plantas com sintomas da doença, em relação à incidência da ramulose quando 70% das maçãs estavam formadas, período considerado como de maior suscetibilidade à infecção, bem como a transmissão planta-semente em relação aos níveis de incidência da doença no campo. O experimento foi conduzido durante os anos agrícolas de 2006 e 2007, com níveis de inóculo inicial de 0,0; 0,1; 0,2; 0,4; 0,8 e 1,6% de plantas com sintomas aos 40 dias após a emergência, em blocos casualizados com quatro repetições e parcelas com oito linhas de 15 m. A incidência da ramulose foi avaliada quando 70% das maçãs estavam formadas, em 200 plantas, nas quatro fileiras centrais. Após a colheita, as sementes foram submetidas ao teste de sanidade pelo método do papel de filtro. Observou-se correlação significativa entre os níveis de inóculo inicial e a incidência da doença quando 70% das maçãs estavam formadas, bem como entre os níveis de incidência no campo e a incidência do patógeno nas sementes, sendo esta correlação altamente significativa no ano de 2006. Campos de produção com incidência de ramulose acima de 5% podem induzir níveis elevados de infecção nas sementes.

The transmission of Colletotrichum gossypii var. cephalosporioides from plant to seeds of cotton, normally, does not have correlation with disease severity in the field. However, low incidence of the disease, sometimes is associated with high infection of the pathogen in the seeds that is one of the causes of rejection of seed production fields in some regions of Brazil. This research had the objective to evaluate the effect of source of inoculum from diseased plants, in relation to incidence of ramulosis when 70% of bolls were developed and the relation between the incidence of disease in the field and the infection of cotton seeds. The experiments were carried out during two seasons in 2006 and 2007 with 0,0; 0,1; 0,2; 0,4; 0,8 and 1,6% of incidence, 40 days after emergence in randomized blocks with four repetitions and parcels of eight planted lines of 15 m of lenght. The incidence of disease was evaluated when 70% of bolls were completely developed in 200 plants in the four central lines. After the harvest the seeds were submitted to health test through the blotter method. It was verified high correlation between initial inoculum and incidence of disease when 70% of bolls were developed and incidence of disease in the field and infection of cotton seeds by the pathogen. The correlation was higher in 2006 than in 2007. Seed production fields with incidence of disease higher than 5% can cause high incidence of the pathogen in the cotton seeds.